Thermostat can go bad it just depends what part of the thermostat goes bad first. Most of the time your thermostat can last years and you will probably upgrade it before it goes bad. In some cases though you could have a relay go bad and the stat will not engage the proper output to bring on ether the fan, cooling, or heating. So it may look like it is working but nothing is happening at your unit.
A good way to test this is take the thermostat off the wall a wire nut the red a green wire together and see it you fan comes on. Then wire nut the red green and yellow wire together and see if your cooling comes on. Then you could wire nut you Red green and white wire together and see if you heat come on. If this works on all three but then you hook the stat back up and nothing happens you will need to replace you thermostat.
Also your sensor could go bad. You could go buy a hand held temp sensor at a hardware store. Let it sit next to your thermostat for at least 30mins and then compare the reading to what your thermostat says. They should read within a couple degrees of each other. If you know your hand held is accurate then replace your thermostat.
Last thing is your display could be off on your thermostat. If you have a volt meter try checking for 24vac from red to any other color and if it reads then replace your thermostat. If you do not have a volt meter you can check and make sure your furnace is turned on. If the board on your furnace has light it is most likely good and your thermostat needs replace.
If you are uncomfortable with power I would just call someone to look at it but if you think there is a problem and your unit is not working go buy a cheap thermostat at the local hardware store and replace it just to test if your old one was the problem before you call someone. Keep all the packaging and return it if it wasn't the problem.
Comments