Can On Demand Water Heaters Survive Cold Weather

**Nuffsaid** · 02-07-2024, 07:27 AM

This is just a thought I had that I don't know the answer to, but can an on demand water heater survive winter weather without freezing up and possibly getting destroyed?

**llr2800** · 02-07-2024, 10:51 AM

Apparently it depends, I have been following them as I am getting new camper and there are few if any without it.

Some of the earlier ones people were adding heating pads to help. Some of the later ones will run the heat when the temperature gets too low.

You will need to research your exact band and model, to see what if anything you need to do.

**Nuffsaid** · 02-07-2024, 10:59 AM

I don't currently have one, but since I have survived -44F in my Solitude with the tank type 12 gallon water heater with no issues even after my fresh water froze up, I just wonder what happens with the tankless water heaters. If they are exposed to cold air from outside they could potentially freeze and get damaged. But I don't know a thing about the RV tankless water heaters. I have a fair amount of experience with tankless water heaters in residential applications and I can tell you that they don't survive in areas like mine with hard water.

**Soundsailor** · 02-07-2024, 12:58 PM

I don't think a tankless will do well in prolonged exposure to below-zero weather. I don't camp in the winter, but I've thought about it a bit, and I think the whole coach would have to be set up well for winter weather. My Reflection 150 has thinner walls and less insulation, so it is NOT set up for winter weather. As @llr2800 said, the newer models of the TWHs are better able to survive cold temps. But I would want the TWH's compartment to have extra insulation. And a bilge heater would be a plus, the yachting types have been dealing with cold for a long time.

**retired_engineer** · 02-07-2024, 01:59 PM

Based on a conversation I had with Furrion their more recent tankless water heaters are supposed to be usable below freezing. They wouldn't say how low. I'm going from memory but below 38F outside they will run the burner when they detect the unit has dropped below 52F. There is no mechanism to keep the water heater from freezing while traveling. Based on my experience here at the house the location of the water heater is probably involved as well. Ours is under the sink inside the heated area of the trailer. I had the heat running when we had some freezing temps and the water heater did not freeze up even though it was turned off. We were above freezing during the day so make of it what you will.

Truma has one rated for below freezing that circulates the hot water and cycles the burner when it gets too cold. They also have a 12VDC heater and pump that is suppose to keep the heater from freezing while traveling.

I do not know about the freeze protection of other brands.

I do not consider the Furrion fully freeze protected because there is no travel mode. It also has to be winterized with antifreeze due to its design. Unlike a tank style heater you just can't drain and bypass the thing and be good. We haven't fully decided but we are leaning to going back to a tank style water heater to regain our extended camping season. The alternative is to go with the Truma. Either one of them involves some rewiring and/or replumbing but I expect the Furrion to be gone by next winter.

**Nuffsaid** · 02-08-2024, 07:15 AM

Originally Posted by retired_engineer

Based on a conversation I had with Furrion their more recent tankless water heaters are supposed to be usable below freezing. They wouldn't say how low. I'm going from memory but below 38F outside they will run the burner when they detect the unit has dropped below 52F. There is no mechanism to keep the water heater from freezing while traveling. Based on my experience here at the house the location of the water heater is probably involved as well. Ours is under the sink inside the heated area of the trailer. I had the heat running when we had some freezing temps and the water heater did not freeze up even though it was turned off. We were above freezing during the day so make of it what you will.

Truma has one rated for below freezing that circulates the hot water and cycles the burner when it gets too cold. They also have a 12VDC heater and pump that is suppose to keep the heater from freezing while traveling.

I do not know about the freeze protection of other brands.

I do not consider the Furrion fully freeze protected because there is no travel mode. It also has to be winterized with antifreeze due to its design. Unlike a tank style heater you just can't drain and bypass the thing and be good. We haven't fully decided but we are leaning to going back to a tank style water heater to regain our extended camping season. The alternative is to go with the Truma. Either one of them involves some rewiring and/or replumbing but I expect the Furrion to be gone by next winter.

