How To Tell If RV Thermostat Is Bad? – 3 Common Signs

how to tell if rv thermostat is bad

The thermostat is an important device in your RV because it helps regulate the RV temperature and activates certain equipment when the temperature goes beyond desire. The last thing you need is to get this device to malfunction in the middle of your RV trip. So, how to tell if RV thermostat is bad?

There are certain signs which can tell you that the thermostat has gone bad. Such signs include an unresponsive screen, unusual RV temperature, and inability to switch the heater or air conditioner (AC) on/off.

Let us dive into these signs more clearly below.

Is RV Thermostat Bad? Watch These 3 Signs

Sign #1- Black Screen


One of the obvious signs that your RV thermostat has gone bad is an unresponsive or black screen. This condition might be due to a loose connection to the electrical circuit. The thermostat wiring might have loosened and disconnected from the unit during travel.

In this case, you need to replace the broken RV thermostat with a new one. But before you replace the thermostat, check whether the cause isn’t just dead batteries. If your RV thermostat remains unresponsive after changing the batteries, then you need to replace it with a new one.

However, an unresponsive screen might only be applied for digital thermostat models. Mechanical thermostat models don’t have a display screen, so Sign #2 is a better indicator of a faulty thermostat.

Sign #2- Unusual RV Temperature


When you feel too hot or too cold inside your RV, check your thermostat settings. If the settings say normal temperature, but you feel otherwise, then you got a broken thermostat. The operation of the RV thermostat becomes inefficient when the device can’t detect the current room temperature.

Try turning the heater up. If you don’t feel any temperature change inside the RV, then the device may require recalibration.

You can also use a separate thermometer to read the room temperature. If the readings are not the same, then your thermostat might be faulty. Your AC won’t kick in if your thermostat thermometer thinks that your RV temperature is already cool.

Sign #3- Can’t Turn The Heater Or AC On/Off


Your thermostat could also be bad if you can’t switch your heater or AC on. Sometimes, the reasons for no power could be dead batteries or wiring issues. Wiring defects prevent the thermostat from operating efficiently as it fails to send and receive electrical signals.

Oftentimes, faulty thermostats blast the heater or AC incessantly despite trying to switch it off. In this case, the cause could be due to frayed wiring or incorrect calibration of your thermostat unit.

You can take the thermostat out from the housing and check the wiring for any damage. If you can’t see any damage, you can get the unit tested by a professional or simply replace it with a new one.

Troubleshooting Tips for Bad Thermostats

Sometimes, a quick fix is all you need to save your RV thermostat. Here are some simple things you can do to fix your RV thermostat when it starts to get faulty.

1. Make Sure To Get The Right Setting


The thermostat should be on the heater set during the cold days and the winter setting during the hot days. If you notice that your AC or heater is running nonstop, switch the control panel from “ON” to “AUTO” to automatically adjust the temperature inside your RV. The auto mode will also let the appliances only blow air when they’re heating or cooling the air inside your camper van.

2. Set The Thermostat +-5 Degrees


During winter, set the temperature to 5 degrees higher than the temperature outside. Conversely, set the thermostat to 5 degrees lower than the outside temperature when it’s summertime. These adjustments should help keep your RV at the most efficient temperature.

You should hear an audible “click” sound when you adjust the thermostat settings. That clicking sound is a relay closing sending a signal to your AC or heater that it’s time to turn on the power. After a couple of minutes, the supply register vents will blow or draw in air from inside the rig.

3. Replace The Batteries


Most RV thermostats are digital models, so they need batteries to work efficiently. If you see that your thermostat is no longer working properly, try replacing the batteries because they might have drained out. To ensure optimum function, replace the batteries each year.

The thermostat should function well after getting new batteries. However, if the thermostat is still dead, then you should check the wiring next.

Your thermostat can be powered by the electrical system of your rig. All RV thermostats work on 12V, so you might need to check the fuse if the unit isn’t working. If it is damaged, replace it.

Air Blast The Dust Away

For mechanical thermostat models, dust accumulation is often the problem of malfunction. The dust can jam the mechanical parts inside the device. Oftentimes, you can meet this problem with refurbished thermostat models.

To clean the unit, remove the cover and use a can of compressed air to blow the dust away.

Check The Wires And Connections


When none of the troubleshooting tips can solve the problem, the culprit is probably the wiring. Seek the services of a professional to test the wiring of your RV thermostat.

If you have ample experience, do it yourself. Check the wiring connections and find any loose wires. Then, reconnect these stray wires and see if it makes any improvement.

Replacing a Bad RV Thermostat


Once you’re certain that your thermostat is bad, it’s time to replace it. Here are the steps that you can do for a simple thermostat replacement.

Step 1: Pick A Good RV Thermostat

Choose a thermostat that’s highly rated and compatible with your particular RV model. Ensure that your new thermostat has the right size to replace the broken one.

As much as possible, keep away from refurbished thermostats because they rarely include a warranty, and they tend to malfunction quickly. Always make sure to buy a new thermostat that comes with a warranty to ensure quality.

Step 2: Remove The Bad Thermostat

Before you start replacing the old RV thermostat, turn off the power supply in your RV for safety precautions. Check the manual of your old thermostat to learn how to remove the device from the wall. Take a snapshot of the wires and wall mount for future reference.

Step 3: Mount And Install

Refer to the product’s manual on how to mount and install the new RV thermostat. Then, use your reference photo to learn where to wire the thermostat on the wall.


After reading this article, I hope you know how to tell if RV thermostat is bad. Three signs include a black screen, RV temperature not matching the thermostat settings, and can’t turn the heater or AC on/off. You can do some troubleshooting skills to fix the problem, but replace it with a new one if none of the quick fixes don’t work.

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