The disclosed technology includes a system and method of preventing short cycling in a water heater. The system can include a burner, a temperature sensor, and a controller. The controller can be configured to perform several steps to determine whether to turn on a burner and whether to increment a temperature offset value based on the amount of time that has elapsed since the last time the burner was on.

Control of temperature of water delivered by a dual-stage water heater having an external boiler with a first heater as first stage and an internal duct (water booster) with a second heater as second stage. A control loop based on a measured water temperature in the boiler and controls the first heater. A second loop calculate a reference booster water temperature based on the temperature error at the outlet (difference between a measured outlet water temperature and a reference outlet water temperature) and controls second heater based on error between reference booster water temperature and measured booster water temperature. The reference outlet water temperature depends on type of beverage (e.g. espresso, cappuccino) and includes a temperature profile with different temperature for different sub-beverages (e.g. coffee, milk). Takes into account physical response times, inertia of heater and anticipate sudden changes of reference water temperature at hot water outlet.

Thermal targeting technology is used to continuously adjust boiler target temperature to the minimum necessary to satisfy the required heating load. Responsive to and initiated by a first call for heat, boiler target temperature is reduced by a predetermined amount upon or subsequent to the call for heat. Once the boiler temperature reaches this new target, a call timer is activated. If demand for heat is satisfied before a time set point is reached, the system ceases providing additional heat energy until the next heat demand. Responsive to and initiated by a next call for heat, the boiler target temperature is again reduced by the predetermined amount upon or subsequent to this next call for heat. Each time the heat demand is satisfied within the predetermined time interval, the boiler target temperature is reduced. If heat demand is not satisfied, a thermal boost is provided at set time intervals until the call for heat is removed.

A water heater system includes a controller configured to integrate control of both recovery and recirculation operations of a recovery pump and a recirculation pump. As such, a separate device, installation location, and power source (e.g., available outlet) is not needed with the controller. Because a single controller is configured to control both recovery and recirculation operations, additional control functions are available. The controller may be in communication with an internal controller of the water heater and configured to receive an error notification upon abnormal operation of the water heater. The controller can stop recovery and recirculation operations in response to an error notification, unlike with traditional water heating systems which may otherwise continue to function. The recovery and recirculation operations are based on a setpoint temperature of the water heater such that changes made to the setpoint temperature will automatically adjust in the recovery and recirculation operations.

The present disclosure provides a method and a system for controlling a heat pump water heater. The method includes: receiving a turn-on instruction; detecting the current temperature of the water in the water tank and the ambient temperature; acquiring a turn-on temperature difference according to the set temperature of the heat pump water heater and the ambient temperature, and acquiring a turn-on threshold according to the turn-on temperature difference; determining whether the current temperature is less than the turn-on threshold; if no, maintaining the current state; and if yes, controlling to enable the heat pump system to heat the water in the water tank.

A water heater includes a storage tank, a sensor configured to measure a temperature of water in the storage tank, a burner configured to heat the water in the storage tank, and a controller communicatively coupled to the sensor and the burner. The controller is configured to initiate a call for heat when the measured temperature reaches a trigger temperature, wherein the trigger temperature is a differential amount less than a set-point temperature, calculate a reduced activation time when the call for heat results in a predetermined number of calls for heat occurring within a predetermined time period, and control the burner based on the reduced activation time.

A hybrid water heater incudes a storage tank, a first temperature sensor, a tankless heater fluidly coupled to the storage tank, and a controller configured to determine a target output temperature range for the tankless heater based on a temperature setpoint, measure a temperature of hot water stored in an upper portion of the storage tank using the first temperature sensor, determine whether the measured temperature of the hot water is less than a first minimum temperature setpoint, generate an adjusted target output temperature range for the tankless heater based on a determination that the measured temperature is less than the first minimum temperature by increasing a value of both the lower threshold and the upper threshold, and control the tankless heater to produce the heated water according to the adjusted target output temperature range.

A hybrid water heater incudes a storage tank, a first temperature sensor, a tankless heater fluidly coupled to the storage tank, and a controller configured to determine a target output temperature range for the tankless heater based on a temperature setpoint, measure a temperature of hot water stored in an upper portion of the storage tank using the first temperature sensor, determine whether the measured temperature of the hot water is less than a first minimum temperature setpoint, generate an adjusted target output temperature range for the tankless heater based on a determination that the measured temperature is less than the first minimum temperature by increasing a value of both the lower threshold and the upper threshold, and control the tankless heater to produce the heated water according to the adjusted target output temperature range.

A fluid heater is disclosed and which has a heater, pump, and a plurality of temperature sensors which are electrically coupled with first and second temperature controlled relays, and wherein the fluid heater is operable to maintain a source of fluid used by an object of interest within a predetermined temperature range and further, is operable under given temperature conditions to discontinue operation so as to protect the object of interest and the heater from becoming damaged through overheating of the fluid which is utilized by same.

System and methods for controlling operating state of a heat transfer system are disclosed herein. The heat transfer system can include temperature sensor positioned at the fluid inlet line and the fluid outlet line and a heat exchanger between the fluid inlet line and the fluid outlet line. The heat transfer system can include a processor communicatively coupled to the first temperature sensor and the second temperature sensor. The processor can determine an inlet temperature of water flowing in the fluid inlet line and outlet temperature of water flowing in the fluid outlet line and can determine a delta temperature based on difference between the inlet temperature and the outlet temperature. Based on the inlet temperature and the delta temperature, the processor can determine an operating state of the heat transfer system.