A portable indirect fuel fired heater includes a burner assembly having a fuel burner to deliver fuel from a fuel supply to a combustion chamber of the heater and a combustion air blower to deliver combustion air to the combustion chamber with the fuel for combustion in the combustion chamber to produce exhaust gases. A heat exchanger receives air to be heated in heat exchanging relationship with at least a portion of the combustion chamber. A sensor senses an oxygen level as a partial pressure of oxygen in the exhaust gases. A controller operates an actuator operatively connected to the burner assembly to controllably vary the delivery rate of combustion air and thus vary the ratio of the air and fuel responsive to the oxygen level sensed by the combustion sensor so as to maintain the sensed oxygen level at a prescribed set point level stored on the controller.

A heating system of a managed fluid system can include a heat exchanger and a first temperature sensor device that measures an inlet temperature of a fluid flowing into the heat exchanger. The heating system can also include a second temperature sensor device that measures an outlet temperature of the fluid flowing out of the heat exchanger. The heating system can further include a controller communicably coupled to the first temperature sensor device and the second temperature sensor device. The controller can receive inlet temperature measurements made by the first temperature sensor device and outlet temperature measurements made by the second temperature sensor device. The controller can also evaluate the inlet temperature measurements and the outlet temperature measurements using at least one lookup table and at least one algorithm. The controller can subsequently determine an input rate of fuel used to heat the fluid flowing through the heat exchanger.

A device that includes a pressure sensor that adds dynamic pressure sensing capability to a furnace. In some examples the device may include a relay and other circuitry to replace the single-setpoint pressure switch used to sense the operation of an inducer fan. The pressure sensor may measure the pressure from the inducer fan and send a signal to the other circuitry, such as a microcontroller. The other circuitry may determine when the pressure from the inducer fan reaches a predetermined threshold and allow the main gas valve of the furnace to open. The other circuitry may be configured to set the pressure sensor to a variety of predetermined pressure thresholds, and thereby replace multiple pressure switches. In some examples, the other circuitry may record pressure values received from the pressure sensor over time and provide performance data, as well as other signals or indicators.

The disclosed technology includes a tankless liquid heater system for detecting buildup on a heating element, including: a chamber; at least one heating element to heat liquid in the chamber; at least one sensor to detect data associated with identifying buildup on the at least one heating element; and at least one device to: receive the data detected by the at least one sensor; determine, based on the data, an amount of the buildup on the at least one heating element; and adjust an operation of the at least one heating element based on the amount of the buildup on the at least one heating element.

The disclosed technology includes a tankless liquid heater system for detecting buildup on a heating element, including: a chamber; at least one heating element to heat liquid in the chamber; at least one sensor to detect data associated with identifying buildup on the at least one heating element; and at least one device to: receive the data detected by the at least one sensor; determine, based on the data, an amount of the buildup on the at least one heating element; and adjust an operation of the at least one heating element based on the amount of the buildup on the at least one heating element.

Please replace the originally filed abstract with the substitute abstract provided below. A temperature and pressure relief valve apparatus including a body having a first conduit connected to a water heater and a second conduit connected to a discharge pipe. A valve member, positioned between the first and second conduits, is normally biased closed to prevent flow between the conduits. The valve member is configured such that when a temperature or pressure within the water heater exceeds a predetermined level, the valve member opens to relieve pressure and, in turn, water is released through the second conduit. A sensor is disposed about the second conduit and coupled to a controller. The controller measures a capacitance value of the second conduit, detects a change in the capacitance value indicating a presence of water in the second conduit, and asserts an alarm condition upon detection of the change in the second conduit capacitance value.

Please replace the originally filed abstract with the substitute abstract provided below. A temperature and pressure relief valve apparatus including a body having a first conduit connected to a water heater and a second conduit connected to a discharge pipe. A valve member, positioned between the first and second conduits, is normally biased closed to prevent flow between the conduits. The valve member is configured such that when a temperature or pressure within the water heater exceeds a predetermined level, the valve member opens to relieve pressure and, in turn, water is released through the second conduit. A sensor is disposed about the second conduit and coupled to a controller. The controller measures a capacitance value of the second conduit, detects a change in the capacitance value indicating a presence of water in the second conduit, and asserts an alarm condition upon detection of the change in the second conduit capacitance value.

Disclosed herein is a water heating system including a water heater having a tank, and a first temperature sensor disposed toward a top end of the tank to measure a first temperature and a second temperature sensor disposed toward a bottom end of the tank to measure a second temperature. The water heating system can further include a controller communicably coupled to the first temperature sensor and the second temperature sensor, where the controller determines an amount of heated water in the tank based on one or more algorithms and measurements made by the first and second temperature sensors.

An automatically flushing water heater maintenance system may be provided, the system including a water heater and a water heater controller. The water heater may include an inlet, an outlet, and a flush outlet having a first control valve in flow communication therewith. The first control valve may be configured to control a flow of water and sediment through the flush outlet out of the water heater. The water heater controller may be configured to communicate with the first control valve by transmitting a first control signal to the first control valve, the first control signal configured to cause the first control valve to open or close as part of an automatic flushing process. As a result of the flushing, the useful life of the water heater may be extended, and/or water heater leakage alleviated. Insurance discounts may be provided based upon using the automatic water heater flushing functionality.

A water heating system can include a water heater having a tank, an inlet line, and an outlet line, where the inlet line provides unheated water to the tank, and where the outlet line draws heated water from the tank. The water heating system can also include multiple sensing devices, where each sensing device of the plurality of sensing devices measures a parameter associated with the tank. The water heating system can further include a controller communicably coupled to the plurality of sensing devices, where the controller determines an amount of heated water in the tank based on measurements made by the plurality of sensing devices.