Abstract: An instantaneous fluid heating system includes a fluid source, a use point for intermittently demanding fluid from the fluid source, an instantaneous IR gas heater, and a temperature sensor positioned external to the heater. The instantaneous IR gas heater is interposed operatively between the fluid source and the use point. The temperature sensor controls the regulation of the heater in response to output fluid temperature.

Abstract: An automatic modulating regulator device and method of operation for use with a non-electrical hot water heat source supplied by a pressurized water supply. The hot water heat source has a hot water circuit to pump hot water to heat exchange elements. The regulator device comprises a valve which when a power failure occurs changes to a normally open state. The regulator device is adapted to be connected to a hot water return conduit of the hot water circuit. A self-powered thermostatic valve is responsive to a temperature sensor and modulates the flow of hot water returned through the regulator device. A flow restrictor is connected downstream of the regulator device for releasing controlled quantities of water from the return hot water conduit to a drain.

Abstract: A manifold connects three boiler circuits and a heat exchanger circuit and an indirect cylinder heated exchanger circuit of a central heating system together. The manifold comprises a container which defines a hollow interior region which is divided by a horizontally extending partition plate into an upper flow water region and a lower return water region. First ports are provided for connecting flow pipes of the circuits into the flow water region of the manifold and second ports are provided for connecting the return pipes of the circuits into the return water region of the manifold. A communicating opening and apertures in the partition plate communicate the flow and return water regions. The partition plate stratifies the water within the hollow interior region so that the hottest flow water is above while the cooler return water is below the partition plate.

Abstract: A control unit and a related method of operation for controlling the temperature of the water circulated in the radiant loop of a hydronic heating system. The control unit includes temperature setting dials that can be used to adjusts the reset curve used to determine the desired secondary, radiant loop water temperature. The control unit generates a linear reset curve between two setpoints such that the control unit can calculate a desired secondary loop water temperature based on the reset curve and the present outdoor air temperature. The control unit monitors the temperature of the water returning to the boiler from both the primary loop and the secondary, radiant loop. The control unit monitors the return water temperature over a first interval and, based on the rate of change in the return water temperature, calculates a predicted return water temperature at a second interval in the future.

Abstract: An apparatus and method are disclosed for supplying domestic potable hot water and also heating an air space using a single combination unit having a common water tank and heat source for heating water therein. The water tank has an outlet for the supply of heated potable water and an inlet for the replenishment of same with cold water. A portion of the hot water is recirculated through a heat exchanger mounted in an air handler or housing. The air handler has a blower for passing the room air through the heat exchanger to heat the air space. The temperature drop of the water circulating through the heat exchanger is limited to 6.degree. F. by using a low pressure drop heat exchanger and a relatively high flow rate circulating pump, so the supply of potable hot water is always sufficient. Air heating is suspended if the heated air drops below 115.degree. F.

Abstract: A hydronic heating system having a source of hot supply water and a reservoir of cooler return water, a supply water line from the source, a return water line to the reservoir and a multitude of heating loops through which water flows to deliver heat, including: a main distribution station having a supply header, main heating loops, and a return header with a pump compelling circulation within the main station so that heat from the source flows to the main heating loops; and one or more satellite distribution stations, each with a supply header feeding water to satellite heating loops, and a satellite return header and pump compelling circulation within the satellite station; and a satellite injection water line and return water line for circulating some hot water from the main station to each satellite station so that heat from said main station flows to each satellite station.

Abstract: A heat transfer system for use with a conventional fireplace for radiating heat at a remote location from the fireplace. The heat transfer system includes a network of interconnecting conduit sections charged with an internal fluid medium and consists of a plurality of coils located within the fireplace so that the fluid medium is subjected to heat generated within the fireplace. The conduit network further includes a radiant convection device for convecting the heat generated within the fluid medium to the surrounding area and an expansion tank located on a cool side of the convection device for storing a volume of the medium for subsequent redelivery to the fireplace coils. A series of first, second and third valves are located along the conduit network and separate the fireplace coils and radiant convection device, the convection device and the expansion tank, and the expansion tank and the fireplace coils, respectively.

