Floor Heating Keeps Blowing A Fuse? 4 Possible Causes

Floor Heating Keeps Blowing A Fuse? 4 Possible Causes

Does your underfloor heating system blow a fuse every time you turn it on? Then find out 4 reasons why this happens and how to fix it in this article. 

If your floor heating keeps blowing a fuse, it may be because:

  1. There is not enough power
  2. The circuit is overloaded
  3. The flooring is broken
  4. The pump is faulty
  5. The heating isn’t turning off correctly

But how can you figure out what is wrong with your underfloor heating and most importantly, fix it? Take a look at the upcoming section of this article where we will walk you through fault finding and solving these problems.

Solving Floor Heating That’s Blowing A Fuse

There’s nothing more comforting in the cold months than the feel of the toasty floor beneath your feet. It’s the coziest way to warm up both you and your home.

But what if your heating system is up the creek? You turn it on and it runs for a few minutes. But before long the fuse blows. So, you change the fuse and then try again and the same thing happens. Now you’re feeling really frustrated. You’re sitting in the cold and you’ve blown a handful of fuses in a matter of minutes. 

Now, do not despair as help is on the way. Coming up next in this article, we are going to go through 4 reasons why your floor heating keeps blowing a fuse. Not only that, but we’ll also discuss a number of things that you can do to fix this problem. Let’s jump right to it. 

Reason #1 There Is Not Enough Power

Your underfloor heating system relies on a good supply of electrical power. The bigger the system, the more power you will need to keep it running. If your floor heating keeps blowing a fuse every time you turn it on, this could be because there is not enough electrical power to run the system. 

Your floor heating needs the following three things:

  • Enough electrical power
  • The right type of circuit breaker
  • The correct circuit breaker rating

If any of the specifications mentioned above are not right for your floor heating system, it will blow. Now how can you know whether your floor heating system is getting enough power or not? The best way is to have a look at your heating systems’ installation manual. This manual will contain information on the exact electrical specifications needed to run your system. 

You should compare the specifications in the manual with your circuit breaker. If your circuit breaker is not powerful enough for the system, you will need to upgrade it. You should hire an electrician to complete this job. 

Do you think that your floor heating already has enough electrical power to run correctly? Then you might have a faulty wiring issue. To fix this, you should have an electrician check out your heating. But before you do, have a look at the other common problems in this article that could save you the call-out charge.

Circuit Breaker
Your underfloor heating needs sufficient electrical power.

Reason #2 The Circuit Is Overloaded 

Does your underfloor heating blow a fuse as soon as it turns on? Then there may be a couple of factors to blame. Here are some of the most common that link back to your circuit breaker: 

  • Your heating system is on a shared circuit
  • You live in an older home
  • You are not using the right voltage

Is your underfloor heating system on a dedicated circuit or a shared circuit? If it is on a shared circuit and the fuses keep blowing when you turn the heating on, you could have a circuit overload. What is the cause of a circuit overload? This occurs when there are too many electrical devices connected to the breaker. 

To fix this problem, you can do the following:

  1. Place your heating system on a dedicated circuit. A dedicated circuit will supply your underfloor heating with all the power it needs. Dedicated circuits are always preferable for underfloor heating systems. 
  2. Make sure that your circuit breaker can handle the load of the underfloor heater. It should be able to support the amount of amperage that your heating system needs. You should do this if your home does not have enough space to put the system on a dedicated circuit. To check this, you should look at the amperage rating in your floor heater’s installation manual. To make any changes to your system, you should contact your electrician. 
  3. Use a relay when connecting multiple heaters to one thermostat. You may also need to install a larger circuit breaker. Only qualified professionals should tackle these jobs.

The electrics in older homes were not fitted to support our modern-day electrical needs. Because of this, using a floor heating system along with other electrical items might be too much for your system. To fix this problem, you should install a dedicated circuit for your floor heater. 

Not supplying your system with the right voltage will also make it blow a fuse. Some underfloor heating systems have dual voltage thermostats. But even still, you must ensure that you supply your system correctly. If you’re not sure of the specifications needed for your heater, you should check your installation manual. Alternatively, you can contact your electrician.

Hand Installing Circuit Breaker
You may need to install a dedicated circuit for your heating system.

Reason #3 The Flooring Is Broken 

Under the floor of your home rests an intricate heating mat that warms the tiles beneath your feet. Do you have any cracks in the tiles or panels of your flooring? If something heavy dropped on the floor it could have broken your panels or tiles. This, in turn, could have damaged the heating mat. This might be the cause of the fuse blowing constantly. 

What can you do to fix this problem? Here are a couple of steps that you can follow:

  1. Inspect the floor in your home for any cracked tiles or panels
  2. Lift the panels where cracks show to inspect the leveling compound below
  3. If the leveling compound shows signs of damage, you will need to contact your HVAC provider so that they can inspect the heating mat. They may need to remove more of the flooring to repair the heating mat and get the system running again.
Broken Floor
A heavy blow to the floor could damage your heating mat.

Reason #4 The Pump Is Faulty

There are many electrical components in your underfloor heating system that could develop a fault. One of the biggest culprits, however, is the pump. A faulty pump could cause your heating system to short and blow a fuse when you turn it on. 

If you suspect your pump is to blame, what can you do? Take a look at the following steps to find out:

  1. Isolate the electrical power to the pump. You should ensure that you turn off the main consumer switch too. 
  2. Disconnect the electrical wiring to the pump
  3. Turn the power back on to the underfloor heating system and test it. If it does not trip, the pump may be the flaw in the system. 
  4. Replace the faulty pump


If your floor heating keeps blowing a fuse before it has the chance to get up and running, there is an issue. But as we have seen in this article, there are 4 major reasons why this happens, and thankfully, they can all be fixed. I’m sure this article has helped you to identify why your floor heater blows a fuse and what you can do to solve the problem.

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Thanks for reading, and have a great day!



I've been helping homeowners with appliance repair since 2016. Starting out as an enthusiastic amateur, I've since worked with many Appliance, HVAC, and DIY experts over the last 7+ years. My mission is to help fix your appliances and prevent future issues - saving you stress, time, and money. Visit my author page to learn more! Read more