10 Common Wall Mounted Gas Heater Problems & How To Fix Them

When you encounter wall-mounted gas heater problems, it’s important to find the right advice or seek assistance from a professional. This is mainly because a faulty gas heater is dangerous and can cause severe health problems. Luckily, there are various ways you can fix the issue, but you have to ensure you follow the right tips we’ll outline in this post. 

Here are 10 common wall mounted gas heater problems:

  1. The gas wall heater keeps shutting off
  2. The gas wall heater won’t turn on
  3. The Wall heater pilot won’t light
  4. Wall heater thermostat not working
  5. The gas heater keeps going out
  6. Wall heater gas control valve problems
  7. Carbon monoxide and moisture issues
  8. Inefficiency if it’s unvented
  9. Risk of fire
  10. Old heaters becoming dangerous

The rest of the article will focus on what’s causing these problems and how you can fix them, and other troubleshooting tips. Keep reading to learn more.

1. Why does my gas wall heater keep shutting off

If your gas wall heater keeps shutting off, it’s because of low airflow. One of the reasons that you have low airflow is dirty air filters. If you don’t clean or replace your air filters regularly, the filters attract dirt and become clogged; hence the heat exchanger retains heat and eventually causes it to overheat.

2. Gas Wall Heater Won’t Turn On

If your gas wall heater is not turning on at all, check to make sure that the switch is ON. Check for a tripped breaker or blown fuse if the switch is ON. Reset the breaker or replace the blown fuse, if necessary. If the problem isn’t with the breaker box, examine the unit’s wiring for loose connections. If you still can’t get the heater working again, it probably needs a new heating element.

When a gas wall heater doesn’t turn on, there is a high possibility that it’s an issue with the pilot light. These heaters tend to work similarly to the way gas water heaters do. Therefore, if the pilot is not lighting, then the first thing you need to do is check the gas supply to the heater. If your heater uses propane to run, the tank might be empty.

The pilot typically burns constantly and ignites the burner when the temperature falls below a specific point. But, some usually use an electric igniter, which uses a spark to ignite the burner, similar to most gas ovens.

But, if the heater runs on natural gas, you need to check and ensure the gas is turned on through the valve handle on the gas line. If the gas happens to be flowing but the pilot still isn’t lighting, then the pilot tube might be blocked.

You need to reach into the combustion chamber and clear the tube with a bit of compressed air. The next step is to turn off the gas and wait for 10 minutes for any gas in the combustion chamber to dissipate before attempting to relight the pilot again.

3. Wall Heater Pilot Won’t Light

If the wall heater pilot isn’t lighting, the issue might be due to a blockage in the pilot tube. If you’re experiencing this issue, you need to first turn off the gas, clear the tube with a bit of compressed air, and then try to relight the pilot.

If the wall heater pilot still won’t light, the best option is to call a professional technician to come and look into the issue. It’s important to note that the repairman may need to replace the thermocouple with a new one. 

Wall heaters are pretty reliable, but sometimes they can also experience problems like any other appliances in your home. When that happens, it’s important to seek professional advice or assistance. This will help you avoid causing more damage if you don’t know how to fix the issue.

4. Wall Heater Thermostat Not Working

If you’re having problems with the heater thermostat, it can cause the heater to malfunction. In this case, it may also result in faulty components incurring more repair costs.

If you see that your heater thermostat is not working at all, the first thing you need to check is if it has a tripped breaker or blown a fuse. If it has a blown or tripped breaker, you can reset the breaker or replace the blown fuse.

But, a replacement has to be done if it’s only necessary. If you feel like the tripped breaker can still function, there is no need to replace it. You can also remove the heater control knob, thermostat knob, and faceplate to check loose connections in the mechanisms.

If the wires are loose, ensure you tighten them properly. This will help get the thermostat working again. But, if it doesn’t, then you need to seek professional help.

5. Gas Heater Keeps Going Out

If you happen to have a furnace pilot light that keeps going out, then there is a high possibility the thermocouple may be broken. The thermocouple is a rod that comes into physical contact with the flame in your system.

This component deactivates the gas when the pilot light goes out. You also need to know that several instances may cause the thermocouple not to detect the flame in your gas furnace. 

