Red radiant floor heating pipes set out in preparation for floor to be poured.

Radiant floor heating has become a go-to option to keep your toes and your home warm and cozy.

Now while they are durable and work seamlessly for many homeowners, ignoring repair and maintenance issues for too long can lead to the system facing functional problems.

So, what are these issues?

There are around nine notable problems with a radiant heating system, especially if it has a faulty installation. These problems hinder the system’s performance and raise your electric bills. But if you know the system’s components and their functions, it can help you detect the defects.

Keeping this in mind, let’s check these faults and understand their impact on your radiant in-floor heating.

We will go through electrical and manual faults that you might find in a radiant floor heating setup.

Let’s get going.

1. The Cables Look Damaged

Damaged electrical cables with the insulation worn through exposing the wire inside.
Damaged cables can be a cause of your system not working and can also cause fire.

Damaged cables are often the result of faulty installation. If the contractors are not careful enough, they might drop something over the pipes or handle them without sufficient care.

In a radiant floor heating system, you will find these cables:

  • Under the rough flooring.
  • Between the finished floor and the subfloor.

Since the cables stay protected under your flooring and are fragile, you must be careful while inspecting any damage.

This damage can also occur due to floor drilling. If you had to have your floor drilled for any surface installation, the driller might have accidentally damaged the underground cables.

In such situations, you must take prompt action since broken, damaged, or otherwise faulty electrical cables are a fire hazard and can put your home and its inhabitants in danger.

We suggest always using a professional HVAC technician’s help to assess and fix such matters if you are not knowledgeable about electrical fixes.

It can help you stay safe and get your radiant floor heating back to normal in no time.

For information about how much electricity a radiant floor heating system can use, read our article on the subject here.

2. The Floor Is Not Warming Up Properly

Is your floor not warming up enough even though the radiant floor heater is on?

If this happens, it could be because your heating mat is defective. These mats are expensive and are built to last a long time, helping you make a safe long-term investment.

However, you need a professional HVAC technician to help with this, as the frayed wires inside can lead to fire and electrical hazards.

It’s best to opt for replacing these mats instead of repairing them because it can help you avoid unnecessary re-repair expenses.

Make sure to find the best heating mats for your next floor installation. Of course, if it is a minor fault that can be fixed, you can opt to repair it instead.

3. Your Circulating Pump Is Not Working

Technician looking at a broken pump in heating system.
If your pump is broken, you’ll probably need to call out a professional.

While electric radiant floor heating uses mats, hydronic radiant heating systems work by using a water heater.

These water heaters have many components, such as:

Due to this, if this heater stops working, the entire pump will stop working and it becomes silent, which is a sign that your radiant floor heater is not working anymore.

So you can have the thermostat set to a warm temperature for comfort but not feel any heat due to this malfunction.

Now, there are two types of pumps for hydronic radiant heating systems:

  • Single pump that distributes water to all parts of the system.
  • Multiple pumps that circulate water to their designated zones within a heating system.

You need to be a professional plumber or have sufficient knowledge about radiant heaters to fix this issue yourself.

Although, we would advise you to call professionals so that you get seamless repairs and replacements for your faulty radiant floor heaters.

4. Your Radiant Heater’s Thermostat Is Broken

The line-voltage thermostats for radiant floor heaters have full circuit voltage.

If the thermostats stop working, you will need to find a replacement. If you don’t, it will either stop working entirely or work overtime, putting a major hit on your electricity bill.

While it is a crucial component of your heater, the thermostat is the easiest to fix.

Now, a faulty thermostat is not too dangerous. You will need a non-contact voltage tester that can alert you through lights and sound changes.

They are safe to use and come with numerous features like sound and light alarms that help you stay safe and alert to any dangers. You can use it to detect how much voltage is present in the thermostat.

Here is the step-by-step method of determining the voltage in your thermostat:

  • If your thermostat voltage tester shows no voltage, reset the breaker or replace the fuse on the control panel.
  • If the tester shows some voltage, check the electrical system using the voltage tester.
  • If this location shows no power, then your thermostat is broken.