Abstract: An improvement is disclosed for a boiler leak system that (a) measures fluid input into the recovery boiler system, (b) measures fluid output from the recovery boiler system, and (c) calculates fluid leakage loss based on an average difference between the measured fluid input and output values. The improvement increases the accuracy and responsiveness of calculating and interpreting the difference between the input and output fluid flow of the boiler. One aspect of the invention is an improved method which includes (1) compensating for the effects of boiler drum swelling and shrinking; (2) using multiple time frames to calculate the average differences between input and output such that a balance is struck between a highly responsive leak indication (short time frame) and a highly accurate leak indication (longer time frame); and/or (3) indicating a leak only after a predetermined certain sequence of significant differences between input and output is reached.

Abstract: A hot-water heating system has a heater for producing hot water, a heat radiator, a supply pipe for supplying them hot water from the heater to the heat radiator, a return pipe for returning the heat radiator to the heater, and a circulation pump for circulating the hot water from the heater successively through the supply pipe, the heat radiator, and the return pipe. A supply pipe temperature sensor for detecting the temperature of the hot water flowing through the supply pipe is mounted on an outer surface of the supply pipe. A return pipe temperature sensor for detecting the temperature of the hot water flowing through the return pipe is mounted on an outer surface of the return pipe. A control unit controls the circulation pump to reduce an output rate thereof as the difference between the temperatures of the hot water detected by the supply pipe temperature sensor and the return pipe temperature sensor is reduced.

Abstract: A summer operation apparatus for a circulating water heating system includes a separate auxiliary device installable in connection with the system controller. The auxiliary device includes an external temperature sensor for sensing the outside temperature and also a first switching device for controlling the system pump. A second switching device converts the signal of a signal line of the temperature sensor of a controller so that it can shut the system valve. The auxiliary device also includes a control for controlling the first and second switching devices according to the external temperature thereby implementing a summer operation state for pump and valve. A timer device can be included for starting the pump intermittently in the summer operation state for short periods at a time.

Abstract: A plurality of flow control valves is correspondingly provided to a plurality of heater core portions. Each of the flow control valves is provided with a first restriction portion formed in an inlet for receiving hot water, a second restriction portion in an outlet for introducing hot water to the respective heating heat exchange portions, and a bypass opening opened at an intermediate pressure portion between the first restriction portion and the second restriction portion. Each opening area of the first restriction portion, the second restriction portion, and the bypass openings is regulated by a cylindrical valve. The first and second restriction portions, the bypass openings and the valve bodies are accommodated within a common housing, and a bypass passage communicating with the bypass openings is formed in the common housing.

Abstract: The system allows selective supply of heat energy to consumers at different temperature levels. A carrier medium heated in at least one heat source such as an environmental collector and a heat pump. An outlet line of the heat source communicates with the inlet of at least one distributor. The distributor has several outlets communicating with flow lines leading to the consumers. The distributor selects the flow line through which the heated carrier medium is to be transported, i.e. which one of the consumers is to be supplied with heat energy.

Abstract: A hydronic heating system including a single self-contained hydronic control unit. The hydronic control unit allows for zoned heating operation in which a series of individual room thermostats and zone valves control the flow of heated water into each of the heating zones. The hydronic control unit operates an oil or gas fired boiler to maintain boiler water temperature at a selected value. The hydronic control unit includes a priority terminal which can be connected to a priority heating zone, such as an indirect fired water heater. Upon receiving a demand for heat from the priority heating zone, the hydronic control unit diverts the flow of heated water from the boiler to the priority zone exclusively. The hydronic control unit further includes a terminal for connection of an outdoor air sensor. In cooperation with the outdoor air sensor, the hydronic control unit can operate in a boiler reset operating mode such that the boiler temperature is related to the outside air temperature.

Abstract: A heating system for heating a building with at least a first zone and a second to be heated. The heating system includes a first heating source and a second heating source. The heating system alternates between two modes of operation. In the first mode, heat is transferred to the first zone from the first heating source and heat is transferred to the second zone from the second heating source. In the second mode of operation, heat is transferred to the first zone from the second heating source and heat is transferred to the second zone from the first heat source. Each zone may comprise one or more areas of the building. Heat exchangers and thermostats positioned in each area control the amount of heat which is ultimately transferred into the areas.

