Wondering why your furnace keeps shutting off and whether that’s normal? To start with your second question, it’s normal for a gas furnace to cycle on and off a few times every hour. It will vary by the type of furnace, but around 3-8 times is typical, anything more is a problem.
In answer to the first question — WHY your furnace keeps shutting off — look at these troubleshooting tips. They tell you how to diagnose the issue and how to fix it.
1. Inadequate Air Flow
In order to give off a nice steady supply of heat in our frosty Ottawa winters, your furnace needs good air circulation. Otherwise, your emergency shutdown feature will trigger, due to the heat exchanger overheating. Two simple DIY fixes could remedy this situation:
Change (Or Clean) Your Filter
Checking the air filter is always a good place to start when you experience furnace-related problems. It needs to be changed (or cleaned, if you use a permanent filter) at least every 3 months, and possibly as often as once a month.
A clogged air filter is simple to recognize – it will be full of dust, pet hair, and/or other assorted gunk. All that stuff is what blocks air from reaching your furnace’s heat exchanger.
Open A Few Air Vents
When a room in your home gets too hot, you probably close the air vents to cut down on the heat. That’s understandable, but please leave at least a few vents open. Once again, this allows the air flow that your furnace needs to keep on keeping on.
2. Your Thermostat Is Causing The Problem
If your furnace keeps shutting off even after you’ve made sure it has the airflow required, look at the thermostat. There are a few troubleshoots to try here:
Make Sure Thermostat’s Set Correctly. Check that your thermostat is on and set at “heat.” Ensure that the temperature setting is correct, as well. Too low a temperature could cause a furnace that keeps shutting off.
Find Out If The Thermostat Is Communicating Properly With Your Furnace. Turn your thermostat from low to high while someone else stands next to the furnace. Your partner should hear a sound that indicates the thermostat is communicating (in which case the malfunction is probably based in your furnace, not the thermostat).
Rethink Your Thermostat Placement. A thermostat that is located too near a heat source such as your stove or even direct sunlight is likely to register the higher temperature (even if the rest of the room is chilly) and switch the furnace off.
3. Your Flame Sensor Is The Culprit
Your gas furnace is equipped with a safety device called a flame sensor. When this sensor doesn’t detect any flames, it will automatically switch off the gas valve feeding the furnace, to protect your home against a natural gas leak.
With time, the flame sensor can corrode or grow covered with soot, which interferes with its function and causes it to close the gas valve unnecessarily. This is a problem that calls for professional furnace repair.
4. Your Furnace Is Oversized
Unfortunately, you may have been sold a furnace that is just too big for your house. As a result, it reaches your temperature setting too quickly — so the thermostat shuts it off. Then your home cools down, causing the furnace to start up again. This pattern of short cycling is inefficient and hard on your furnace. It won’t keep you very warm, either.
Consider shopping for a new, energy-efficient furnace that is the right size.
Heat Your Home Reliably
To fix a furnace that keeps shutting off, contact Ottawa Home Services. We provide reliable, professional gas furnace repair and replacement in the Ottawa area.