Although the furnace has the burners that actually heats up the house, it is the thermostat that tells the furnace how much heat is needed and when it is needed. A thermostat issue, therefore, can throw your furnace operations off the rails even if the furnace itself has no problem. Below are some of the common thermostat problems and how they affect heating.
Thermostats typically draw their power from the furnace, and the power comes from the mains supply. However, digital or programmable thermostats have batteries for power backup. The batteries supply the thermostat with power if there is a blackout. The backup batteries, thus, ensures that the thermostat doesn't lose its settings even if the mains power is off.
Dead thermostat batteries can interfere with the operations of your furnace. If the power goes off and the batteries are dead, then the thermostat may lose its settings and your house won't be at the temperature you want.
The thermostat works on the principle that metal expands when heated and contracts when cooled. The thermostat has a metal coil that expands and contracts to complete and break a circuit as needed. The metal coil completes the circuit when it makes contact with another conductor.
In some cases, however, the contact gets dirty and keeps the circuit open at all times. The accumulated debris — or built-up rust — acts as an insulator between the contact and the coil. You may have to clean the thermostat or replace it to get it working again; the solution depends on the cause of the insulation.
A thermostat is connected to the rest of the furnace via electrical wires. This method is how the thermostat gets its power and also sends its signals to the furnace. A problem with the continuity of the wires, therefore, interferes with the flow of electricity and signals between the furnace and the thermostat.
Loose wires, disconnected wires, or pinched wires are some of the problems that can interfere with the flow of signals and electricity between the furnace and the thermostat. In the case of loose, disconnected, or damaged wires, a qualified person can tighten or replace the wires as the situation calls for.
Where you place your thermostat also determines how well it plays its role. Ideally, the thermostat should be somewhere it can read an accurate temperature of the room. Such a location is necessary so that the thermostat can send accurate signals to the furnace and the furnace can make the necessary adjustments.
An example of a poor thermostat location is the area directly below a skylight. In such a place, sunlight and heat from above will heat the thermostat and give it a false reading. Your house may then feel cooler than it should because the thermostat and furnace will act on the false reading. The only solution in this situation is to move the thermostat.
Heat Anticipator Maladjustment
Lastly, the thermostat may also interfere with your heating if the heat anticipator is maladjusted. The heat anticipator is the brain of the thermostat; it controls the furnace cycles so the thermostat may stay on or off indefinitely if the heat anticipator has failed.
Digital thermostats have integrated heat anticipators that don't require manual adjustments. However, heat anticipators for mechanical thermostats require manual adjustment if something throws them off.
At Precision Heating & Cooling, we understand all about thermostats and general heating problems. Whether it is your thermostat or furnace that needs service, we have the expertise and tools to diagnose and solve your heating problem. Don't hesitate to contact us if your furnace has issues.