Abstract: An engine-driven heat pump system is disclosed in which the waste heat from the engine is used to only heat the water contained in a water heater. Space heating may be then provided by circulating the water through an air-handling unit. In order to simplify the operation, the engine's coolant is circulated through a tube surrounding the heater's storage tank. Any risk of contamination to the potable water supply is removed by venting the region surrounding the coolant-to-water heat exchanger. This is achieved by assuring that a surrounding insulation layer does not form a seal over the heat exchanger and by using a non-setting thermally conductive paste between the tube and tank.

Abstract: The invention relates to a heating installation. The installation comprises a closed liquid circuit which is under pressure during operation, a pressureless liquid reservoir, an actuable pump with an inlet connected to the reservoir and an outlet connected to the circuit, actuable draining means for draining liquid out of the circuit to the reservoir, pressure detecting means for detecting the pressure in the circuit and control means for activating the pump when exceeding of a minimum pressure in negative direction is detected and for activating the draining means when exceeding of a maximum pressure in positive direction is detected.

Abstract: A hydronic heating system having a source of hot supply water and a reservoir of cooler return water, a main hot supply water circulation path (loop) from the supply water line to the return water line including a pump maintaining continuous flow of hot supply water through the main loop, a satellite injection water connection and a satellite return water connection along the main loop, a satellite distribution station including a satellite heating loop, a satellite supply header and satellite return header at opposite ends of the satellite heating loop and a satellite station pump having an input and an output for pumping satellite water from the satellite return header to the satellite supply header, whereby the satellite water flows through the satellite heating loop, a satellite injection water line from the satellite injection connection to the satellite pump input and a satellite return water line from the satellite pump output to the return connection along the main loop, whereby heat from the main loo

Abstract: A heating system that allows independent control of the temperatures within different rooms in a building by independently controlling the flow of heating fluid to each room in response to a thermostat provided in each individual room. The output of the thermostat controls the operation of a three-way valve upstream of a radiator or convector in each room. When the room temperature is at or above the setpoint for that room, the valve operates to divert all heating fluid flow through a bypass pipe or shunt extending from the valve to the outlet of the radiator or convector. When the temperature drops below the setpoint, the valve operates to resume heating fluid flow through the radiator or convector while shutting off heating fluid flow through the bypass pipe. In another embodiment, independent control of room temperature in heated air distribution systems, is effected by thermostatically controlled louvers provided at the heated air register in each room.

Abstract: A water heating system for a number of apartments or offices 10 each having a water store 15 for receiving hot water from a common boiler 12. The system includes a temperature sensor S2 for sensing the temperature of incoming water from the boiler, with a valve V1 between the temperature sensor S2 and the water store 15. A further temperature sensor S1 senses the temperature of water within the store 15. An electronic controller 30 controls the flow of water via valves V1, V2 dependent on the temperature detected by both the first and second sensors to prevent water being received by the store when the temperature differential is too small. This avoids the risk of reduction of the water temperature within the store 15, and meter 21 will not register utilization under these circumstances as valve V2 allows the return of the water other than via store 15.

Abstract: A method of operating a fluid control system and a distribution valve thereto. The fluid control system comprises a heat source (1) for a heat medium and several distribution valves (6) for distribution of heat medium to several heat consumers (8). Cold return heat medium from each heat consumer is returned to the heat source via a pump (10). To each distribution valve is transmitted warm heat medium from the heat source and cold return heat medium, which are mixed in the distribution valve in accordance with the heat requirement of the corresponding heat consumer. The fluid flow to each heat consumer is constant and is adjusted at the installation of the fluid control system. Thence, the fluid flow is maintained constant and the mixture ratio is adjusted independent of the fluid flow. This means that the fluid flow pump will work under constant flow leading to constant pressure over the pump.

