Duo Therm Thermostat Troubleshooting [Issues and Fixes]

We can only imagine how frustrating it would be if your duo-therm thermostat went out in the middle of a hot summer day or a chilly winter night. If you’re traveling, the situation gets considerably worse. 

You search the internet for potential fixes to discover a means to cure it as soon as feasible. There are several different approaches you might take to this issue now. But a speedy repair is required. 

It will take some time to find the problem, and it can be in the most unlikely places. A system reset option may address your issue, but occasionally, the simplest things are the cause. Look at your circuits, especially the ones under your RV’s fuse box, to analyze this problem. 

We’ll address the genuine query: What do you need to fix? And how to do it.

Tools Required For The Fix

A thermostat might be challenging to repair. But in this situation, these appropriate handy equipment can be a lifesaver and can help you out in repair: 

  • Soldering iron
  • Small flat jeweler’s screwdriver
  • Solder

Duo-Therm Thermostat Testing

To check for thermostat issues, you must conduct an appropriate test. It would help if you made sure that the duo therm thermostat is functioning because an old or used thermostat may occasionally be defective. 

Start by turning the switch ON. Then, you should check the DC volts, which should be between 10 and 30, and look at the extremity to ensure they are correct. 

After that, perform a system reset. If nothing happens or there is a problem with the screen, you understand there is a severe problem with the wiring or your thermostat.

Recheck the cables and management to ensure they are fixed if the correct setting doesn’t appear on the screen. If not, you might have to replace the entire device.

Understanding Of Duo Thermostat Troubleshooting

A thermostat for an RV typically lasts 10 to 15 years. That indicates that if you bought a secondhand RV, you might quickly run into some issues with this gadget. 

Numerous factors, such as poor wiring, sand, filth, outdated wiring, and simple wear and tear, can cause thermostats to malfunction. Here we are with some real-time problems and with ways to make fix:-

Thermostat Not Turning On Or Staying On

When the thermostat won’t turn on or won’t remain on, the leading cause is typically a switch issue. It would become powerless as a result. 

The switch may not be receiving any power, and the power might be dropping because of these two reasons:-

1. Cracked Solder Joints

The on/off switch frequently has a broken solder joint. It causes the Duo Thermostat to display the reason for turning off unexpectedly. Let’s see how you can solve this.

Diagnosis: Open the duo therm thermostat enclosure, then remove it. Now look for any cracks in the solder joints. Find any cracks? Let’s figure out how to fix them.

Techniques to fix: Resolder the switch to the board using the soldering iron. Make sure the button fits snugly on the circuit board as you proceed. It guarantees that the solder won’t crack once more.

A quick tip: Use a bit of 25-watt soldering iron for this job. It should also have an end with a finer point. Make sure the soldering iron is electric and not a plumbing soldering iron.

2. Cracked Trace

This symptom can occasionally signify a damaged trace on the circuit board. But this is something that could get resolved quickly. Let’s see how you can solve this.

Diagnosis: Keep the enclosure open and carefully inspect your circuit board. It will be simpler if you run your finger through the board. If you discover one or two cracks, let’s figure out how to fix that.

Techniques to fix: Using a tiny razor knife, gently scrape the green backing from the board. Next, solder a brief section of solid wire across the rift. The wire can resemble a telephone wire.

Push Buttons Not Working 

Button problems are more frequent than you may imagine. You may be pressing buttons that aren’t functioning correctly. This symptom is frequently linked to dust buildup beneath the button.

Accumulated Dust

Your thermostat board may contain dust in various locations because of how frequently you travel with your RV. Now, the pushbuttons won’t function if dust collects below them. Let’s see how you can solve this.

Diagnosis: Start by examining the rubbers beneath the push buttons for dust after opening the thermostat. Start cleaning after checking the other places.

Techniques to fix: After you have cleaned the switches, you should take the PC board out of its enclosure. 

Now, carefully pry off the tabs attaching the top of the switch to the base using a thin, flat jeweler’s screwdriver. 

Spray some contact cleaner; perhaps Q-tips can be used to clean the contacts. Snap the switch’s top back on once everything has been taken care of. Your pushbuttons should now work correctly.

AC Cooling at Wrong Temperature

When your air conditioner doesn’t operate at the appropriate temperature, that’s the sign. Everything you’ll need to handle this on your own is included.

Temperature sensing error

A temperature sensor error is the cause of your air conditioner not cooling at the appropriate temperature. Due to its complexity, this is challenging to solve, but you can attempt it.

Diagnosis: Before the Duo Therm Thermostat turns on, use a thermometer to monitor the temperature of each room in the house. When it stops, take another temperature reading. 

Check the temperatures right away. It should show the accurate reading that is within 3 degrees Fahrenheit. Try the next suggested option if the temperature is still off.

Techniques to fix: What you can do to address this issue is as follows: 

  • Switch off the thermostat. On and off the air conditioner. Restart the thermostat at this point. 
  • Reset the device to factory settings.

To Further Assist You, Below Are A Few Likely Fixes Unique To Ac Units:

  • AC Unit types with solutions:-
  • Rear unit: Get a new upper board
  • Front Unit Without Remote Sensor: Install Remote Sensor
  • Front Unit With Remote Sensor: Check With Ohmmeter and Replace Thermistor Sensor and Upper Board


If everything were in order, life would be so much better. Make sure to purchase the best thermostat to improve your RV lifestyle somewhat. But even after that, you face such issues; we are here with great solutions for you. 

That is why we have shared techniques for fixing Duo Therm Thermostat Troubleshooting here.

Maintaining comfort requires routine upkeep and cleaning to prevent thermostat malfunctions.