Erie Manufacturing Company

Roger P Michaud

Daniel K Stege

Larry Milesky

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. If the predicted return water temperature is lower than the user-selected minimum return water temperature, the control unit operates the modulating valve to reduce the amount of heated water flowing to the secondary, radiant loop.

Radiant heating system reset control

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. The hydronic control unit includes a terminal for connection of a hot water sensor, which is also connected to a safety terminal. The hot water sensor indicates the temperature of water in the boiler, and provides a safety switch should the water in the boiler exceed an upper limit. The hydronic control unit further includes connection for a low water cut-off probe that interrupts the power to the hydronic control unit should the quantity of water in the hydronic heating system fall below a minimum value. The hydronic control unit incorporates the above-identified features in a single control housing, such that only one power connection is needed for the above-identified features.

Electronic boiler control

A relay circuit for energizing a load in response to a control device and method of testing the relay circuit, in which a switch is provided for selectively disconnecting the control device from the relay circuit and activating a relay switch such that the load is energized when in a test mode and reconnecting the control device when in an operational mode. By disconnecting the control device in the test mode, the control device may be electrically isolated from the relay circuit thereby protecting the control device from damage due to backfeeding.

Growing community of inventors

Orrs Island, ME, United States of America

Roger P Michaud