5. You Detect Leakage

Closeup of a pipe that has sprung a leak and is causing water to spray out.
If your radiant floor heating pipe springs a leak, you could be in for a hefty repair bill.

A radiant floor heating system heats your floors by using hot water tubes. These tubes heat the heating zone by taking water from the boiler and circulating it around.

Now, these tubes underground might have some leaks forming due to:

  • Incorrect installation
  • Puncture caused during the floor installation.

You will find water seepage on the floor due to pipe leakage, which might deteriorate your flooring and cause a mess.

Fortunately, repairs are possible. But it might take a while, especially since professionals in radiant flooring will need to:

  • Remove the flooring above the punctured pipes.
  • Cut out the pierced pipe section.
  • Replace this section with proper tubes for steady water flow.

We advise you not to try repairing the pipe leakage by yourself. It will be much better to call professionals since it is a time-consuming and hefty job, requiring a lot of experience and plumbing knowledge. 

6. Damage in the Zone Valves

Zone valves in under-floor heating systems are in charge of managing water flow through the tubing. These valves help convey water from the boiler to the heating system.

Now, any type of bend or break in the valve can impact the water circulation and the radiant floor heating and damage your system in the long run.

These malfunctions occur due to poor installation techniques and wear and tear (through poor maintenance.)

While this issue is not too risky, damage to the zone valves will prevent the system from operating correctly and make it work overtime, resulting in higher energy bills and increasing the likelihood of breakdown.

In such cases, we suggest you call a professional to identify the problem areas and fix the damaged areas.

7. Tripped-Out Circuit Breaker

View of a row of breakers on a circuit breaker panel.
If your circuit breakers keep tripping out, you should call for a qualified professional to investigate.

If your circuit breaker trips out too frequently, your power requirements could be too high and the electrical box might not hold enough power for the radiant floor heating to function correctly.

Therefore, it cannot support the system and repeatedly shuts off, causing a frequent interruption in the underground heating.

Your radiant floor heating system installer will give you an instructional manual after the installation. As a homeowner, it is best to learn about your system and to stay alert to any problems.

In the manual, you will find the correct way to assess faults. The instruction and installation manual states the exact amount of electrical power your radiant heating system needs to run.

Armed with this knowledge, you, or your contractor, can ensure the wiring is fitted so you’re your heating system does not trip out.

The manual can also help you check if the wiring is faulty. If it is, call a professional electrician to prevent potential hazards.

8. The Pipes Are Damaged and Rusty

Proper maintenance can make any appliance last longer, especially your pipes.

Since pipes are an integral part of the radiant floor heating system, they can erode and corrode fast, which heavily impacts the heating system’s ability to function properly.

Although modern materials used for tubing are not susceptible to rust, on old systems, it’s possible that rusty pipes will make the heating less constant and cause water damage to your flooring.

Damage to the floor heating pipes can also be due to incorrect plumbing, especially if there is any type of dent in the pipes. In such situations, it’s best to call a professional who can remove the flooring and repair and fix the pipes.

Pipe repairs are one of the most expensive repairs to do. Fortunately, someone well-versed in radiant floor heating will ensure that your repairs are long-lasting and worth the investment.

9. Air Lock, Preventing Pipe Flow

Air locks are a common issue, especially with hydronic water underfloor heating and can cause damage to valves.

These occur in hydronic radiant floor heating systems and block the water flow between the heating coil and the boiler. Due to this blockage, the water does not heat properly to warm your room.

An air lock can cause your heating system to malfunction, but a professional can assess the damage quickly and get your system back up and running again.


There are many ways that radiant floor heating can go wrong.

Thankfully, because the pipework is protected under the floor, damage due to wear and tear from everyday activities is unlikely.

This is a double-edged sword, however, because if there is a problem, the concealed nature of the system can make troubleshooting difficult.

Most issues require a professional to investigate, but make sure you’re aware of what to look out for so you can quickly identify any faults before they cause serious damage.

To learn more about the pros and cons of radiant floor heating, please read our article entitled, “Hydronic Radiant Floor Heating Pros and Cons (Worth It?)“, which goes into detail on this topic.

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