Circuit Lake

Electronic Project and Circuit Collection

PIC16F74 Room Thermostat for Gas Boiler

02/27/2013 Category: Control, Monitoring, PIC

This Room Thermostat provides better controller for gas boiler. Instead using water temperature inside boiler, the device uses room temperature as parameter to switch boiler on or off through relay. The project is built based on PIC16F74 and uses 1–wire digital thermometer IC, Maxim DS1820, to sense room temperature.

Gas Boiler Controller

The device features pre-configurable temperature threshold, 0.5 degree Celsius precision and has 1 degree hysteresis which means that the boiler isn’t switched on, until the measured temperature falls below the preset temperature by 1 degree. It also comes with dedicated button to turn off heating and graphical color LCD to display temperature value and line graph of temperature history.