Vacuum Breaker Valve Replacement, please HELP!

AstralPixel · 05-26-2022, 02:32 AM

Has anyone here replaced their vacuum breaker valve in a 2020 Omni/Magnitude RB34 or similar model (RS36, SV34, etc).

I'm pretty sure my valve is reversed because I can't get my Sani-Flush line to work at all. When I connect the water line to the Sani-Flush I doesn't work at all and sprays water back out when I go to remove the hose. Based on some research on here and online I suspect the breaker valve is the culprit. It is likely reversed.

I'm hoping I can just do a swap myself because I don't feel like driving to the dealership that I bought it from (now a CW) since it is almost 2hrs away.

Has anyone done this or found a detailed tutorial online for these, or similar models. I think it is located behind the shower knobs but would like to confirm before I cut them open.

Thanks and safe travels!

**16ACE27** · 05-26-2022, 03:10 AM

Quote:

Originally Posted by AstralPixel

Has anyone here replaced their vacuum breaker valve in a 2020 Omni/Magnitude RB34 or similar model (RS36, SV34, etc).

I'm pretty sure my valve is reversed because I can't get my Sani-Flush line to work at all. When I connect the water line to the Sani-Flush I doesn't work at all and sprays water back out when I go to remove the hose. Based on some research on here and online I suspect the breaker valve is the culprit. It is likely reversed.

I'm hoping I can just do a swap myself because I don't feel like driving to the dealership that I bought it from (now a CW) since it is almost 2hrs away.

Has anyone done this or found a detailed tutorial online for these, or similar models. I think it is located behind the shower knobs but would like to confirm before I cut them open.

Thanks and safe travels!

There are threads on this forum with Omnis with the same issue and resolution. Not sure if they were the same model as yours though.

AstralPixel · 05-26-2022, 03:42 AM

My saniflush does t seem to be working at all.

1. Connect the water source to the saniflush
2. Open the black tank valve
3. Turn on the water
4. Nothing happens, no more water comes out of the black tank.
5. Turn off the water
6. Water sprays out from the saniflush connection when start to disconnect the water supply.

Water is not making it to my black tank from the saniflush input line.

AstralPixel · 05-26-2022, 03:51 AM

The saniflush doesnt do anything at all. I don't hear any spraying, water running or the like.

I can dump the tanks normally, I just don't seem to be able to flush it out.

Judge · 05-26-2022, 10:15 AM

It’s probably been plumbed backwards. I’ve heard that happening several times from the factory.

The SaniFlush Vacuum Breaker is located in the shower wall behind the shower controls on the SV34.

I’ve replaced my mixing unit with another unit with separate hot and cold controls. I’m not sure you will have enough PEX and room to work and to pull it up to the opening to access it.

If you open the acess panel under the shower, you should see 3 PEX lines…. the hot (red), the cold (blue) and a third that has blue PEX connected to white PVC (this is the water supply to the black tank from). I don’t remeber seeing the vacuum breaker under there so I’m pretty sure it is in the wall.

My old Outlaw 29H also had it behind the shower wall as well. It was bad from the factory and leaked everywhere inside the coach. They cut a square hole in the wall to replace it and then covered the hole with an access panel. You may need to do the same if not under warranty.

abjbrtd · 05-26-2022, 01:06 PM

Greeting and Welcome

I used the "advanced search" for vacuum breaker

Here's 1 result.
https://www.thorforums.com/forums/f4...ker-30335.html

Looks like Bob has it removed in his picture

AstralPixel · 05-26-2022, 01:10 PM

@Judge - Do you know if you can access and repair it by removing the shower controls, or do you need to cut a hole in the wall.

I think I am still under warranty for the next few weeks but I'd rather not go through the hassle of taking it in if it is something I could do myself.

AstralPixel · 05-26-2022, 01:26 PM

@abjbrtd - Thanks! I actually did use the search feature and found that exact post. I generally understand what the problem is but I'm looking specifically for anyone who has replaced it on an RB34 or closely similar model.

As @Judge said in his response to that post, and on this thread, he *thinks* he can access it through the shower diverter, or shower wall. I'm looking for someone who has actually done this with one of these modes to see if this is something I should attempt vs taking it in.

