It’s good to know your furnace works and it’s better for it to stay on than to never turn on, but if the temperature outside increases in Merced County and your home turns into a sauna, it will become incredibly uncomfortable very quickly.
When such a thing happens, you probably want to know why your furnace won’t turn off. Here are a few possible issues that might be causing the problem.
- Shorted Wires – Wiring is a central component of your furnace, air handler and thermostat. So, if any of the wiring shorts out, such as the thermostat, a relay between the thermostat and the furnace or the blower itself, the furnace can stay on indefinitely. A professional will need to inspect to determine the full extent of the damage and what needs to be replaced.
- Bad Limit Switch – A limit switch is necessary to stop an electrical device from running when certain conditions are met. In the case of a furnace, that would be when the temperature in your home reaches the thermostat setting. If the limit switch goes bad, either your furnace or your blower will continue to run (and sometimes both).
- Relays – Relays are used to control the electrical components of your furnace such as the blower fan, especially when it has a multi-speed motor. If the relay goes bad, the fan may be stuck in the on position and continue to blow air into your vents.
No matter what causes the problem, if your furnace never turns off, it is something you should have inspected right away. It doesn’t matter whether the furnace is producing heat or if the blower is simply moving air through the vents – it can cost you a bundle and every moment the device is left on puts more pressure on the components of your heating system.
On top of all that, there is a very real risk when electrical components are involved. A shorted wire or bad relay can make operation of your furnace dangerous. If a circuit breaker flips at any point, you should call a professional immediately because it is almost certainly an electrical issue and needs to be resolved before anything else happens.