Abstract: A method for automatically adjusting the temperature of the boiler water in a hot water heating system in proportion to changes in the heat demand rate in the space heated by the boiler water wherein the change in heat demand rate is established on the basis of the off-time interval in the cyclic off and on activation of the pump which circulates the boiler water through heat radiators in the space being heated. The circulating pump off times are measured, and the boiler water temperature is continuously measured. The change in space heat demand rates is calculated by calculating the change in the length of the off-time intervals of the circulating pump. The boiler water control circuits are activated to adjust the boiler water temperature control set points upward or downward in direct proportion to the change in the calculated space heat demand rate. Apparatus for conducting the method.

Abstract: An integrated zoning circulator includes a priority controller, integral with the zoning circulator, for determining the priority given to the circulator in an individual zone of a multi-zone hydronic system. The zoning circulator also includes a priority circulator system for a multi-zone hydronic system having a zoning circulator at each zone, a plurality of control boxes each having a thermostat, one control box being associated with each circulator, and, a plurality of priority controllers, one priority controller being associated with each control box. Each priority controller, when activated, functions to assure that when the associated thermostat calls for the circulator to operate, other circulators in non-priority mode are prevented from operating simultaneously.

Abstract: A hydronic heating system having a source of hot supply water and a reservoir of cooler return water, a supply water line from the source, a return water line to the reservoir and a multitude of heating loops through which water flows to deliver heat, including: a main distribution station having a supply header, main heating loops, and a return header with a pump compelling circulation within the main station so that heat from the source flows to the main heating loops; and one or more satellite distribution stations, each with a supply header feeding water to satellite heating loops, and a satellite return header and pump compelling circulation within the satellite station; and a satellite injection water line and return water line for circulating some hot water from the main station to each satellite station so that heat from said main station flows to each satellite station.

Abstract: A hydronic heating system having a boiler system supplying relatively hot supply water in a boiler supply line to a heating body or to a heat exchanger that feeds hot water to such a body and a boiler return water line feeding relatively cool boiler system water to the boiler for heating in the boiler has a three-way modulated valve in the boiler system for feeding some of the boiler supply water to the return water line to raise the temperature of the relatively cool boiler system water fed to the boiler for heating in the boiler so that it does not "cold shock" the boiler, includes a control system for the valve that varies the flow of supply water fed to return water line return water raised temperature detector providing feedback control to the valve so that: the flow of supply water to the return water line is increased when the return water raised temperature decreases and so avoid "cold shock" of the boiler; and the flow of heat to the heating body is reduced to avoid "hot shock" to the heating body.

Abstract: A method and apparatus for coupling a primary loop with a secondary loop for circulating processing fluids therebetween comprising in combination: a first connection for the feed line of the primary loop and a second connection for the return line of the primary loop; a third connection for the feed line of the secondary loop and a fourth connection for the return line of the secondary loop; a crossover line coupling the four connections; first valve means for controlling the flow through the secondary loop; first sensor means responsive to the temperature associated with the secondary loop to control the first valve means; second valve means in the path of flow through the crossover line; and second sensor means responsive to the flow of the process fluid across the crossover line to control the second valve means.

Abstract: A hot water supply system is provided, which includes a ring pipeline which extends through a water heater and in which water circulates, before going through tap pipelines to taps. The circulation pipelines have a substantially smaller cross-section than that of the tap pipelines. The circulation pipelines extend, for a portion thereof, in the interior of the tap pipelines before terminating openly in a region of a tap. A pipe branch piece is included, which is in the form of a continuous pipe and forms a component of the tap pipeline. A branch pipe of the pipe branch piece receives the circulation pipeline. The branch pipe forms an acute angle with the tap pipeline, with the angle being opened opposite to the flow direction in the tap pipeline. The section of the circulation pipeline, which extends to the tap, is inserted endways into the branch pipe, while the remaining section of the branch pipe joints at the branch pipe and at the ring pipeline.

Abstract: A method and apparatus for heating room space of a building. According to the invention, heat is conveyed from district heating water to a heating liquid of heating circuits for heating the building, tap water and supply air of ventilation. According to the invention, the heating circuits for heating the building and the supply air are connected in series in such a manner that the heating liquid flowing in the piping heats, after passing a heat exchanger, first the heating circuit for heating the building and thereafter the heating circuit for heating the supply air. On account of the invention, the temperature of the district heating return water is lower than in the known apparatuses.

