6 Things To Check When Your Furnace Isn’t Working

It seems to be inevitable that you come home to find your furnace has stopped working on the coldest day of the year. Before you call a professional for help there are a few things that you can check on your own that might solve the problem and save you from having to pay for a service call.

Start with the thermostat

These days many of the thermostats installed in our homes require batteries. While it may seem obvious people often don’t think to change the batteries in their thermostat when they have no heat. This should be your first step as it is an easy fix.

How often do you change your filter?

They say you should change your furnace filter every three months, now if you’re like me you forget and sometimes the filter goes unchanged for six months or longer. This is another easy fix remove your filter and take a look at it. If it’s clogged with dirt, hair and other debris or you can not see any light through it, it is time for a new filter. Note the size go to the hardware store a get a new filter.

Is your filter too good?

Another filter related issue that I have run into is the high-density, allergen blocking filters with a high MERV rating can sometimes restrict the air flow through your heating system causing your furnace to shut down even if the filter is clean. If you have recently changed your filter to one of these high rated filters and your furnace stops working this could be your issue try a less expensive filter and see what happens.

Can your furnace breath?

Many of today’s high efficiency furnaces have intake and exhaust venting that exits the exterior wall of your house close to ground level.  If there has recently been a large snow fall or if there have been high winds with blowing snow you should check the venting outside your home.  If you look at the exterior of your home near where your furnace is located you will see black or white plastic piping that sticks out from the side of the house. This is the venting for your furnace, and possibly your hot water tank, if these pipes are blocked your furnace will not have sufficient air flow and will shut itself down. Make sure that you clear any snow away form the venting and check inside the pipes to ensure there is no visible blockages from snow getting packed in them.

Look for the error code

If you have checked all of the above before you try to restart the furnace you should look for an error code. Newer furnaces have a little round window in the front panel and if you look inside you should be able to see a blinking light. Each manufacturer is different but count the number of times the light flashes.  Once you have counted the flashes refer to the owners manual for the furnace and that should tell you what the problem is. If you don’t know where the manual is, not a problem you can usually google error codes and the make and model of your furnace and get the answer there.

You might not be able to do anything to resolve the problem but with this information you can inform the repair company of what is going on and it could save you some time or money if they know before they show up what the likely cause of the problem is.

Restart the Furnace

One more thing you should try before you call the repair company is to turn the furnace off and back on again. With most furnaces there will be a light switch that is close to the furnace likely in the basement ceiling where you can turn the switch off and back on again. It is often a good idea when restarting the furnace if it hasn’t been working to adjust the thermostat to a temperature below the current temperature in the house so there is not a call for heat immediately upon restarting then adjusting the thermostat back to your desired temperature. Like many devices that have an electronic component, sometimes restarting your furnace will solve the problem.

Call for Help

If your furnace still is not turning on it is probably best to call a certified repair company to come and resolve the issue. Make sure that if you have taken the time to check the error code you advise the repair company of the code, as they might be able to walk you through a simple fix over the phone or at least know what type of issue they will be dealing with when they arrive to your home.