Why Does My RV Furnace Keep Cycling On And Off Every 5 Minutes?

by Fred
(Henderson , NC)

Just bought travel trailer. When heat turned on it will run about 5 min then cut off for about 5 min then back on and off. Heat is set on 90 to try to make run nonstop but continues to do the same is this ordinary?

ANSWER: Greetings Fred thanks for submitting your question on our Ask An RV Question Page.

What you are experiencing with your RV Furnace is not normal. RV Furnaces are designed to shut off once the proper inside temperature is reached. Once the temperature falls below the thermostat setting, the furnace is designed to cycle back on. Since your furnace is never reaching the proper inside temperature and just cycles on and off that means that it is not functioning properly.

Since you do not tell me what make or model RV Furnace you have, I can only outline common problems found in RV furnaces that could be causing your furnace to malfunction.

We will start with the problems that have the easiest solutions and work our way to the more complicated and possibly more expensive problems.

1. Check inside your trailer to make sure that none of the furnace vents are blocked by furniture, boxes, etc. Blocking the furnace vents of the RV can cause problems with the furnace.

2. The exhaust on your Furnace could be obstructed causing the furnace to overheat and triggering the Temperature Limiter Switch which keeps shutting down the Furnace. Outside of your trailer you will find a furnace exhaust vent. You need to open up the vent compartment. This may require unscrewing the furnace vent cover or there could just be a simple latch to open.

Since you do not tell me what make or model RV Furnace you have, I can only outline common problems found in RV furnaces that could be causing your furnace to malfunction.

We will start with the problems that have the easiest solutions and work our way to the more complicated and possibly more expensive problems.

1. Check inside your trailer to make sure that none of the furnace vents are blocked by furniture, boxes, etc. Blocking the furnace vents of the RV can cause problems with the furnace.

2. The exhaust on your Furnace could be obstructed causing the furnace to overheat and triggering the Temperature Limiter Switch which keeps shutting down the Furnace. Outside of your trailer you will find a furnace exhaust vent. You need to open up the vent compartment. This may require unscrewing the furnace vent cover or there could just be a simple latch to open.

Sometimes birds, spiders, mice, etc. go into these vents and create little homes obstructing the vents. which causes the Temperature Limiter Switch to cycle the furnace on and off due to the furnace overheating. With the RV's furnace shut off use a can of compressed air to blow out the vent. Be careful because you will have soot and dirt flying out of this vent directly at you. Once the vent is completely clean, put the access door back on and turn on the furnace and see if this corrected the problem. If not, move on to the next step.

3. Your RV Furnace's Thermostat could be bad. I am going to have to assume that your trailer's furnace has its own separate thermostat. Try replacing the Furnace's Thermostat. RV Furnace Thermostat's are relatively inexpensive and easy to install so it is worth a shot to try replacing one and see if that fixes the problem; before you take the RV in to have it repaired by an RV Technician.

If you have a dual thermostat that controls the furnace and your trailer’s A/C then you may not want to try this step as these Dual Thermostats are a little pricier and a bit more complicated to install. Again try the furnace and see if the new thermostat resolved the problem.

Warning: I am now going to outline some more complicated and expensive fixes for your furnace. If the steps above did not resolve the problem, I strongly suggest you take your trailer in and have a Qualified RV Technician properly diagnose and repair the problem with your furnace.

4. You could have a bad Temperature Limiter Switch in the furnace; you could have a bad Furnace Circuit Board.

5. You can also have some issues with propane flow to the furnace.

I hope that this information was helpful to you.

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Happy RVing

RVing Al