Abstract: A process is disclosed for adjusting the valve position of flow control valves which govern the flow of a heat exchange fluid to a plurality of individually controlled zones. The process resides primarily in a system controller in communication with a number of separate zone controllers. The system controller periodically obtains temperature and mode of operation information from each zone controller and thereafter computes the amount of time necessary to change the temperature by one degree in each zone. The computed amount of time per degree change in temperature is compared with the average for all zones in a similar mode of operation. Offsets are calculated for active flow control valves in each zone depending on whether the computed amount of time per degree change in temperature is above or below the average for all corresponding zones in the same mode of operation.

Abstract: A device for heating boilers (1) in heating plants comprises a means (2) for heating a heat carrying medium present in the boiler and circulating out thereof in the heating plant as well as a means (11) adapted to detect the temperature of the heat carrying medium present in the boiler and send signals to the heating means (2) to start and stop the heating of the medium when a first lower temperature level is underpassed and a second higher temperature level is exceeded, respectively, by the medium in the heating boiler (1). The device comprises further means (12) adapted to delay the start of the heating means (2) when the first temperature level is reached by the medium and this is detected by the detecting means (11).

Abstract: An integrated wet-rotor zoning circulator for circulating fluid within a zone in a hydronic heating or cooling system. The zoning circulator has three primary components: a motor, an impeller casing, and a controller. The controller, which is integrated with the motor, houses a voltage transforming device (e.g., a transformer) and a switching device (e.g., a relay). When a thermostat in the zone being served by the zoning circulator closes, the switching device closes and the pump is activated.

Abstract: A boiler controller for hydronic heating systems that reduces the standby heat losses from boiler to a minimum and activates the boiler automatically when hot water or/and space heating demand are present.

Abstract: A dual tank water heating system has an exterior tank which surrounds an interior tank. Water in the exterior tank is maintained at a prescribed temperature by heating elements located beneath the outer tank. Water in the interior tank is heated by water in the exterior tank and, when necessary, may be heated by a secondary heating element located beneath the interior tank. Water in the exterior tank may be used for general residential and commercial purposes and water in the interior tank is pumped through radiators for hydronic heating. Under moderate weather conditions, all heat is provided to the radiators through water in the interior tank which has been heated by water in the exterior tank. Under particularly cold circumstances, the secondary heating element is used to boost the heating ability of the system.

Abstract: A method and apparatus for coupling a primary loop with a secondary loop for circulating processing fluids therebetween comprising in combination: a first connection for the feed line of the primary loop and a second connection for the return line of the primary loop; a third connection for the feed line of the secondary loop and a fourth connection for the return line of the secondary loop; a crossover line coupling the four connections; first valve means for controlling the flow through the secondary loop; first sensor means responsive to the temperature associated with the secondary loop to control the first valve means; second valve means in the path of flow through the crossover line; and second sensor means responsive to the flow of the process fluid across the crossover line to control the second valve means.

Abstract: A valve controller for a hot water heating system having a water heating device, a water circulating device, and heater device. The Controller operates a water control valve between an open and a closed position, the valve controller comprising, a flow timer for variably establishing flow periodicity between a minimum flow time and a maximum flow time, a base cycle timer for variably establishing base cycle periodicity between a minimum base time and a maximum flow time. The base timer variably establishes a base cycle periodicity between a minimum base time and a maximum base time. A selector responsive to heat requirements for select a flow time and base cycle time.

Abstract: The apparatus of the present invention comprises a hydronic distribution system using prefabricated, flexible cable containing plastic tubing to provide liquid supply and return conduits for the hydronic system. The plastic conduits are enclosed in a foam thermal insulation material which is encased in a flexible, moisture impervious shell. In an alternate embodiment of the invention, the flexible cable includes electrical conductors for supplying power to a fan and for carrying an electrical control signal from a thermostat. The flexible cable thus described can be installed in a building easily and quickly in a manner similar to that currently used for electrical cable.

