Radiant floor heating provides energy-efficient, consistent warmth, but like any heating system, it can develop issues over time. If your system has cold spots, fluctuating temperatures, or has stopped working altogether, don’t worry — many problems have simple fixes.
For electric systems, thermostat failures or damaged heating mats are common culprits, while hydronic systems often suffer from valve issues or airlocks. Some problems you can troubleshoot yourself, while others may require a professional. In this guide, we’ll walk you through the most common radiant heat problems, how to fix them, and when to call in an expert.
Troubleshooting Your Radiant Floor Heat System
If your radiant floor heat isn’t working properly, follow these steps to diagnose and fix the problem:
- Identify your system type. If you didn’t install the system yourself, determine whether it’s electric or hydronic. Electric systems use heating cables or mats, while hydronic systems circulate heated water through pipes. Knowing your system type will help you pinpoint potential issues.
- Check the thermostat. A faulty thermostat is one of the most common reasons for uneven or nonexistent heating. Verify that it’s set to the correct temperature and functioning properly. If it’s inaccurate or unresponsive, replacing it is usually a quick and affordable fix.
- Inspect valves (hydronic systems only). If you have a hydronic system, check the valves that regulate water flow. Make sure they’re fully open and set to the correct temperature. If a valve is stuck or malfunctioning, it can cause inconsistent heating.
- Look for air locks (hydronic systems only). Trapped air in the pipes can block water flow, preventing heat from reaching certain areas. If you hear gurgling noises or have cold spots, you may need to bleed the system to release trapped air.
- Call a professional if needed. If these steps don’t solve the issue, it’s best to call a heating specialist. Many HVAC professionals offer diagnostic services and DIY repair kits for minor fixes. For electrical issues or major component failures, professional help is essential.
Electric Radiant Heating Systems Common Issues
Symptoms: System won’t turn on, runs continuously, or heats unevenly.
Fix: Most broken thermostats cannot be repaired and must be replaced. A new thermostat typically costs $50–$200. Installation is straightforward if you’re comfortable handling electrical wiring. Otherwise, a professional can install it for $100–$300.
Symptoms: Certain areas of the floor stay cold.
Fix: Floor sensors can help detect damage, but repairs often require removing sections of flooring. If your system is still under warranty, contact the manufacturer. Otherwise, expect repair costs between $500 and $2,000, depending on the flooring type and severity of the damage.
Symptoms: The entire floor or patches of the floor stay cold.
Fix: Unless the issue with the mat lies in a single (or a few) faulty area(s), you must replace the entire mat. A repair person will remove the room’s flooring and replace the mat with a new one. You can try to do this yourself if you’re a handyperson. Otherwise, your local HVAC technician can complete the repair for you.
Hydronic Radiant Heating Systems Common Issues
Symptoms: Uneven heating, some rooms colder than others.
Fix: First, check the transformer — if a fuse is blown, replacing it (about $5–$20) may solve the issue. If the valve itself is stuck or faulty, a replacement costs $100–$300, plus labor if you hire a pro.
Symptoms: Persistent cold spots, visible leaks, or a sudden drop in heating performance.
Fix: Pipe repairs are complex and often require tearing up flooring. Costs range from $500 to $5,000, depending on the location and extent of the damage. Call a professional immediately to prevent further damage if you suspect a leak.
Symptoms: Gurgling noises, weak or no heat in certain areas.
Fix: Bleeding the system releases trapped air. Some systems have an automatic air vent, but if not, you may need to manually bleed the lines. If the issue persists, an HVAC technician can help for $100–$250.
