By: mikeandgerry On: Wed Mar 02, 2011 1:07 am
No need to wait to calibrate your anthrastat. It can be done in about 5 minutes if you are set up ahead of time.
1. Shut off your boiler's electricity.
2. Disconnect the anthrastat wires and remove the ash probe and thermostat housing. (Don't disassemble the anthrastat.)
3. Heat a large pot of water to a temp in the range of 170 to 180 degrees using a reliable thermometer.
4. Place the anthrastat probe in the large pot of water, covering at least 3/4 of the probe. (Don't immerse the thermostat housing.)Let the probe come to pot temperature for a couple of minutes.
5. Meanwhile, loosen the set screw on the side of the black pointer (the pointer is a knob-like pointer which is not a turn knob and should not be used as a twist knob. Twisting it is likely how it became out of calibration!)
6. Attach a continuity tester between the two electrical terminals in the thermostat housing. The tester light should be off at a high temperature. If not, use a 1/8" hex key to turn the adjustment screw in the center of the pointer counter clockwise until the light goes out.
7. Using the 1/8" hex key, turn the adjustment screw slowly clockwise just until the light comes on. Stop. Note the pot water temperature.
8 Set the black pointer to the noted water temperature on the anthrastat dial and tighten the set screw.
9. Using the 1/8" hex key, turn the adjustment screw to set the anthrastat between 120 and 140 degrees. (120 for light loads, 140 for heavy loads)
10. Return the anthrastat to your boiler and reconnect the wires.
11. Turn on the boiler electricity.
12. Leave it alone for the rest of your life.