I've browsed through the various threads related to the Furrion tankless water heaters that are now standard on 2021 Reflection fifth wheels, but didn't find anyone discussing the question I have concerning these systems.

My question is does anyone have any experience or had any issue using the Furrion tankless water heater in freezing weather conditions?

I just purchased a new 340RDS and have all of two night use under my belt, both of which happen to be driving back home after the purchase (I purchased it out of state). So, since I've used it now, the system has water in it and is no longer winterized. I am back home now and I'm plugged into 110.

We are planning a trip in a week or so and have a couple of days of freezing weather in the forecast where I live, so rather than winterize the unit again, I thought I would kick the furnace on and turn the tank heaters on to keep everything inside warm enough to prevent freezing over the next few days.

However, being that I don't have any experience with this new tankless system, I was wondering about it's freeze protection (or lack thereof). I might have made some poor assumptions in the past, but I always operated under the assumption that the "tanked" systems generated enough heat in and around the water heater to protect it (to some degree or another) during mild freezing conditions. However, because the tankless systems are only generating heat when the system is actually generating hot water (i.e. someone is in the shower or using hot water in one of the sinks), I began to wonder if the tankless system is more susceptible to freezing conditions that the tanked systems I'm used to since at least some of the system is exposed to the exterior of the unit with only the thin metal door between it and the air outside, which wouldn't provide any protection to freezing conditions.

When I called Grand Design with my question, they referred me to Furrion. Furrion said, without hesitation, that their system provide no freeze protection and must be winterized if freezing weather occurs. No surprise there. I called Grand Design again and the rep I spoke with the second time said that they don't have any reports of anyone having issues with the tankless system in freezing weather, but that was of little comfort.

It seems to me this tankless system is probably the weak link in the system, at least concerning using the RV in freezing conditions.

I do realize these units are not designed for extreme weather conditions, but Grand Design itself makes the claim that they test their units down to zero degrees and that their "Third party extreme cold testing showed that the Reflection remained functional." "Remaining functional" in my mind means no freeze damage down to zero degrees. There seems to be a disconnect between what Furrion says about the tankless system and what Grand Design is claiming. I realize Furrion isn't going to claim their unit won't be damaged by freezing conditions, but I am wondering...can I take this thing out and be confident it's not going to get damaged if temps drop into the 20s? Right now, I'm guessing no.

I'd love to hear from anyone with experience in these circumstances.