Propane Heater Shuts off After 5 Minutes? [HERE’S WHY]

If a propane heater keeps on shutting itself off, then there is something malfunctioning inside it. There are a number of features which could be malfunctioning to cause this, such as the safety features, the gas supply or the thermostat, and it may need some troubleshooting to solve.

If you have a propane heater, then you might have experienced this: you light the heater to warm your house for the evening. It only runs a for a few minutes before shutting off again – and no matter how many times you relight it, it just keeps shutting off. Why?

Whether you need to get in professional help, or might be capable of fixing the propane heater yourself depends on what precisely is wrong. Below, we’ll discuss some of the possibilities as to why your heater is not working.

Hooking up propane tank to heat for sleep

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What Might Make My Propane Heater Shut Off After 5 Minutes

There are a number of components which might cause this symptom in your propane heater. If you want to troubleshoot your heater, here are the common problems to be on the look out for.

Insufficient Gas Pressure

This is one of the simplest reasons as to why a propane heater may turn itself off – if it doesn’t have the fuel to run, then it will not run. Modern furnaces are specifically designed to only run when a particular pressure of gas is met.

There are a few reasons which can cause an insufficient gas supply, which include:

  • Empty propane tank
  • Blocked gas lines
  • Leaking gas lines

An empty propane tank is something which can be replaced yourself, but we recommend that you find a professional to help you with any damaged gas lines since they can be so dangerous.

Malfunctioning Electrical Connections

If the heater recognises that its connections are loose, then it will shut itself off for safety reasons. Everything from the regulator to the spark plug can have a loose connection.

This is something you should not try to fix yourself, since this is extremely dangerous. So if you suspect that this is your problem whilst troubleshooting, turn the heater off, and call a professional.

The Pressure Switch May Be Off

Certain propane heaters may have specific safety features which cut off the gas supply if the pressure is not all that consistent. If it fluctuates all the time, then the pressure switch may shut off the gas supply in case there are venting problems.

Venting issues may come from a few sources:

  • Blocked exhaust
  • Cracked exchanger

Neither of these issues are recommended to be fixed by yourself. These are both too dangerous to DIY, so call a professional.

Carbon May Have Built Up Around Thermocouple

Propane is a carbon based component, which means that burning it produces carbon dioxide. This means that there may be some carbon build up around the inside of the heater which may cause it to malfunction.

If carbon builds up over the thermocouple of the propane light, then it won’t be able to transfer heat through to the thermocouple and it won’t operate. The thermocouple then won’t be able to signal the valve, and your heater won’t be able to function.

It is technically possible to clean it yourself in approximately twenty minutes, without professional help, provided you take a few precautions.

  • Turn off the gas
  • Take a picture before removing anything so you can put it back correctly
  • Never touch the sensor
  • Use an iron wool or abrasive side of a sponge to scour off any soot
  • Never use any chemical cleaners

Corroded Flame Sensor

The flame sensor may also be one of the reasons why your propane heater might be turning itself off. The flame sensor stays on as long as the furnace is, and will cut the gas supply when it detects no flame.

If the sensor is malfunctioning, then even if a flame is there, it might cut itself off. There are a couple of reasons why this might be:

  • A strong wind may cause trouble for the propane heater
  • A gas leak may cause the flame to struggle

Too Much Distance Between Pilot Light And Thermocouple

The thermocouple, as we have established before, is a device which needs to be very hot before it will function correctly, and if the distance between the flame and the thermocouple is too much, then the thermocouple is not going to function and the pilot won’t light.

You can theoretically fix this problem yourself, if you are careful by:

  • Use a plier to grab either the thermocouple or pilot light
  • Make sure not to use too much pressure or you might break them
  • Pull them closer

So those are some of the major reasons as to why your heater might be shutting itself on and off again. Next, we’ll talk about some troubleshooting for your heater:

Troubleshooting Tips

There are a few things you can do to try and diagnose the problem yourself before calling a professional, and here are our recommendations:

Replace The Propane Tank

This is the simplest first step. Before opening up your heater at all, replace the propane tank just to make sure that it’s not malfunctioning due to a lack of fuel.

Pull The Pilot Light And Thermocouple Closer

This may be the first thing you can do to try and diagnose the problem. Use the pliers to pull the pilot light and thermocouple closer, and then see if that fixes the problem.

Check The Gas Flow

Just to clarify:

  • The gas pilot is the valve which controls the flow of gas
  • The pilot tube carries the gas to the pilot

So if the pilot tube is blocked, the pilot light will not work, and you might have to clean the tube in order to get the light to function.

There are a couple of ways to clean the tube, but the easiest way is to find some kind of long thin cleaning device, such as:

  • Piece of wire
  • Stick
  • Skewer

If you can see it through the tube, then there’s likely a problem. If the pilot light is a weak orange or yellow, then it’s a sign that you must clean the tube immediately.

Check For Loose Connections

You need to then check for loose connections. This is as simple as it seems; look over all the electrical components of the heater and check to see if any of the wires are loose.

Use The Water And Soap Bubble Test For Leaks

Next, you want to check for any leaks on the pipes. A very simple way to do this is to do the water and soap bubble test. There are a few steps involved in this test:

  • Coat all the gas transmission equipment (hoses, pipes, valves and so forth) in soapy water
  • Pressurize the system
  • If you see bubbles forming on any part of the outside, then you have a leak.

Clean The Thermocouple

As mentioned, cleaning the thermocouple is fairly simple, involving just an abrasive sponge or iron wool. Remember, do not use any chemical cleaners or it may break it.

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In conclusion, the reason why your propane heaters may have been turning itself on and off is due to one of three reasons: firstly, there may not be adequate fuel for it to function. Secondly, something may be too dirty to perform its function. Thirdly, something may be broken.

Depending on what the problem is, you may be able to fix it yourself if you are willing to take the heater apart and clean things yourself.