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

by Fred
(Henderson , NC)

This is Why Your RV's Heater Keeps Cycling on and Off

This is Why Your RV's Heater Keeps Cycling on and Off

I just bought a travel trailer. When the furnace is turned on, it will run for about 5 minutes, then cut off for about 5 minutes, then back on and off. The furnace is set to 90 to try to make it run nonstop but continues to do the same is this normal?

ANSWER: Hi Fred, 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. Setting the furnace temperature to 90 degrees will not solve the problem

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 expensive problems.

1. Check inside your trailer to ensure 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 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, 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. RV thermostats can be stand-alone thermostat just for the furnace, or it could be a dual thermostat that also controls your RV's air conditioner. Try replacing the Furnace's Thermostat. RV Furnace thermostats are 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, 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.

The video below will outline the different types of RV Thermostats as well as some Troubleshooting tips

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The Video below shows you how to replace your RV's Thermostat




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 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.

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

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furnace on and off
by: timmccoy

I have a 91 gulf stream friend ship.i wish I had a better idea where to spray compressed air i will find it.thank you for your help with my question.

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furnace operation
by: Anonymous

just a little FYI. Suburban and RV furnaces have a fan for exhaust, usually the same supplying air flow inside. The exhaust airflow sensing switch allows the next step, propane solenoid opens and spark is initiated, unit will attempt to light several times, there is a flame sensor which will tell the unit if it fired up or not. Usually after several failed attempts the unit will try no more but keep blowing air.

Normal operation the flame will cycle on and off but flame will burn over one minute before cutting off for a minute. when temp is reached indoors flame is extinguished and the fan will run until cooled. when indoor temp drops repeat normal operation.

hope this helps.

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Heat
by: Anonymous

I have a 2019 Gulf Stream innsbruck I turn the heat on it runs for a couple of mins then shuts off need heat tonight can some one help please

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Heater
by: Anonymous

I turn the furnace on and it runs for about 2 minutes and turns off and I have to turn it off and back on , it never stays on long enough to get warm , ideas?

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RV furnace clicking but won't fire up.
by: The Vixter

Brenda, I had that issue with my new 2016 Thor Ace 30.1 which I purchased new in 2017. It had been sitting in a Camper World lot for quite some time.
When we first needed to use the furnace, it too did the on/off clicking. I opened the furnace compartment and took the circuit board out and found that water had accumulated in the tray and was shorting out some of the circuits. After drying it out and cleaning the corrosion it worked fine and did not have to get a new circuit board.

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Thermostat Anticipator
by: Larry M

There is an adjustment on all thermostats called the "anticipator." The purpose of the adjustment is to modify the cycle length.

(OK to skip this paragraph)
Without getting too complicated, it slightly preheats the thermostat when the furnace is off, so the trailer gets a little colder than the thermostat setting. When the furnace starts, the anticipator stops heating, so the furnace has to run until the trailer meets the actual thermostat setting. The difference between these two settings (called "hysteresis") is what results in longer, less frequent cycling.

The adjustment itself is either visible when you remove the thermostat cover, or visible on the back side of the thermostat base when you remove it from the wall.

Usually you set it to the furnace manufacturer's recommendation, 0.8 for the Suburban SF line if I recall correctly. But if you are unhappy with the cycling rate, you won't break anything by changing it. Make small changes.



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furnace stops in night when cold out
by: Jon L

My camper trailer is an 1989 Lynx 30ft, and the furnace appeared to work fine until the temperature outside drops well below 0. Then the furnace fails to do anything at all. Appears to be no power to thermostat when this happens despite the wires being connected correctly and the thermostat itself still works. Is the internal components of my furnace being affected by the cold?? When morning comes and the temperature rises a bit the furnace suddenly starts working again all on its own? solutions?


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Furnace cycles on and off before temp is met
by: Phil Bowman

What I have found out in our RV is there is a heating vent close to the tstat which is heating the tstat up quickly and shutting the furnace off.
I simply sit something over that vent and the tstat allows the RV to heat properly.

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Control Board Modification?
by: Anonymous

Hello,
I have a 2006 Komfort 282TS with a Suburban furnace. One issue I had last winter was my control board inside the furnace kept frying, apparently because they're made extremely flimsy and end up basically melting or overheating to the point where they stop working.

I had an RV tech come out and he replaced it, but it happened three or four times and he was no help in finding an alternate solution. Is there anyway to mount that stupid little board OUTSIDE the furnace cover? I am a full time student trying to live cheaply off my GI Bill and can't afford to spend 600$ a winter on mobile visits and new circuit boards that just happen to die after the 30 day warranty. Any help would be appreciated. Thanks :)

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Suburban furnace
by: Dana

Hi, I have suburban furnace that keeps cycling but when you touch the red and white wires from thermostat it works fine.when you put the wires back to thermostat it keeps cycling won't shut off until I take furnace fuse out .

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Check propane supply
by: Anonymous

In my trailer that cycling means the furnace is not getting propane. Start with the simple stuff like does the tank have anything in it? Is the tank valve open? If you have two tanks, is the tank switch turned to the same tank as the one that is open? In my tailer thee is a light on the refridgerator that blinks if set to gas only and the gas is empty. Very easy way to check without going outside.Also I have one of those autoswitches that automatically switches tanks when one runs out. I keep the valve off on the not in use tank so that switch thing doesn't work because that way I always know when one tank is empty and needs refilling while I have a spare. I don't get caught with no propane.

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heat
by: Anonymous

Be sure your propane is turned on and that the tank has not run empty.

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Misleading the poor person!
by: Johnny B

Hi there. I feel that some of these comments, although helpful might be misleading. I am also a new RV's and have a 2011 Starcraft AR-One. I can withstand colder temps than most people in this region however the last time I went camping it was chilly enough to use the furnace. My furnace did the same thing that you are stating yours is doing. Mine was doing it because after the temp was reached and the furnace turned off the temp fell low enough within 10 minutes or so to kick the furnace on again. My trailer is only 14FT so it doesn't take much. Although somewhat annoying it was nice to wake up to a warm area.

Just my two cents.

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Furnace problem
by: Brenda

I have a 1983 Aljo Aly Alliance 5th wheel, which I live in. My furnace is a Duo Therm L-342465, model 65930-064 forced air direct vent. When I turn the thermostat on, the fan comes on, then after a few seconds it starts clicking. What's up? Sometimes it works, but mostly it just clicks and cold air comes out.

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