Abstract: The gas boiler is intended for room heating and producing hot water and has a gas-heated primary heat exchanger which feeds two heating circuits lying in parallel. The heat exchange medium is circulated via a rotary pump driven by an electric motor, arranged on the cold side of the primary heat exchanger and has a control mechanism which is arranged on the pressure side and controlled by speed or direction of rotation. This control mechanism serves to actuate a switch mechanism connected to the pump housing, in that it connects in series one or other heating circuit to the primary heat exchanger. The switch mechanism is arranged on the hot side of the primary heat exchanger in the pipework to the heating circuits.

Abstract: A liquid level control principally for boiling water boilers sensitive to the presence or absence of liquid at an upper and at a lower control level. The control enables the boiler to be fired when liquid is at or above the upper level. It prevents firing and enables addition of make-up liquid when the liquid level is below the upper control level, except when the system indicates there is liquid at the upper control level, and that there is no liquid at the lower control level.

Abstract: An apparatus and method for providing a hot water supply for a building such as a mobile home, house, or business. A hot water storage tank is positioned within the building. A gas-fueled burner is positioned outside the building adjacent a heat exchanger which is connected in fluid communication with the indoor water storage tank. A pump circulates water from the tank through the heat exchanger and back into the tank responsive to a thermostat in the tank. The heat exchanger includes a thermostat for sensing the temperature of water therein to activate the pump and circulate relatively warm water from the tank through the heat exchanger to prevent freezing of water within the heat exchanger, such as during winter months when the ambient temperature falls below freezing. The gas heater may be used to convert a conventional electric water heater to operate from gas which is combusted outside of the building.

Abstract: The invention is an improved method for controlling a boiler used in a building space heating system. Certain control parameters such as outdoor ambient temperature and return line water temperature are monitored and boiler firing and quiescence are controlled as a function of a combination of water and ambient temperatures. This helps limit the time required to bring the system up to operating temperature. In general, the lower the ambient, the higher will be the return line water temperature which will initiate firing. And there are combinations of such temperatures at which the boiler is maintained quiescent notwithstanding a call for heat and other combinations at which the boiler is fired in the absence of a call for heat. Several control routines are disclosed.

Abstract: A central heating plant (either single pipe or double pipe) supplies heat carrying fluid to several rooms, each having a radiator (5) provided with a thermostat valve (6). The plant has a differential pressure valve (11, 111) placed downstream of the radiators, with a closing device (24, 25) controlled by a membrane (23) for regulating the flow of heat carrying fluid in a passage (19) between an inlet (17) and an outlet (18). If the windows in several rooms are opened, the thermostat valves (6) will open, whereupon the differential pressure valve should regulate the combined flow, which a conventional valve cannot do since the pressure difference across the two surfaces of the membrane (23) is small even with full flow. This drawback is avoided by means of a differential pressure valve (11, 111) with an adjustable throttle (15) between the inlet (17) and the closing device (24, 25), and by adjusting the throttle, regardless of the pressure distribution, to allow the maximum amount of fluid to pass.

Abstract: The connection strip is for use with a dual-purpose hot water and central heating boiler. The strip comprises four modules made of molded hard plastic and assembled side-by-side by being mutually juxtaposed with tie bars passing through them, the modules being respectively associated with outgoing heating water, outgoing domestic hot water, incoming cold water, and returned heating water, each module including the corresponding stopcocks and ducts together with lengths of a short-circuit duct enabling the modules to co-operate to form a short-circuit on the heating circuit, suitable for feeding water to said heating circuits and for enabling leak tests to be performed when the boiler is not present.

Abstract: A hot water heat control system for a building having a given boundary layer heat loss characteristic is described. The heating system, which includes a water heating device, a water circulation loop, and a mechanism for varying the amount of heat to the loop, is controlled by a unique valve arrangement. In the best mode, the valve arrangement controls the water temperature supplied to the perimeter heater in response sensed changes of ambient environmental conditions. In one system configuration, a controller is used to control the flow of heated circulating water in response to the sensed weather parameters. The valve controller has a flow timer for variably establishing flow periodicity between a minimum flow time and a maximum flow time. The valve controller also has a base cycle timer for variably establishing base cycle periodicity between a minimum base time and a maximum base time.

