NO HOT WATER! Water back flow preventer valve failure. What I found.

Topsail · 06-29-2019, 09:38 AM

This post may help others. It's mainly to pass along information for anyone with a similar issue.

RV is hooked up to city water with no water pressure regulator. Everything was fine. Decent flow from both cold and hot water at kitchen sink, bathroom sink and shower.

The city discovers a leaking water main across from our home. They make a repair. I notice an increase in the water pressure but didn't install a water pressure regulator. Bad mistake!

Next day I notice a higher water level in the toilet but just think the wife has left more in than normal after use.

Not long thereafter we lose all hot water flow from any faucet. I get under the RV and remove the access panel for the hot water tank. It's hot so I know the element is on and determine it must be a restriction in the outlet from the tank.

I turn off the hot water heater and later drain the tank. Next I remove the back flow preventer valve. After removing these Pex fittings I discover the small valve and spring were dislodged and in the elbow down line from the valve. The tiny valve looks like a white golf tee. Anyway, I buy a replacement valve and splice in some new Pex hose with Sharkbite fittings. Yes, I was a little nervous because any failures here would mean a lot more work running new Pex hoses.

This valve replacement worked great. No leaks and now we have hot water. I still didn't think to install the water pressure regulator so that night the toilet did overflow a little. Some did get onto the carpet so I used towels to get it up and then I used the 90% rubbing alcohol trick to clean it and help dry. The alcohol worked great. No smell and dry as a bone.

Thinking back about what happened with the damaged back flow valve on the hot water tank and the toilet valve leaking I realized it had to be the higher water pressure on the city line. I installed an inexpensive non adjustable flow regulator from Walmart and later ordered an adjustable one from Renator that I like.

Now everything works as it should. Lessons learned.

The back flow preventer valve is the straight fitting between the two 90* elbows coming off of the hot water tank. Pictures attached.

Sue46 · 06-30-2019, 06:47 AM

Good to know. We tend to always use a pressure regulator. We wer in one CG that had 150 lb. prssure and no signs telling you this.

What is the 90% alcohol tridk?. I never heard of that one before.

Topsail · 06-30-2019, 07:16 AM

Even with the cleanest toilet any overflow will have trace amounts of bacteria that just smells especially in carpeting. You have to kill this to eliminate odors. You have to soak up as much water as possible and then liberally apply the alcohol. It kills the odor and drys very fast. You can add fans to help dry.

I didn't like the idea of pouring anything onto the carpet and getting the substrate wet too, but that's how it's done and it works. This trick is specific to a toilet overflow. For other accidents there are other things to use. I'd give credit where due, but forgot where/who offered it (web).

Sue46 · 06-30-2019, 07:23 AM

Thanks

Mykaen · 07-02-2019, 10:23 PM

Quote:

Originally Posted by Topsail

Next day I notice a higher water level in the toilet but just think the wife has left more in than normal after use.

Was this in the bowl or the tank?

Quote:

Originally Posted by Topsail

I installed an inexpensive non adjustable flow regulator from Walmart and later ordered an adjustable one from Renator that I like.

Did you put this inline beyond your city water port or just attached to your hose?

This past weekend was my first outing with an RV with plumbing. I'm concerned I may have a similar issue. My tanks are getting more full than I expected. It could just be I underestimated how much we use, or the indicators are faulty. But I feel we are slowly dripping into the tanks somehow.

Topsail · 07-03-2019, 08:40 AM

The high water was in the bowl since the higher pressure was causing the fill valve to leak a little.

Also, the water regulator valve is hooked up at the supply and then the hose to the RV.

There can be many reasons the holding tanks can fill at a fast rate. Most of them come from us new folks just learning to follow best practice.

Mykaen · 07-04-2019, 09:05 PM

Thanks for your response.

So the black water tank was filling and overflowing past the flush portion of the toilet.

I was considering putting the regulator on the inside of the city water port. That would probably be more work than I am interested in at this point. Sadly I didn't realize about the regulator until a friend brought it up about 3 days into t a 4 day trip. It's now on the checklist.

It's also now on the short list to troubleshoot at the next outing. I'll keep your post saved.

Thanks for posting this.

peggwn · 07-07-2019, 08:46 PM

Topsail, Did you have to remove the heater or did the access panel give you plenty of room to work with? I had to get a very small person with strong arms and hands to get a wrench on the valve to get it off and replaced; otherwise it was remove the whole thing to get access.

Topsail · 07-08-2019, 07:32 AM

Fortunately my access panel gave me enough room to get after it with both arms. So the water heater remained in place. I knew I should have taken a picture of that panel for the record. I would estimate the panel is about 9" high by 18" long.

I don't know if this was the original cut out or if the previous owner had enlarged it. It was apparent that someone had worked on the water heater before. The cover for the element wiring was not in place. I believe my cut out was original to my RV.

peggwn · 07-09-2019, 08:03 AM

Thanks, Topsail. Just curious because of the extremely tight access to the back of mine. They location and fitting obviously was not intended for future maintenance or repairs.