When the component can’t detect the flame, it will close the gas valve and prevent a gas leak in your home. Some of the issues that may cause the furnace pilot light to keep going out include:

  • Dirt buildup on the thermocouple – As the gas furnace ages, dirt and grime tend to form on the thermocouple of your system. When this smooth layer becomes too thick, it prevents the thermocouple from coming into direct contact with the flame. When that happens, it’s recommended to detach the thermocouple from the furnace and clean it to remove dirt. But, if cleaning detaching doesn’t solve the problem, the other solution would be to replace the component with a new one.
  • The thermocouple may be deformed – Another reason is that the thermocouple in your gas furnace may be bent or deformed if it’s too old. The deformity may cause a small portion of the thermocouple to be prevented from coming into contact with the flame. Therefore, this is a common cause of pilot light deactivation problems. 

6. Wall Heater Gas Control Valve Problems

If you have valve problems in your wall heater gas control, it’s important to try and find ways to solve them. A wall heater gas valve is one of the many components that can fail.

Therefore, before you decide to replace the valve, it’s essential to conduct some basic troubleshooting to find out the root cause of the problem.

Before troubleshooting, turn the gas valve to the “pilot” setting and turn off the water to the heater. Doing that makes it safe for you to troubleshoot and find out the issue. But if your unit isn’t producing any hot water, you need to check the pilot flame.

If it’s functioning properly, then it could be the valve. If you find out that the gas control valve is the one with the problem, I highly recommend hiring a professional to come and fix the issue.

7. Carbon Monoxide and Moisture Issues

Carbon monoxide is one of the most dangerous gases. The worst thing is that you can’t detect its odor, color, or taste. Therefore, this means that dangerous gas concentrations can quickly build up in your house and cause serious health problems.

Some of the common causes of carbon monoxide are fuel-burning appliances in your home, such as wood stoves, water heaters, furnaces, and boilers, among many others.

To properly deal with carbon monoxide and moisture issues, you need to vent your home appropriately and maintain fuel-burning appliances. This means that you need to keep doors open throughout your house. You also need to open windows to allow fresh air inside. Additionally, avoid using appliances meant for outdoor use inside your house. 

Installing and maintaining carbon monoxide alarms in your home is another good solution. Some states, such as Minnesota, require every home to have one operational carbon monoxide alarm. This helps to prevent any severe problems that CO might cause in your home.

8. Unvented Gas Wall Heaters Are Inefficient

Unvented gas heaters can be quite dangerous. These types of gas wall heaters are not a good idea, although they are the most popular. Another thing that makes unvented gas wall heaters inefficient is that installation is cheap and easy. You need to buy the unit and hook it up to your gas supply.

You can develop severe allergies and burning watery eyes with unvented gas wall heaters. These issues can escalate and result in more problems. This is why it’s important to consider using vented gas wall heaters because they are safe and efficient.

9. Risk of Fire

Fire risks usually come from appliances or carbon monoxide leakage in a home. When home appliances are not well maintained, they may break up and cause fire outbreaks.

This is why properly maintaining wall heaters is essential if you want your home to be safe. You also need to have a way to detect carbon monoxide leakage in your home to counter any issues that result from a high concentration of gas in your space.

To prevent fire risk, make sure you have a fire alarm in your home. Another thing you need to do is to strictly make sure the appliances you’re using in your home are specifically designed for indoor use and not outdoor use.

10. Older Models Can Be Dangerous

Older gas wall heater models can be dangerous. This is because some parts may be broken and result in fire outbreaks. Simply put, older models are not stable and reliable.

Therefore, it’s highly recommended to avoid wall heaters that are too old and use new ones. If you have an old wall heater, it’s essential to call a professional to look into it and ensure it’s safe and reliable to use in your home.


The above wall-mounted gas heater problems we’ve discussed in this post are just some of the few common ones. There are also other issues that you need to be aware of, and conducting more research will help you learn how to fix them or prevent them from occurring.

I hope this post has helped you learn ideal ways to stay safe in your home. But, if you have any questions, feel free to reach out through email, and I’ll be happy to help.