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Thermostat Problems and Troubleshooting

There are numerous reasons why a thermostat can stop functioning properly. It could be that the batteries need to be changed, a breaker that powers it is flipped or broken, the wiring inside is burnt out or frayed or that external factors like blocked air filters or leaky ductwork is causing it to malfunction. If you haven’t diagnosed the problem yet, turn to Experts who can give you the right solution.

Listed below are a few questions answered by electricians on Thermostat related problems.

I need to change the battery of my Lux 1500 thermostat. How do I do this?

There are two parts to a thermostat called a face and a sub-base. Gently pull the face and release the base from the sub-base. Then locate the face latch at the bottom of the thermostat where there is a small indentation. When you slowly pull the face towards you after pushing the latch, you will see two AA size batteries. Quickly change them as you only get a minute to do this to keep the memory intact.

My wood burning stove has a Honeywell thermostat at the back. The power cord has come off and I’m not sure where the white and black wires are meant to fit. Can you help?

If your thermostat is 120V, connect the black wire to the line side of the T-stat and the white wire to the white from the unit.

I have a 240 volt attic ventilation fan that is run by a double pole breaker. Can I connect a single pole thermostat to it?

This should be possible but using a 2 pole Thermostat will probably give you better results.

I need to install a new thermostat and I have four wires (blue, green, white and red) coming from the wall. The thermostat inputs read O/B, Y, RC, R, G, W. How do I connect the wires?

You should be able to connect them by following the usual wiring system:

Red to R with jumper to RC for POWER, White to W for HEAT, Green to G for FAN and Yellow to Y for COOL. In your case the Blue might be a Y.

I need to fish the wall from an unfinished basement to get a wire up it to a thermostat that I want to relocate. How do I do this?

The simplest way to go about this is to start by making a hole in the wall that the thermostat will be installed on. Ensure that the hole isn’t larger that the thermostat but is big enough to snake out the fish tape. Then find the extension of this wall in the basement and create a hole in it from the basement up. Ensure that the hole is made on the wall and not outside of it through the floor. If you have other outlets on the same wall that have wires running through it from the basement, use them as a reference for the job. After you create the hole in the basement, insert the fishing tape into it. Finally, push the tape through and pull it out of the hole in the wall upstairs.

How do I test the thermostat in my spa to know if it’s working properly?

First, check continuity by using a meter. If you get a reading when the thermostat is turned above temperature, it means that it is working.

One of the reasons why a thermostat could give you problems is because of faulty wiring. To check this, use a multimeter and examine the thermostat’s transformer. Look for continuity of wiring that extends from the transformer and adjust the multimeter to measure for infinite resistance. Next, bring the probes into contact with the exposed wiring joints or solders. If you get a reading that says that there is resistance at infinity, the problem could lie with faulty circuitry inside the thermostat. Closely examine the wiring by removing the thermostat completely, check for any burnt or frayed components and replace them. If you need further help or have your own question about thermostat problems, ask an expert.

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