I guess I made a poor assumption that these tankless heaters are propane, but if it is located under the sink I would assume it is 110V am I correct? I like to boonedock or camp in my daughters front yard, LOL, I don't like having to rely on electric. I have a small on demand electric water heater in my shop mainly so I can have warm water to wash the grease off of my hands. It works ok but I wouldn't keep up with a shower.

**llr2800** · 02-08-2024, 07:24 AM

Originally Posted by retired_engineer

Based on a conversation I had with Furrion their more recent tankless water heaters are supposed to be usable below freezing. They wouldn't say how low. I'm going from memory but below 38F outside they will run the burner when they detect the unit has dropped below 52F. There is no mechanism to keep the water heater from freezing while traveling. Based on my experience here at the house the location of the water heater is probably involved as well. Ours is under the sink inside the heated area of the trailer. I had the heat running when we had some freezing temps and the water heater did not freeze up even though it was turned off. We were above freezing during the day so make of it what you will.

Truma has one rated for below freezing that circulates the hot water and cycles the burner when it gets too cold. They also have a 12VDC heater and pump that is suppose to keep the heater from freezing while traveling.

I do not know about the freeze protection of other brands.

I do not consider the Furrion fully freeze protected because there is no travel mode. It also has to be winterized with antifreeze due to its design. Unlike a tank style heater you just can't drain and bypass the thing and be good. We haven't fully decided but we are leaning to going back to a tank style water heater to regain our extended camping season. The alternative is to go with the Truma. Either one of them involves some rewiring and/or replumbing but I expect the Furrion to be gone by next winter.

Could you please elaborate why it won't work during travel? This is the 1st I heard of this.

I have heard about some people using standard household heat tapes, these would be 120V and not work in travel.

**Soundsailor** · 02-08-2024, 07:56 AM

Originally Posted by Nuffsaid

I guess I made a poor assumption that these tankless heaters are propane, but if it is located under the sink I would assume it is 110V am I correct? I like to boonedock or camp in my daughters front yard, LOL, I don't like having to rely on electric. I have a small on demand electric water heater in my shop mainly so I can have warm water to wash the grease off of my hands. It works ok but I wouldn't keep up with a shower.

The TWH are propane. They do need 12-volt power to run but the fuel is propane. They work great while boondocking, we never run out of hot water.

**retired_engineer** · 02-08-2024, 08:36 AM

Originally Posted by Nuffsaid

I guess I made a poor assumption that these tankless heaters are propane, but if it is located under the sink I would assume it is 110V am I correct? I like to boonedock or camp in my daughters front yard, LOL, I don't like having to rely on electric. I have a small on demand electric water heater in my shop mainly so I can have warm water to wash the grease off of my hands. It works ok but I wouldn't keep up with a shower.

The Furrion uses propane and 12VDC for the control board. I was just mentioning the location in regards to my opinion that the water heater location could have an effect on its freeze resistance too.

Originally Posted by llr2800

Could you please elaborate why it won't work during travel? This is the 1st I heard of this.

I have heard about some people using standard household heat tapes, these would be 120V and not work in travel.

The Furrion water heater relies upon the gas burner to keep warm and not to get into the should you, could you will not be running when you drive. Travel mode was one of the questions I specifically asked and the Furrion rep said the anti freeze protection is not available while driving. From what I have seen Truma is the only one that has a travel mode anti freeze option with their optional 12VDC heater/pump assembly.

**Second Chance** · 02-08-2024, 08:55 AM

Originally Posted by Nuffsaid

I guess I made a poor assumption that these tankless heaters are propane, but if it is located under the sink I would assume it is 110V am I correct? I like to boonedock or camp in my daughters front yard, LOL, I don't like having to rely on electric. I have a small on demand electric water heater in my shop mainly so I can have warm water to wash the grease off of my hands. It works ok but I wouldn't keep up with a shower.

The Furrion on-demand water heaters are LP - not electric. Several brands (Truma, Garard) make on-demand HWHs that have a system with a pump and turn on the burner and circulate water in the HWH when the temp drops below 38 degrees... the Furrion does not as far as I know. The issue is not using the Furion during cold weather - it's what happens when you're not using it in between showers, washing dishes, etc.

Rob