Abstract: Domestic hot water heating control circuit is used in conjunction with a furnace control unit of a hot air furnace system which utilizes a hot water heat exchanger. The hot water control circuit has a diverter valve which is electrically connected to a thermostat which monitors a hot water tank and a fan control circuit for controlling the operation of a comfort fan for the hot air system integrated with the furnace control system. The diverter valve controls the circulation of heated water between the heat exchanger of the furnace and the hot water tank. When the hot water tank thermostat calls for heat, the diverter valve switches a relay to start the furnace and to direct heated water from the heat exchanger of the furnace to the heating coil of the hot water tank. The fan control circuit then operates to shut "off" the comfort fan to prevent cold air from being supplied to the living space in the event that the space thermostat calls for heat.

Abstract: A method and apparatus for controlling operation of a heating system (particularly a central heating system) including a boiler directly heating and passing water to a pipe network proide for sensing the temperature of the pipe network at a position therein remote from the boiler and controlling operation of the boiler in accordance with that sensed temperature. The apparatus includes switch means (operational amplifiers or comparators)--responsive to a voltage output by a device including a transducer sensing the temperature of the pipe network and--operable to allow the boiler to fire until the sensed temperature reaches a first level and then prevent the boiler firing until the sensed temperature falls below a second level less than the first. The two temperature levels may be varied, and the second level may be varied in dependence upon an ambient temperature remote from an area being heated.

Abstract: A multiple-boiler heating system is disclosed in which each boiler or stage is provided with an adjustable firing level of modulation at which the boiler is turned on and an adjustable threshold level of modulation (the MOD point), below which the next stage is disabled from being turned on. A control device for the heating system continuously compares temperature in the area being heated to the set point for the system and determines the total change in system output level ("DUTYCHANGE") which would be required to produce a specified temperature within a predetermined time. Should DUTYCHANGE be negative, it is similarly distributed among the stages which are turned on. However, the reduction in modulation level proceeds backwards from the last stage which was turned on. When the last stage reaches its firing point, it is not turned off until the previous stage drops below its MOD point. The lead stage is turned off as soon as it reaches its firing point.

Abstract: An automatic control device which periodically computes system operating costs and utilizes those computed costs to adjust a forced hot-water heating system for maximum economy. Labor and material costs required to maintain, and replace at periodic intervals, the circulation pump and boiler, as well as the energy costs to operate those units, are calculated in an iterative manner over a plurality of predetermined time intervals. The successive results are used to control the water temperature setpoint for minimum system operating costs.

Abstract: An automatic control device for a hot water heating system, comprises a first relay being connectable to a water temperature switch such that the first relay is energized when the switch is closed and a second relay connected to the first relay such that the second relay is energized when the first relay is energized. The first relay is connectable to an electrically operated valve controlling the flow of high temperature water from a boiler to a heat exchanger operably associated with a water heater such that the electrically operated valve is opened when the first relay is energized and closed when the first relay is de-energized. The first relay is connectable to the boiler such that the boiler is turned on when the first relay is energized.

Abstract: A heating system for buildings, comprising a boiler (12), a liquid circulation pump (28) and an electrical control panel (22), incorporates an electronic economizer device (26) arranged to make the circulation pump (28) operate intermittently according to cycles predetermined by the operator through timers (26a, 26b, 26c).

Abstract: A method and apparatus control firing rate in a heating system to compensate for thermal mass characteristics of the heating system. The thermal mass characteristics of the heating system are derived from heating system identification information. A weighted control response factor is selected which is representative of load characteristics of a load type affecting firing rate control and which is representative of desired control tightness. The firing rate is varied, based on the weighted control response factor and the thermal characteristics, to match the heating system, the load type being controlled and the desired control tightness for optimum control.

Abstract: A supplementary hot water heating system which transfers to a hot water tank heat from exhaust gas in the furnace stack which would otherwise be wasted. When the water in the supplementary heater core is heated to a desired temperature, normally closed valves, one connecting the heater core to the cold waterline and the other connecting the bottom of the hot water tank to a drain, are simultaneously opened and remain opened until the supplementary heater core is again filled with cold water from the cold water line.