How to use a tankless hot water heater in freezing temperatures

[Mox-co]

I had an Atwood tankless heater that came with my Sunnybrook trailer. The manual said the flame would come on at a low level when needed to keep the heat exchanger coil from freezing. Worked until an unexpected cold snap while the trailer was in storage drained the propane. I replaced it with a conventional tank style heater.

I'm going to have to check this.

 

[Mox-co]

I lived in a mobile home in northwest Ohio for two years. The hot water lines always froze first. Freezing is a real concern. Hopefully your heater has the freeze protection. An uncontrolled heat lamp may cause other problems, such as fires. I remember one fire in the park from thawing frozen water lines with a heat lamp. This story did not have a happy ending.

I'll keep this in mind, thanks

 

[Mox-co]

Just wanted to thank the community for all the valuable information. I have some research to do before moving forward, but maybe the answer is in the product literature. I'm hoping the tankless on demand water heater has freeze protection. If not, I will have to work something out.

 

[Martian]

You say that you are not concerned about the water lines freezing because they are PEX. However all the fittings are not PEX and are usually fairly brittle plastic. PEX lines can and will freeze but do not sustain major damage. Your lines will be frozen and most fittings will be split. That can lead to some beautiful icework hanging from the bottom of the unit. Be sure to take photos.

 

[klook]

The heater exhausts thru a small pipe that comes to the door and has a rubber grommet. Fiberglass with no paper vapor barrier would work. But if its in a 2025 Jayco, I would bet money it has the freeze protection built in. As long as there is propane.

 

[klook]

If electricity is more reliable for you look into the Cheap Heat units.

 

[Mox-co]

The heater exhausts thru a small pipe that comes to the door and has a rubber grommet. Fiberglass with no paper vapor barrier would work. But if its in a 2025 Jayco, I would bet money it has the freeze protection built in. As long as there is propane.

First thing when I get home in March, I'm going to check for this feature.

 

[RayIN]

Well if it does not have freeze protection, cover the door to insulate it a little and put a rough treatment 120v bulb in there. They give off more heat then light. Used to be what the old timers used in outside well houses up in the North. A 100 watt bulb is hot. They are an enclosed box so putting heat behind them does not work well.

I used to use a reptile heater element instead of a light bulb, same heat, no light.

 

[klook]

I used to use a reptile heater element instead of a light bulb, same heat, no light.

Sounds like a great idea.

 

[Srex52]

I am planning a work trip to eastern PA in March. My concern is the tankless hotwater heater may be exposed to below freezing temperatures. I was thinking of a heat lamp in the water heater area. I also looking for suggestions. What do you think?

Check your units manual. I have a tankless on my Cougar 5th wheel and it will cycle on periodically when it is below 38 degrees. Other than that I would use your pump and fill it with antifreeze.