Atwood – Dometic RV Furnace Red Light Flashing (Meaning)

The codes are not universal. This is one aspect of RV life you need to get used to. When different models come out they are given different codes. This can confuse people even though all the 8500 series have the same codes but the 7900, 8000 & 8500 2-stage models have their own independent codes.

If the model series is an 8525 number, then the single red light flashing means you have a limit switch/airflow problem. But it could also mean you are locked out and need to reset the thermostat. To do that shut the heater off and disconnect the power supply for roughly 10 or 15 seconds.

To learn more about this topic, just continue to read our article. It has the information you want to know about to solve this error code problem. Just make sure you find the right codes for your model series.

What Does It Mean When Your Furnace Has a Blinking Red Light?


Sometimes it is hard to say as codes can be different from model to model. But with the 8500 series, you should have the same code and the explanation is a lockout when a single red light flashes.

However, if you get a single red light flashing and your heater starts for 5 minutes or 10 minutes and then shuts down, there is another problem. This problem could be that there is low LP pressure to the heater or other appliances.

One more problem that could be causing this red alert is the control board. Unfortunately, the control boards are made in China and they are not the best you can buy. These boards fail quite often and this is a common not rare event.

The best thing to do when the control board goes bad is to replace it with a better after-market option that is built to better standards and quality levels. The prices for these after-market boards will vary, so make sure to shop around first.

Also, some of the control boards made around 2004 had the fan relay attached to the board. Your replacement should have the same set up if that is the one you have.

Dometic RV Furnace Red Light Flashing


Usually, this flashing light is telling you that there is an ignition lockout going on. The ignition lockout is triggered when a sensor detects an unsafe situation. It then sends that message to the controller which in turn shuts off the power and the fuel supply.

The source for this situation can vary and it may be due to a bad control board, a faulty sensor, or even a real problem that needs to be taken care of. The flashing light is separate from the E1 code you may see from time to time from the Dometic furnace.

When you see the E1 code that means that the thermostat has lost communication between it and the modular board. When that happens the system can shut down.

This error code usually happens with the zone 2 AC unit so if you do not have one, you may not have to worry about this loss of communication. Resetting the thermostat is one option you can try to solve the problem.

If that doesn’t work you may have to call in a repairman to diagnose the issue and fix it for you. Or you can try to look up the solution in the manual but sometimes those manual troubleshooting sections do not cover every issue that can go wrong.

Atwood RV Furnace 3 Flashes


This is similar to the Dometic and it is an ignition lockout. However, the problem is not always easy to solve. There is what is called a soft lockout which gives you three chances to reset or fix the problem.

The source for the lockout would be either the defective flame sensor or a defective ignitor. Once the three tries to re-start have failed, the system goes into what is called a hard lockout.

That is when you may need a skilled technician to help you. There may be other sources that cause this issue but they may be beyond your expertise and skill levels, not to mention on-hand equipment.

How To Solve These Issues


There are some solutions you can try first. There is no guarantee any of them will be the source of the problem or that there is not more than one issue causing the lockout.

1. Reset the furnace- you need to push the + button and hold it while pressing the on/off button at the same time. Your manual should have the exact instructions to reset your furnace.

2. Clean or replace the sensors- if you try the first option and the furnace doesn’t work, go to the second one as the sensors may have gone bad on you. There are all sorts of sources for the sensors to get dirty and cause them not to work

3. Replace the air filter- the same thing applies here. All the dirt, soot, and other debris that gets inside your furnace can clog up the air filter and cause the furnace to shut down. The lack of airflow is a symptom of the lockout.

Why your Atwood Furnace goes to lockout is due to many sources including the following-- low/high water pressure, lack or no fuel supply, system blockage, or electronic part power failure.

Some Final Words

The error code system is not a perfect system. This is why you need to keep a copy of the manual handy. It will list the different codes so you know what is wrong.

Unfortunately, the manual may or may not tell you how to solve it or it may simply say call a repairman. In many cases, there is no shame in calling a repairman as not everyone is a handyman who can fix modern devices especially when the error codes are not universal.

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