For instance if I in fact need to cut a whole in the wall I'd rather take it in since they will probably know exactly where to cut the hole (or at least better than me) but if I can just remove the diverter and repair/replace the valve, I think I could handle that.

**EA37TS** · 05-26-2022, 04:33 PM

In most rigs the vacuum breaker is under the bathroom sink. Open the cabinet and look up in the rear corners. Three rigs, three manufacturers and it has always been in the same spot. Usually requires a contortionist to replace it.

Judge · 05-26-2022, 08:39 PM

Quote:

Originally Posted by EA37TS

In most rigs the vacuum breaker is under the bathroom sink. Open the cabinet and look up in the rear corners. Three rigs, three manufacturers and it has always been in the same spot. Usually requires a contortionist to replace it.

Not on the Omni / Magnitudes or the Class C Outlaws. I can attest to that from owning both those rigs.

Judge · 05-26-2022, 08:47 PM

Quote:

Originally Posted by AstralPixel

@abjbrtd - Thanks! I actually did use the search feature and found that exact post. I generally understand what the problem is but I'm looking specifically for anyone who has replaced it on an RB34 or closely similar model.

As @Judge said in his response to that post, and on this thread, he *thinks* he can access it through the shower diverter, or shower wall. I'm looking for someone who has actually done this with one of these modes to see if this is something I should attempt vs taking it in.

For instance if I in fact need to cut a whole in the wall I'd rather take it in since they will probably know exactly where to cut the hole (or at least better than me) but if I can just remove the diverter and repair/replace the valve, I think I could handle that.

There is a rectangular opening behind the shower mixing valve for the plumbing connection. I am 100% sure it is just under that opening behind the shower on the SV34. The challenge will be that there is only a small amount of excess PEX and it is not very flexible. There is PEX also connected to PVC under the shower floor from one end of the Vacuum Breaker to the black tank.

You might get lucky taking off the mixing valve and trying to pull back the shower back splash enough to access it that way. Just take care you don’t crack it.

Now as I recall the RB34 has two bathrooms and the shower is in the rear so it is possible the RB34 has it located elsewhere; especially with two black tanks.

Check the plumbing schematics for the RB34. Also just remove the access panel under the shower floor. If you see a white PVC pipe, the VB is behind the mixing valve most likely.

ducksface · 05-26-2022, 09:02 PM

Some of us carry short pieces of pex and sharkbite connectors for quick repairs.

Sharkbite push to connect connectors
are your dear friend in cramped quarters.

If my suggestion is a latitude that shouldn't have been mentioned,
Management will please take this post down.

AstralPixel · 05-27-2022, 10:32 PM

I called Thor technical service. The agent was great and able to quickly locate the valve.

For the record on a 2020 Thor Omni RB34 (or mine anyway) the check valve is located in an access panel in the cabinet above the toilet. See attached photos.

Does anyone know if that valve needs to sit vertically like it is in the 2nd photo. I just reversed the valve in the 3rd photo but I dont want to test it out before checking here.

**EA37TS** · 05-27-2022, 10:42 PM

Quote:

Originally Posted by AstralPixel

I called Thor technical service. The agent was great and able to quickly locate the valve.

For the record on a 2020 Thor Omni RB34 (or mine anyway) the check valve is located in an access panel in the cabinet above the toilet. See attached photos.

Does anyone know if that valve needs to sit vertically like it is in the 2nd photo. I just reversed the valve in the 3rd photo but I dont want to test it out before checking here.

No one can answer your question unless they see where the other ends of the lines come from or go to.

Reverse it and try. If the flush still doesn’t work it could be a bad valve.

As a note, some tank flush problems are the result of the tank nozzle holes being too small causing them to get clogged with crap. The solution to that problem is to remove the nozzles and drill the holes 1/64th larger. Had that issue on a class c about 12 years ago.

**16ACE27** · 05-28-2022, 01:38 AM

Quote:

Originally Posted by AstralPixel

I called Thor technical service. The agent was great and able to quickly locate the valve.

For the record on a 2020 Thor Omni RB34 (or mine anyway) the check valve is located in an access panel in the cabinet above the toilet. See attached photos.

Does anyone know if that valve needs to sit vertically like it is in the 2nd photo. I just reversed the valve in the 3rd photo but I dont want to test it out before checking here.

It's not gravity operated so valve orientation is not a concern.

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