If your furnace is turning on and off erratically, first check that it’s actually getting power. Oftentimes the power switch to your furnace will get flipped off accidentally, which means that the unit won’t be able to ignite gas.
Luckily, most furnace problems can be fixed on your own! However, some issues require the help of a professional. Discover more at Coquitlam furnace repair.
1. Pilot Light Issues
While advancements in furnace systems have moved away from traditional pilot lights and more toward electric ignition, many older furnaces still use a pilot light. In those systems, the pilot flame can go out for a variety of reasons.
One common reason is a dirty pilot orifice. This occurs when soot, carbon, and other debris clog the small opening where the pilot flame burns.
Another cause is a faulty thermocouple (also called a flame sensor). Located near the pilot light, the thermocouple detects whether the pilot flame is lit or not and, based on this information, controls the gas valve. If the thermocouple is covered in soot or otherwise displaced or damaged, it will fail to turn on the gas valve.
If you suspect your pilot light is going out frequently, consult your system’s manual for instructions on relighting the pilot light. You may also want to call a professional to inspect and repair the system.
2. Thermostat Issues
If the thermostat seems to be displaying heat, but the furnace fails to start up or turns off after a few minutes, it could mean that the heating system itself is not getting power. Generally, the circuit breaker will need to be flipped to the on position. If it keeps flipping off, it’s a sign that there is an electrical problem and you should consult with a professional.
Other times, the problem can be as simple as a dirty air filter, which restricts airflow and causes the furnace to work harder. If this is the case, replacing the filter should fix the problem. A stuck damper is another possibility, though this is a more difficult issue to resolve and requires a professional. Other issues with the thermostat can cause inaccurate temperature settings, which also affect the performance of your furnace.
3. Clogged or Dirty Air Filters
Furnace air filters catch pollutants and debris, allowing for even heat distribution throughout the home. Changing furnace air filters on a regular basis is one of the easiest and most inexpensive ways to support a heating system.
A dirty filter limits airflow and forces the blower to work harder. This can cause it to overheat and strain critical components, such as the heat exchanger or burners.
Symptoms of this issue include an inability to ignite the flame, which can be caused by problems with the flame sensor rod or a malfunctioning high limit switch. A trained professional should be called to diagnose and repair the problem.
A dirty filter may also trigger the blower to cycle on and off frequently. This puts unnecessary stress on the system and shortens its lifespan.
4. Circuit Board Issues
When all is well, your home’s furnace quietly, efficiently keeps the indoor temperature at a comfortable level. But sometimes, it needs some help from you to get the job done. This often takes the form of a tripped circuit breaker, unresponsive controls, or inconsistent heating and cooling throughout your living spaces.
If your breaker trips repeatedly, check the voltage meter at the control board’s terminal strip. You should see a reading of 24 volts. Also look for signs of moisture damage on the control board’s back side. These might include hairline fractures of traces or discolored solder joints. Other issues that might affect a control board include a failed transformer or failing transistors. Stuck switches can also cause problems. These are often caused by dirt, loss of a protective coating, or warping.
5. Water Leaks
A leaking furnace is something no homeowner wants to deal with, especially during cold weather. It’s a sign of a problem that could lead to water damage in the home, so it should be addressed right away.
There are many reasons why your furnace could leak water. The most common is a blocked or clogged drain line. This is an external hose that connects the furnace to the drain trap and guides excess water into the floor drain. It can get clogged with grime over time, which is why routine maintenance and cleaning are so important.
Other potential causes include thermostat issues, motorized valves, airlocks, and diaphragms. All of these issues require a qualified technician to fix them safely and effectively. Detecting and fixing these problems early will save you time, money and stress in the long run.
