Winterizing Thor Magnitude (help)

[thehotarc@yahoo.com]

Any one that could shed a little light on the process for winterizing Magnitude/omni motorhome it would be appreciated. I see low point drain sticker in wash bay by the hose connection that I think is for the black tank. ???

[kwplot34]

You can use the outdoor shower to drain the system and if you look to the left you should also see a blue and a red water line with a valve in them.
Put shower head on the ground and open the cold and hot controls. On the red and Blue line open both valves, go inside and turn on the hot and cold on the kitchen sink, bathroom sink and shower, water will drain out of the the outside lines.
Make sure you have the water pump off and not hooked to shore water.

[thehotarc@yahoo.com]

Thanks bud. I work on stuff and build stuff for a living so I can usually figure stuff out but there's nothing in the manual (its useless), couldn't find it online or YouTube, the Thor magnitude video (1hour orientation video) didn't cover it, and I bought it from the original owner (2 months old) so don't have a dealer to talk to.

[kwplot34]

Originally Posted by thehotarc@yahoo.com

Thanks bud. I work on stuff and build stuff for a living so I can usually figure stuff out but there's nothing in the manual (its useless), couldn't find it online or YouTube, the Thor magnitude video (1hour orientation video) didn't cover it, and I bought it from the original owner (2 months old) so don't have a dealer to talk to.

No problem, happy to help.
The manual is very generic for RV's and cover a wide range of RV.
If you want to pump RV antifreeze through the system let me know it is pretty simple and to access where you hook up is under the bed.

[CTRvs666]

I live in the desert and just have to keep a space heater going in the winter, We get into the 20's at night but 50-60 in the day. So in 10 years of RV's I've never had to winterize and have had no issues.

Until now. I have to take my SG32 up to SLC for a week in service and it is much colder up there. So I am going to winterize the coach today. The only thing I am worried about is the tankless water heater. I understand they can be tricky to drain. What is the procedure for doing that?

[kwplot34]

Originally Posted by CTRvs666

I live in the desert and just have to keep a space heater going in the winter, We get into the 20's at night but 50-60 in the day. So in 10 years of RV's I've never had to winterize and have had no issues.

Until now. I have to take my SG32 up to SLC for a week in service and it is much colder up there. So I am going to winterize the coach today. The only thing I am worried about is the tankless water heater. I understand they can be tricky to drain. What is the procedure for doing that?

Open the outside panel on the tankless and there is an on/off switch, turn it off so you don't accidentally run it without water and open the hot water low point drain and just drain the system.

[CTRvs666]

Originally Posted by kwplot34

Open the outside panel on the tankless and there is an on/off switch, turn it off so you don't accidentally run it without water and open the hot water low point drain and just drain the system.

I am going to pump the pink stuff but after doing so, should leave the valves closed to the empty fresh water tank? A youtube video said to open them back up after the pumping--but that doesn't make sense for backflow reasons. I just have to remember to open them up later. Also, is there a better way to drain the fresh tank other than the outside shower? The Thor video said to use the outside show to drain it. thanks

[kwplot34]

Originally Posted by CTRvs666

I am going to pump the pink stuff but after doing so, should leave the valves closed to the empty fresh water tank? A youtube video said to open them back up after the pumping--but that doesn't make sense for backflow reasons. I just have to remember to open them up later. Also, is there a better way to drain the fresh tank other than the outside shower? The Thor video said to use the outside show to drain it. thanks

Yes, under the bed their is a PVC pipe coming out of the fresh water tank with a ball valve, mine has a red handle on it to turn, turn the handle and the water will empty out of the fresh water tank.
After pumping antifreeze through the system I leave the valve to the fresh water tank closed, like you said just have to remember to open it next spring, and if you forget the lack of water flow from the pump will remind you real fast.

[thehotarc@yahoo.com]

Thanks for all the info guys! I still could not find the red and blue lines with valves. Today a friend was over and we were looking under the outdoor sink because it bleeds back from gray tank(at least its not black tank) the sink will have an inch or two off water in it even if minimal gary water in gray tank! Anyhow low and behold just to the right (accessing from the sponge door) there is a red and blue line going straight down out the floor with ball valves in under sink compartment. ����*♂️��

[Jimbo56]

Originally Posted by thehotarc@yahoo.com

Thanks for all the info guys! I still could not find the red and blue lines with valves. Today a friend was over and we were looking under the outdoor sink because it bleeds back from gray tank(at least its not black tank) the sink will have an inch or two off water in it even if minimal gary water in gray tank! Anyhow low and behold just to the right (accessing from the sponge door) there is a red and blue line going straight down out the floor with ball valves in under sink compartment. ����*♂️��

Glad you found the valves. And I don’t have your model coach. But grey water bleeding into a sink is worrisome.

[Zenith]

We have a different floorplan Magnitude (RB34). It gets down to below 0F here in Northern NM and we still winter camp so we winterize with pressurized air on the supply and antifreeze on the drains so dewinterization is easy. My process may not apply to all the Magnitude / Omni Super-Cs, but may be helpful:

• Turn off the pump, switch off the hot water heater, switch off the icemaker
• Drain black / grey / fresh tanks, leave the fresh tank drain valve open
• Drain the two low spot ball valves for hot and cold, leave them open
• Open every single faucet and leave them open - don't forget to open the hot water heater's high pressure valve to drain it, don't forget to open the outdoor kitchen faucet and the outdoor shower, don't forget to hold flush until no more water comes out

Drive home from camp or the dump site. The movement will drain a lot more water out. At home:

• Dump antifreeze in each ptrap - kitchen sink, outdoor sink (and run the macerator / pump switch), bathroom sink, shower, toilet - for all err on the side of more so some ends up in the grey and black tanks
• Dump antifreeze in the washer/dryer and the dishwasher
• Close up all valves and fixtures
• Hook up the air compressor and set it to 25 PSI, use the hose adapter to thread the compressor to the water inlet (not the tank, the hose bib one for city water)
• Go from highest altitude to lowest opening faucets and running appliances. Do one at a time to make sure air squirts any residual water out. My order:
  • Icemaker (and listen to it sputter)
  • Start a cycle on the washer/dryer till no water comes out then run a spin cycle to drain
  • Shower
  • Bathroom sink
  • Kitchen sink
  • Dishwasher till no water comes out then run a drain cycle to drain
  • Hot water heater high pressure valve
  • Outdoor kitchen sink
  • Outdoor shower
  • Two ball valves for the hot and cold
  • .... THEN REPEAT each the above to be sure

Disconnect the air compressor and leave every faucet open with all the appliances off. It sounds onerous but takes under 15 minutes once you've done it a dozen times.



Since no supply lines have antifreeze, there's no dewinterization. When we're going out for a weekend, we just close it all up and fill up the fresh tank. It makes weekend trips easier and faster to just gogogo!