Winterizing tankless water heater

[sparkydave]

Our new 2023 Wolf Pup 14CC has a tankless Furrion water heater, which is new for this model year. Furrion manual says blowing it out with air or running pink stuff through it is OK. Finding some horror stories online of people with freeze-damaged Furrion tankless heaters who tried blowing them out with air and finding out that parts of it hold water and there is no drain. Forest River's manuals don't cover winterizing the tankless ones, only the conventional ones.

I'm inclined to think running pink through it seems pretty straightforward, anything I should do differently?

[dougrainer]

sparkydave wrote:
Many thanks, I'm thinking that's the plan. Blow out, run the pink through it, cross fingers that it doesn't have any new automatic drain ports come spring.

No such thing as automatic drain ports. Even on million dollar motorhomes. Doug

[sparkydave]

Many thanks, I'm thinking that's the plan. Blow out, run the pink through it, cross fingers that it doesn't have any new automatic drain ports come spring.

[dougrainer]

This is the procedure for a 7k Aqua hot on large Diesel motorhomes.

When it’s time to store a motor home for the winter
months or when freezing temperatures are expected, it’s
crucial to properly winterize the Aqua-Hot to avoid serious
damage, requiring a complete system replacement not covered under the Aqua-Hot Limited Warranty Statement. The
process of winterization consists of completely draining the
domestic water from the system and pumping RV winterization antifreeze through to flush out the system.

This is ONLY thru the fresh water system, not the furnace system. I blow out the Aquahot and complete RV system then run RV antifreeze thru the Aqua Hot. Aqua Hot is adamant, that the small 1/8 inch coiled copper tubes in the heat exchanger fluid, even blowing out there will still be droplets than can form and then freeze bursting the coil and requires replacement of the complete Aqua hot. I follow the same procedure on all RV demand water heaters like yours. Demand Water heaters have small coil type heat exchangers and these are how you get fast heat transfer for continuous on demand hot water. So, blow out and then install RV antifreeze thru the Water Heater. If you cannot blow out just drain and then run RV antifreeze thru the Water and Hot water system. Better safe than sorry. Doug

[opnspaces]

I was going to say the same thing except reverse. I would blow it out then pump pink stuff through. Then probably blow it out again for good measure.

[LouLawrence]

You could use the belt and suspenders approach. Pump pink stuff through it and then blow out the pink stuff. Anything left will not freeze and you won't be left with a bunch of pink stuff in the lines.

[sparkydave]

Yeah, the guy doing the walk through seemed excited that the tankless was a new thing, but I'm learning more about it and thinking it's an overly complex and expensive thing that could be a problem child. I found a Youtube on winterizing one, but he was using air. I'm just not convinced that works, especially when the manual indicates it doesn't hold enough water to cause a problem. Key thing: It still holds water after blowing it out, and there's another Youtube of somebody showing how he repaired his after it cracked from freezing despite blowing it out.

[Second_Chance]

There have been reports on other forums that instructions in the Furrion manual are in error and have lead to cracked heat exchangers. You might search YouTube and find someone (a good RV tech) who has uploaded a video on how to winterize one of these water heaters properly. I don't understand why manufacturers (not just Forest River) thought the Furrion on-demand WH was a good idea in an RV...

Rob

[pbeverly]

Furion website has a manual you can download.

https://furrion.com/pages/downloads-climate