Get a fast and reliable fix for your furnace problems.
Every year homeowners in London, Ontario experience the cold Canadian winter. The temperature in Ontario can get as low as -73 °F. Having a reliable heating system in your house will make your life easier and your home a comfortable and warm place to live in during those months.
Having a broken furnace is not only bad for the durability of your house, but it also can be detrimental to your health and even lead to Carbon monoxide poisoning. We strongly believe that you shouldn’t try fixing the furnace yourself. Leave it to the certified experts, your safety depends on it.
Furnace repair experts at Plumbhouse have the training and expertise to conduct any type of furnace repair at your home any day and at any time. Call us today for a free furnace repair quote!


Why choose us?
Plumbhouse has been proudly serving London, Ontario for more than 15 years. We take our furnace repair service seriously; that’s why we provide the highest quality work, customer service and professionalism possible. We are transparent with our customers so they are sure what the problem is and how much it will cost them to fix it. Don't allow your furnace to break down when you need it the most. Our team is highly skilled and ready to help you!
Signs you need a furnace repair
- The furnace doesn’t turn on
- The furnace unexpectedly shuts down
- The furnace has difficulty sustaining temperatures
- You can smell a burnt electrical smell in the house
- Cooling turns on while the furnace is running
- The fan doesn’t turn off no matter what you do
- The furnace makes a lot of noise
- Rising utility costs
If your furnace is showing any of the signs above, or if it’s just acting weird and you’re worried about it, call us or fill the form for a free furnace evaluation. We’ll get to the root of the problem!
8 Common Furnace Problems
Furnace starts for a few seconds and then shuts down
Possible Problem Areas
- Dirty Flame Sensor
- Dirty Furnace Filter
- Bad Gas Valve
- Bad Ignitor
- Bad Ignition Module
- Dirty Pilot Assembly
Possible Explanation
- The flame sensor gets dirty with time and once there’s enough dirt on it, your furnace will stop sensing the flame.
- Every furnace has a heat limit. When the filter gets dirty, the amount of air getting inside reduces and the furnace inside gets too hot. That process starts an endless cycle: the heat limit trips and it turns the burners off; the fan leaves on, cooling the furnace until it is able to turn the burners back on.
- Your Gas Valve is broken and requires replacement. You should also check the gas, make sure you didn’t turn it off. If the problem is only with the gas supply, you will hear the gas valve opening.
- Sometimes the ignitor gets bad due to the materials and the length of use.
- Spark Ignitor is not sending the spark to the ignitor.It might also not be sending power to the gas valve.
- The intermittent pilot system has a little pilot hood, a spark igniter and a flame sensor. So what happens is it'll have a silver tube coming out of the gas valve, which is the pilot tube. That pilot tube opens up first, let's put gas into the pilot to light that pilot intermittently, or basically when there's a call for heat, so that little pilot lights and once the flame sensor proves that there's a little flame there. Then that will tell the gas valve to open up and light all the burners. And what happens is that little pilot tube that goes to the pilot hood, there's a little orifice in there, which is really tiny. If some stuff falls on that little pilot orifice that will plug it up and your pilot flame will not be hitting that flame sensor as well as it should be.
Possible Solution
- Clean the flame sensor
- Replace the filter
- Replace that Gas Valve
- Replace the ignitor
- Replace the ignition module
- Clean the orifice
The furnace doesn’t keep up. Especially when it’s cold outside
Possible Problem Areas
- Dirty Furnace Filter
Possible Explanation
- Every furnace has a heat limit. When the filter gets dirty, the amount of air getting inside reduces and the furnace inside gets too hot. That process starts an endless cycle: the heat limit trips and it turns the burners off; the fan leaves on, cooling the furnace until it is able to turn the burners back on. This cycle wastes a lot of energy and makes it more difficult for the furnace to heat your house.
Possible Solution
- Replace the filter
The furnace isn’t working at all
Possible Problem Areas
- Bad Inducer Motor
- Bad Control Board
- Bad Heat Exchanger
Possible Explanation
- Sometimes something might get stuck in the motor, which will prevent it from working properly. The motor might just get broken because of the long use or the bad materials used for its production. You should also check if the motor is getting the electricity from the board, it might be the problem with the board and not with the motor.
- The power does not get to the control board. The part of the control board got damaged and it prevents it from giving the power to the parts of the furnace.
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Heat Exchanger separates the exhaust and the air in your house. The tubes in the exchanger crack with time, the average time is 15 years.
Factors that reduce heat exchanger’s length of service:
- Overheating due to the constant use of a dirty filter
- Plugged coil
- Bad ductwork
- The furnace was installed poorly, to begin with
Possible Solution
- Replace the Inducer Motor
- Replace the control board
- If there's a crack or a hole in your heat exchanger, the heat exchanger or the whole furnace must be replaced.
You can smell a burnt electrical smell in the house
Possible Problem Areas
- Bad Blower Motor
Possible Explanation
- You didn’t replace the air filter in time, or there was an electrical surge, or the capacitor that gives the fan a boost is dead.
Possible Solution
- Replace the blower motor and capacitor if the wheel is bad
The fan starts very sluggish and then completely quits
Possible Problem Areas
- Bad Blower Motor
- Noisy Blower Motor
Possible Explanation
- You didn’t replace the air filter in time, or there was an electrical surge, or the capacitor that gives the fan a boost is dead.
- The blower wheel is out of balance, or some of the fins are broken off.
Possible Solution
- Replace the blower motor and capacitor if the wheel is bad
- Replace the blower motor, the wheel and the capacitor.
The fan doesn’t turn off no matter what you do
Possible Problem Areas
- Bad Control Board
- Bad Thermostat
- Hi-Limit Switch Stuck Open
Possible Explanation
- The power does not get to the control board, or the part of the control board got damaged and it prevents it from giving the power to the parts of the furnace.
- The thermostat is broken or not working properly.
- If you have a dirty filter for a while and your high limit keeps tripping over and over again, the limit switch, that is made of 2 different metals, when heats up, one of the metals warps and disconnects, which interrupts the circuit. If that keeps happening multiple times, that switch will get stuck open.
Possible Solution
- Replace the control board
- Replace the thermostat
- Take the limit out and give it a few knocks. A lot of times that will be enough to free it up. If nothing frees it up, then you just have to replace the limit.
The furnace is overheating and tripping on a high limit
Possible Problem Areas
- Plugged A-Coil
Possible Explanation
- After a while, especially if you don’t change your air filter in time, or you have a bad filter, all the dust will settle on the underside of the coil and plug it up, causing a restriction in the airflow. The heat starts to build up in the furnace and trips the high limit.
Possible Solution
- Clean your A-Coil
The furnace is showing a "pressure" code error
Possible Problem Areas
- Plugged Condensate Trap
Possible Explanation
- Plugged up water condensate trap is causing water to back up in your collector box and your pressure switch hoe is generally hooked right to that collector box. So if it senses that there is water in there, it will shut the furnace off.
Possible Solution
- Clean the hose with hot water and put it back in