Truma combi in winter

[Sparks701]

My sequence was winterized. Can I still run the furnace? Do I need to drain the antifreeze from the truma? Can’t seem to find a definitive answer anywhere. Thanks

[MCP]

Typically the water heater portion would be drained and bypassed for winter. However, I suppose it could have been refilled with antifreeze but I don’t know why. Truma has very specific instructions for draining in their operating manual (see page 14) and they make no reference to filling with antifreeze. They do state the furnace can be operated without the water heater portion but the water in the Truma container would heat up to 160+/- so similarly the antifreeze would. Why not simply do the bypass valves and then drain the Truma? Then you should be good to go.

[Siriusblue]

1) There shouldn’t be antifreeze in the Truma - it should be drained completely and then bypassed for winterizing. Antifreeze can damage the system.
2) Yes, the Truma will heat without water in the system.

[Sparks701]

I’ll have to make sure it was bypassed. Thought I saw a couple videos of people running antifreeze through it. General Rv did the 1st winterizing so I’m not familiar with how that works yet. Thanks for the help!

[Siriusblue]

Here's a quote right from Combi - "Winterizing your RV with a winterizing fluid is only possible with an installed bypass kit, refer to the complete manufactures manual for more details. And remember, the use of high pressure air is not recommended."

Just because there's a video posted doesn't mean it's correct. Also - There are way, way too many bad dealership winterizing stories not be a skeptic. Best to read your manual and check it yourself.

[Sparks701]

Originally Posted by Siriusblue

Here's a quote right from Combi - "Winterizing your RV with a winterizing fluid is only possible with an installed bypass kit, refer to the complete manufactures manual for more details. And remember, the use of high pressure air is not recommended."

Just because there's a video posted doesn't mean it's correct. Also - There are way, way too many bad dealership winterizing stories not be a skeptic. Best to read your manual and check it yourself.

Thanks! Definitely a learning experience. So glad I found this forum. Been a ton of help.

[robertj1961]

Might be worth considering just keeping it winterized and using an electric heater when camping this time of year. We have done this for years and unless extremely cold they work great. Available at Wal Mart etc. and very reasonable price. You just have to keep a check on your electrical system as these set on "high" can pull about 15 amps or so. I usually set mine on a medium setting that only pulls about 900 watts but in the van should provide adequate heat.
We only use our "Combi" for hot water (so far).

We also use this kind of heater in the winter to "assist" in the winterizing process. I personally don't use the antifreeze for anything but I am in North Carolina and temperatures are not the same as they are in other areas. We drain all of the water and "blow out" the lines with low air pressure and have never had freezing problems when using a small heater to keep temperatures a little warmer.

[Sparks701]

I’m in Illinois 11 today and 3 with -25 windchill tomorrow. I think I will stick with the antifreeze out this way. Hopefully late march I can sneak a weekend camping trip in in this area. Prob won’t fill up water lines until mid April.

[robertj1961]

In that case with those temperatures don't blame you! Better to be safe than sorry. We rarely get to single digits but it does happen.

[RonRM]

The winterizing process is sort of convoluted on these things. There are several shutoffs to pay attention to (near the truma, water pump and under the passenger bed near the fresh water tank).

As mentioned, the Truma needs to be isolated from getting any pink stuff inside and it will run the heater without water (obviously not the hot water). At our temps (we are in WI), it won't sip propane like it does in the 40's-60's. If you can get plugged in, an option is space heaters.

I found a document on a FB forum that outlined winterizing a 20L...it was loaded with errors and conflicts. I think there is a YT video that isn't too bad as well. Nonetheless, close enough.

Things to watch out for...

The outside shower water connection - make sure it got winterized; even with heat running, that space doesn't get that warm (no airflow).

The hot water diverter on the shower - you will know if they missed that, the blue thing will crack.

Shower drain - trap needs pink stuff.

Both sink drains and toilet flush path probably all good as running the faucets and flushing takes care of those.

Black tank flush - needs pink stuff

Both city and fill lines- need pink stuff

Did they remove the water filter (big white thing)...if not it needs to be removed or filled once everything else has pink stuff in it.

There are basically three paths - city water, on-board fill and on-board tank via water pump; all need pink stuff.

I'd double check it all...it's not really complicated, but it does have a few extra moving parts vs. my Class A.

It only takes a couple of gallons (I think i used 4 but I like to have a good deal of pink stuff in the black/grey and fresh tanks).

I use two tools, air compressor (with pressure gauge and my RV water pressure gauge just to be sure not to get past 20-25psi), a 6 gallon tank with a 12v pump for pumping pink stuff in the city connection and eventually into the onboard tank.

It's a simple process to pressurize, drain, open/close specific values for the Truma..etc. Just don't forget the shower hot water diverter, and the outside shower.

It's a multi step process to get pink stuff everywhere it needs to go. I use the pump setup hooked into the city fill, onboard tank fill, then another gallon connected into the hose under the passenger bed (pay attention to the valve position in that area). Not complicated, but I'll call it delicate is the black flush...if you pump air or pink stuff into that connection - have someone open the toilet as not to pressurized the black tank.

All that and I still leave the tank heaters on all winter while it's plugged in.

ron

[Sparks701]

Originally Posted by RonRM

The winterizing process is sort of convoluted on these things. There are several shutoffs to pay attention to (near the truma, water pump and under the passenger bed near the fresh water tank).

As mentioned, the Truma needs to be isolated from getting any pink stuff inside and it will run the heater without water (obviously not the hot water). At our temps (we are in WI), it won't sip propane like it does in the 40's-60's. If you can get plugged in, an option is space heaters.

I found a document on a FB forum that outlined winterizing a 20L...it was loaded with errors and conflicts. I think there is a YT video that isn't too bad as well. Nonetheless, close enough.

Things to watch out for...

The outside shower water connection - make sure it got winterized; even with heat running, that space doesn't get that warm (no airflow).

The hot water diverter on the shower - you will know if they missed that, the blue thing will crack.

Shower drain - trap needs pink stuff.

Both sink drains and toilet flush path probably all good as running the faucets and flushing takes care of those.

Black tank flush - needs pink stuff

Both city and fill lines- need pink stuff

Did they remove the water filter (big white thing)...if not it needs to be removed or filled once everything else has pink stuff in it.

There are basically three paths - city water, on-board fill and on-board tank via water pump; all need pink stuff.

I'd double check it all...it's not really complicated, but it does have a few extra moving parts vs. my Class A.

It only takes a couple of gallons (I think i used 4 but I like to have a good deal of pink stuff in the black/grey and fresh tanks).

I use two tools, air compressor (with pressure gauge and my RV water pressure gauge just to be sure not to get past 20-25psi), a 6 gallon tank with a 12v pump for pumping pink stuff in the city connection and eventually into the onboard tank.

It's a simple process to pressurize, drain, open/close specific values for the Truma..etc. Just don't forget the shower hot water diverter, and the outside shower.

It's a multi step process to get pink stuff everywhere it needs to go. I use the pump setup hooked into the city fill, onboard tank fill, then another gallon connected into the hose under the passenger bed (pay attention to the valve position in that area). Not complicated, but I'll call it delicate is the black flush...if you pump air or pink stuff into that connection - have someone open the toilet as not to pressurized the black tank.

All that and I still leave the tank heaters on all winter while it's plugged in.

ron

Very informative and well written. Thanks Ron!

[RonRM]

Glad to pile in...thanks