Do RV Thermostats Go Bad? How To Check It?


If your RV starts getting warm when you know you’ve turned on the AC, you might be tempted to blame your AC system. But don’t be so quick to set up an appointment to get the entire system replaced. The problem may reside with your thermostat.

Do RV thermostats go bad? Yes, RV thermostats can go bad. However, most RV thermostats have a lifespan of about 15 years. If your thermostat is around this age, it can go bad. Other factors such as dust, wiring issues, and dead batteries may contribute to an RV thermostat failing to work, but the most common is a thermostat that has reached the end of its lifespan.

But how can you tell if your thermostat needs to be replaced? What can lead to the thermostat going bad in the first place? The answer may be simpler than you think.

How Can an RV Thermostat Go Bad?

The most common cause of your RV thermostat going bad is age. You may not know the exact age of the thermostat if you’re purchasing a used or refurbished RV, but if the RV is at least 10-15 years old, the thermostat may be on its way out.

Here are some other common reasons that RV thermostats may go bad:

Reason #1: Old wiring. Even if the thermostat itself is newer, the wiring that connects it to the system may be failing.

Again, if your RV is older than the thermostat (or at least 10 years old), this is worth checking out before replacing either your thermostat or your AC system.

Reason #2: Poor wiring. This ties in with older wiring, but in some cases, it is less obvious. If the thermostat was replaced, the wiring may not be done correctly.

Sometimes, the thermostat can work fine at first, and then suddenly stop working months later.

Especially if wires are not securely connected, they run the risk of getting disconnected while your RV is in motion. Make sure that you check your wires no matter how old they are to eliminate any potential problems there.

Reason #3: Dust. Your RV sees many more diverse environments than your home does.

This, paired with the fact that it may sit for months at a time, can lead to dust building up in the RV’s mechanical systems.

This dust can get inside the unit, inside your AC or heating units themselves, and just about anywhere else.

Most older thermostats have a removable faceplate. If there is dust built up under this faceplate, blowing it out with compressed air can sometimes fix the problem.

Reason #4: Dead batteries. If your thermostat has a battery to keep it running, the risk of it not working over longer periods increases.

The thermostat itself may work fine, but a dead battery can make it stop functioning, leading to most of the same problems that might persist if it went bad.

Check your RV’s battery and replace it if required. Sometimes, this is all the thermostat needs to continue functioning at its best.

How Can You Tell If Your RV Thermostat Needs to Be Replaced?

Chances are you’ve experienced at least one of the following signs if you are reading this article. Let’s take a look at some of the ways that you may be able to tell if your thermostat needs to be replaced.

No Display

If your thermostat won’t switch on after it’s been off a while, it may be a sign that it needs to be replaced. A blank screen with no display whatsoever is concerning.

If you have a thermostat with a digital display, try changing the battery. This should be located inside the faceplate.

If changing the battery doesn’t help (or if your RV thermostat doesn’t have a battery inside), it may be time to look into replacing the thermostat.

Temperature Display and RV Temperature Don’t Match

Whether you have a digital thermostat or an older style, you’ll be able to tell if there is a difference between the temperature that you have it set to and the temperature inside your RV.

If you have your thermostat set to 70 degrees and your RV is warmer inside than outside, there might be a problem with your thermostat.

In this case, the air conditioning won’t kick on because the thermostat isn’t correctly gauging the temperature. According to the thermostat, there’s no need to turn on the air conditioning.

This may mean that it’s time to take a deeper look at your thermostat and its wiring.

Troubleshooting if a Thermostat is BAD: Explained! >> Check out the video below:

Air Conditioning/Heat Won’t Respond

If your thermostat appears to be working fine but doesn’t turn the AC or heat on when you tell it to, the problem may well be in the unit itself.

Try setting the temperature to the highest or lowest setting to see if it can get the system to work properly.

You should hear a ‘click’ inside the thermostat when it engages the heat or AC. If there is a ‘click’, the thermostat is functioning fine – it’s another system that is causing the problem.

However, if the thermostat stays silent, it’s a good indication that it isn’t working properly.

Air Conditioning/Heat Won’t Turn Off

Sometimes you can have the opposite problem. When your AC or heat continues to run after the thermostat should have switched it off, look closely at your unit.

The first thing you should do is attempt to turn the thermostat completely off.

If the thermostat remains off but the heat or AC continues to run, there may be a problem with the way your thermostat is signaling the rest of your AC system.

Check your wires. If you don’t see any frayed, damaged, or disconnected wires, it’s time to see an electrician or replace your thermostat.

The Wrong System is Engaging

If your thermostat keeps kicking the heater on in the middle of summer (or blasting the AC when it’s snowing outside), it might be calibrated or wired incorrectly.

Make sure that you have the thermostat on the right setting first, of course.

If you are doing everything right but the thermostat still wants to get the systems crossed, it may be a wiring issue. It could also be an issue with the thermostat itself, so it’s important to get it checked.

What Happens If My Thermostat Batteries Die?

When your thermostat battery runs out of charge, you will see a blank display area, and the thermostat will stop functioning.

