When Your Furnace Seems Dead Check the Thermostat
It can be relatively easy to diagnose a furnace problem when it comes with a symptom of some kind — a sound or smell, for instance. Sometimes, though, furnaces completely refuse to start up. Nearly anything could be wrong with such a unit. The problem could be as simple as a lack of fuel or could be as serious as corroded parts. Before you try to fix your furnace, though, you should always think about the thermostat — the device that gauges ambient temperature and decides whether or not to let the furnace run. Troubleshooting your thermostat should be the first thing you do when your furnace seems completely dead.
To begin, check the setting
If the thermostat is set to a low temperature for some reason, it will naturally make sure that the furnace doesn’t turn on. You first move, then, should be to check the temperature setting. You could try raising the temperature to a much higher point to see if it makes the furnace come to life. If it doesn’t, your thermostat could be either defective or simply be in need of a bit of maintenance.
Anything from loose contacts to dirt buildup and power problems could make a thermostat non-functional. Your next step, then, should be to rule these possibilities out.
Rule out the basics
Thermostats work with electricity. If you have an electronic unit, a dead battery, a blown fuse or a circuit breaker that’s tripped could render it useless. You can try replacing the battery or the fuse, or try checking the circuit breaker. Loose wires are a possibility worth checking out, too. Where you see wires lead in or out of the thermostat, you could try tightening the screws.
Dirt buildup is the most common cause of malfunctioning thermostats. If your thermostat is in the kitchen, a coating of grease could be the problem. Wherever your thermostat is located, it’s always a good idea to give it a good spring cleaning each year. Going over the insides with a paintbrush can do the trick. A blast of compressed air can help, too.
If your thermostat is mechanical
Every mechanical thermostat has a component called an anticipator. It’s the metal tab that’s mounted on the temperature dial. Sometimes, wiggling the anticipator a little can help make a dead thermostat functional again. You may need to wait a few hours to make sure that the thermostat works reliably, though.
Check the level
With certain mechanical models, level mounting is important to normal functioning in a thermostat. If the device is at a crooked angle, it could work incorrectly or not work at all. You can grab a level and make sure that the device is completely straight. This could be all it takes to get it working again.
Consider getting a new thermostat: it can save you money
The most advanced thermostats today cost no more than $250 (professional installation will cost extra). By letting you program in the exact temperatures you want your home heated to at different times of the day, these thermostats easily pay for themselves with the kind of savings they create. While you certainly should try to make your existing thermostat work, you should also keep in mind that getting a new, advanced model can work out very well.