Stabilize the room temperature and measure it at the thermostats location. Set the dial to the temperature that was measured and adjust the thermostats branch line output to mid point of the controlled device`s operating range. For example if the range is 3-15 psi set the stat output for 9 psi when it is at setpoint. While doing this do not stand near the thermostat for extended periods, the heat from your body will be sensed by the stat and throw off the calibration. In other words work fast.
If a thermostat is not working properly, you cannot calibrate it. It must be replaced.
3% of 970 = 3% * 970 = 0.03 * 970 = 29.1
The recommended maintenance schedule for the thermostat of an oil furnace is to check and replace the batteries annually, clean the thermostat and surrounding area regularly, and have a professional HVAC technician inspect and calibrate the thermostat every 1-2 years to ensure it is functioning properly.
There are two ways to do this. Fist is there is a small nut located behind the heater coil on the thermostat. It takes a special wrench to turn this nut. You can get them where you buy your thermostat. The second way is to back off the screws that hold the backer plate to the wall and check it for level. Once it is level tighten the screws and connect the thermostat back to the backer plate.
970
967 to the nearest ten is 970
97
970 = CMLXX
970
970
970
(303) 970-6835