Common Problems Associated With In-Floor Radiant Heating Systems

An increasing number of people are embracing radiant floor heating systems.  The advantages make the reasons for this popularity clear. In-floor radiant heating systems allow for a comfortable and consistent heating of the whole room requiring far much lower energy levels compared to the traditional HVAC systems. The floor is so comfortable you can walk bare feet even in cold weather. You also have the advantage of zonal heating. This means you can heat only the rooms that are being used further reducing the amount of heat spent to earn you comfort. Other benefits include low maintenance costs, longer operating life and the elimination of duct systems and annoying wall radiators.

However, some problems might arise in the course of the working of the heating systems which require urgent repairs. Some problems are straightforward while others may involve a number of parts in the system. Getting a certified expert to fix it is the right way to go. The repairs are also easy since the system can be easily accessed once the problem’s location has been identified. While some repairs and problems are common others depend on the type of radiant heating system. There are two kinds of in-floor heating systems that use radiation; one uses electricity as the heating option while the other, hydronic relies on either hot water or steam for heating. This makes the problems and approach to the repairs different.


  • Tripping circuit breakers: Electric radiant heating does not require lots of electrical power; however, it is important depending on your usage and scale of house to have enough electrical power in the box to support the system and prevent tripping the circuit breaker. The average amperage is 200 amps for the modern home electrical panels. If your box does not support such an amount you will need to upgrade it prior to installation.
  • Damages to the electric mat or the cables: The cables and the electrically conducive mat are made to be durable and long lasting. Further, their placement under the floor ensures they are not exposed to lots of damage risks. However, cracked tiles, heavier objects or home renovation may end up causing damage to them and necessitating repairs. In such cases the repairs have to be done soonest for safety and convenience reasons.


The hydronic radiant systems also have a couple of common problems. In this system a boiler is needed as the source of heat. Some of the problems you may encounter include:

  • Zone valves or circulator pumps problems: Zone valves and circulator pumps are used to push the hot water from the boiler into the whole piping. Should they break or bend, they will affect the quality of heating in your home with lesser amount of water getting to be circulated in the piping.
  • Air lock issues: The boiler system is a pressurized environment and sometimes air bubbles can be formed in the pipes. Sometimes these air bubbles can act as a blockage preventing the flow of hot water by creating an air lock.


Whether you are using a hot water radiant in-floor heating system that produces heat by passing hot water through a coil or an electrical radiant in-floor heating that uses heating cables, learning how to troubleshoot your system is important. In this post, we will be looking at some of the most important things you need to do to troubleshoot your radiant floor heating.

  • Wall thermostat

The main cause of problems with in-floor radiant heating systems is a defect in the wall thermostat. When your thermostat is defective, it will keep the heating from working properly. Thermostats that fail to close properly cause the room to be cold at all times. The best thing is that it is quite easy to inspect and replace defective thermostats.

The first thing you need to do when troubleshooting your thermostat is to check if there is voltage getting to it. You can do this using a noncontact voltage tester. If you detect no voltage, there is a good chance you have tripped the circuit breaker or a fuse might be blown. Start by resetting the circuit breaker or replacing the blown fuse. Recheck for power. If you still get no power, check the voltage at the zone valve if you are using a hydronic radiant system. For the electric system, check at the splice box. Always turn off the circuit breaker before you start replacing the thermostat. Get the cover off from the thermostat, remove the wiring by loosening the screws then slip the wires out. Remove your old thermostat and take it with you to get an exact replacement.

  • Replace the defective zone valve

To do this, you must start by switching off the circuit breaker. Disconnect the wires and then turn off the zone valve to disconnect the water supply. You also have to open the drain valve so as to drain out water from the heating coil. Thereafter you need to unsolder your old valve from the copper pipe supply and hot water and pipe leading to the heating coil. Don’t forget to carry your old valve to the home center so as to get an exact replacement.

  • Replace defective heating mat or cable

Heating mats or cables are located beneath a rough flooring or between subfloor and the finished flooring. You need to remove the top floor in order to gain access to the heating mat or cable. You can then determine which part needs to be replaced by taking readings of each section using a digital multi-meter. Set the multi-meter to the Ohms range. Don’t forget to carry the set of old cables/mats with you so as to get the exact replacement.

  • Room not getting warm enough

If your room doesn’t heat sufficiently, there is a chance your thermostat opens sooner than it should or zone valve doesn’t open up fully. There is also a chance that your heating mats or cables are defective. To test if the issue is with the thermostat, bypass it with jumper wires. For the zone valves, you can disassemble and clean them so that they open well. Defective sections of heating cables need to be separated section by section to determine continuity in every section.