Your heating and cooling systems would then no longer function because they react to your thermostat’s temperature controls.

Generally, thermostats will warn users by a low battery indicator light or bleeping. You will find it impossible to adjust your thermostat, and your AC system will no longer be operable.

The batteries in your thermostat are not there merely for the LED display screen, but it also functions to send a voltage signal to your circuit board for temperature control.

If your batteries can produce voltage, your AC will malfunction because the thermostat can no longer regulate it.

Most modern thermostats will start giving warning signals a month or so in advance, so you will have [plenty of warning that your batteries are running low.

Considerations for Replacing Your RV Thermostat

Whether you’re taking on the project yourself or getting your thermostat replaced by a professional, there are a few things you need to consider before you move ahead with the project.

First, never buy a refurbished thermostat. Yes, it may be cheaper, but chances are you’ll spend more in the long run. As we’ve mentioned, a new thermostat should last between 10 and 15 years.

If you buy one that has been refurbished, there’s no telling how long you have left. Don’t buy another thermostat in a year.

Consider buying a digital thermostat. Even if you have an older RV, it may be worth it to upgrade to a digital thermostat. Some can be programmed to raise or lower the temperature based on the time of day.

More than that, a digital thermometer can help you control your temperature more exactly than an older one.

It’ll also last longer in most cases. You won’t have to do this all over again soon. You may not have to update your wiring, either!

DIY at your own risk. If you aren’t confident in your ability to replace your thermostat, don’t try. You may end up causing more damage to your RV’s electrical system.

Professional installation may be more costly upfront, but it can make all the difference in the long run. Plus, most professional work will have some sort of warranty if it breaks again.

How Much Does It Cost To Replace The Thermostat?

The cost of a thermostat in your RV depends on various factors, such as whether you plan to replace the thermostat yourself and the particular thermostat you have chosen.

How much does it coest to replace the RV thermostat? A rough guide would be between $150-$250 for a good quality thermostat, and you would pay about $200 for an average auto electrician labor fee for the job. So you are looking at anywhere between $350-$550 for replacement and installation.

Installing your new thermostat could be as simple as a few screws, or it might necessitate a complete rewiring of your system.

Upgrading your RV thermostat might entail more electrical know-how than you think and it is recommended that you bring in a professional to ensure that it is installed correctly. You don’t want to damage other parts of the system.

As an alternative, you might consider a Smart RV Thermostat, such as the Zedly system.

The Zedly system Integrates with your mobile phone via an app, and the new smart WiFi system offers some great features.

The system retails at between $199 and $249 with a monthly subscription of around $5. The Smart Wifi system provides:

  • Programmable 12-volt thermostat with a timed action
  • The thermostat has its own Cellular connection, so you are not reliant on campground WiFi
  • Security features such as people opening your RV door signals on your mobile
  • Pet safety
  • Alerts are sent to your mobile if your RV is too hot or too cold
  • Pet safety alert tells you when your pet safe temperatures rise or drop and alert you, or your designated numbers in emergencies (such as the campsite main office, or a friend nearby.) Should you be out of range or your mobile dies, your pets would be safe.

An important factor in replacing your RV thermostat is that the replacement is compatible with your HVAC system.

Don’t be fooled by brand name compatibility because some brands such as Dometic is not compatible with all their own systems.

Ensure that your new thermostat will be compatible with your particular RV stem by either consulting a retailer or finding out from your system manufacturer before purchasing a replacement.

Why Is My Heat On When The Thermostat Is Off?

The most common symptom that your thermostat is faulty is when your AC/heater runs continuously and won’t shut down.

There may be a loose connection, a frayed wire, or your thermostat may have been miscalibrated.

To make sure that your thermostat is the cause for your heat being on when it shouldn’t, you should do the following:

  • Make sure your thermostat is on the right setting. Often the thermostat can be set to the ON setting when it should be on AUTO. The ON switch makes your unit runs continuously, whereas the AUTO setting only runs the system when the unit is cooling or heating. 
  • Turn down your thermostat 5 degrees lower than average (summer) or 5 degrees higher than average (winter). You should hear your system click in and either release more heat or draw air for cooling.
  • Check the batteries of your thermostat. Replace the batteries and see whether the system returns to normal activities
  • Check and test wire connections. Remove the thermostat panel and check if there are any loose or frayed connections
  • If the wires are all secured, you should consider bringing in an HVAC technician, as tampering with wires may be dangerous. 

Alternatively, your heating may be running continuously due to faulty wiring somewhere else in the HVAC system, a broken switch, or a defective heating sensor.


Do you think your RV thermostat may be going bad? It’s not out of the question, either due to age or some other issue.

Remember to always check if your thermostat may be causing the problem before you make an appointment to replace your AC system.


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Mike Gilmour

Hi, I'm Mike, co-founder, and editor of RV and Playa. My passion is traveling (with my RV) and enjoying the day at the beach (Playa)! Well, I originally created this blog as a way to share what I've learned by experimenting with the RV lifestyle, and I want to help others develop in life through new skills and opportunities.

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