Water heater fitting bursted off tank 10 minutes after showering

[Bobdole]

Using a water pressure regulator with lower pressure 40psi. Nothing out of the ordinary. Wasn’t using propane, only electric. Wife heard a loud pop, water pouring all over the rv floor. I ran around cut off the city water. Took the water heater panel off inspected the connections. Sure enough the small white plastic piece separated from the threaded fastener it plugs into. It plugs back in and holds pretty well so it isn’t broken. The picture shows it connected back. It was completely off the grey piece you turn. Can I replace this with a brass fitting? Found a few on Amazon that look to be the same as this cheap plastic piece. Want to try and avoid this happening again. Ive had to pull out a few water logged particle board pieces from under the water heater already. Thanks.

[Campnjoe]

You mean the grey twist-on was still attached to the pipe threads but the white 90 degree on the pex popped off?

Wow, never heard of that one before. On mine, three of the grey twist-ons were loose. Just had to snug them up good and have been fine ever since.

[Bobdole]

Originally Posted by Campnjoe

You mean the grey twist-on was still attached to the pipe threads but the white 90 degree on the pex popped off?

Wow, never heard of that one before. On mine, three of the grey twist-ons were loose. Just had to snug them up good and have been fine ever since.

Yep. I had the same issue. Snugged mine up was good all last year. Just happened randomly, I’d replace them if you have the same setup to avoid it. Was a mess.

[Campnjoe]

Originally Posted by Bobdole

Yep. I had the same issue. Snugged mine up was good all last year. Just happened randomly, I’d replace them if you have the same setup to avoid it. Was a mess.

I wonder if you didn't have some type of high pressure event.

[Bobdole]

Originally Posted by Campnjoe

I wonder if you didn't have some type of high pressure event.

I don’t think so. Was at a buddy site, neighbor had the same regulator. Nobody around me had any issues. You’d think the grey piece would be over the lip of that white elbow piece to secure it better in some way. You can just grab it and pull, pop it right off. It looks like the others are the same. Maybe that one was defective somehow but it worked fine for at least 10 trips last year.

[cavie]

did the white and gray pieces separate or did the gray come off the threads?

[Bobdole]

Originally Posted by cavie

did the white and gray pieces separate or did the gray come off the threads?

White and grey pieces separated. Grey piece was still attached to the heater and tight. White piece just shot off of it very hard.

[cavie]

Originally Posted by Bobdole

White and grey pieces separated. Grey piece was still attached to the heater and tight. White piece just shot off of it very hard.

That is strange.

[javelin]

I was also wondering if maybe the hot water tank pressurized too much and the tank safety valve did not purge the pressure. It is usually a good practice to open the safety valve in Spring when doing the de-winterization flush to make sure it is physically operational at least and not rusted or corroded shut etc.....WHEN the hot water tank is NOT ON and NOT HOT. Severe burns could result otherwise. The other thing I was wondering is if the pex line is putting pressure on the right angle fitting to break loose from the tightening body fitting as well? Sometimes when using metal adapters people tend to over tighten and damage other weaker plumbing components. An example of this is people that use a metal hot water tank plug instead of the plastic one that came with the coach.....not realizing that the tank and drain threads are only aluminum (does not require an anode rod like a steel tank does) and the threads of the tank are potentially damaged.

[JimOIB]

Bottom line up front - replace the fitting.

Just looking at the picture it appears the fitting is deformed. The gray threaded piece looks like it expanded and is not holding the white elbow in place correctly . It could have been caused by a defective fitting from the get-go and it decided to fail. It could have been caused by the connection being too tight on the water heater. It could have been caused by a pressure build up which is normal and caused the fitting to fail before the T&P valve opened. It could have been caused by the water heater overheating due to a bad thermal cutoff and expanding the connection between the gray and white parts. Regardless, replace the fitting. You should be able to find a brass fitting at a big box hardware store.

[Bobdole]

Originally Posted by jimbo12

Bottom line up front - replace the fitting.

Just looking at the picture it appears the fitting is deformed. The gray threaded piece looks like it expanded and is not holding the white elbow in place correctly . It could have been caused by a defective fitting from the get-go and it decided to fail. It could have been caused by the connection being too tight on the water heater. It could have been caused by a pressure build up which is normal and caused the fitting to fail before the T&P valve opened. It could have been caused by the water heater overheating due to a bad thermal cutoff and expanding the connection between the gray and white parts. Regardless, replace the fitting. You should be able to find a brass fitting at a big box hardware store.

Yep have some brass fittings on order. I was originally asking if it was ok to use brass but sounds like it’s ok. I did have the grey pieces pretty tight btw. I had experienced leaks until they were tightened down pretty hard by hand. I’m hoping the brass fixes this crap. That was something I never want to see happen again lol.

[Beau388]

Originally Posted by Bobdole

Using a water pressure regulator with lower pressure 40psi. Nothing out of the ordinary. Wasn’t using propane, only electric. Wife heard a loud pop, water pouring all over the rv floor. I ran around cut off the city water. Took the water heater panel off inspected the connections. Sure enough the small white plastic piece separated from the threaded fastener it plugs into. It plugs back in and holds pretty well so it isn’t broken. The picture shows it connected back. It was completely off the grey piece you turn. Can I replace this with a brass fitting? Found a few on Amazon that look to be the same as this cheap plastic piece. Want to try and avoid this happening again. Ive had to pull out a few water logged particle board pieces from under the water heater already. Thanks. Attachment 30211

I add my "two cents" worth of advice. You have an aluminum tank, so no brass, steel or copper next to aluminum. Water with dissolved salts and dissimilar metals cause galvanic corrosion. The fitting is called a right angle swivel. Lowes carries them in the Sharkbite brand and the should handle 150 psi. If you are worried about the same failure then use a standard right angle adapter, pipe thread to PEX. It appears that Thor used PEX type B so make sure your fittings and clamps are suitable for the type of PEX you have.

[Bobdole]

Originally Posted by Beau388

I add my "two cents" worth of advice. You have an aluminum tank, so no brass, steel or copper next to aluminum. Water with dissolved salts and dissimilar metals cause galvanic corrosion. The fitting is called a right angle swivel. Lowes carries them in the Sharkbite brand and the should handle 150 psi. If you are worried about the same failure then use a standard right angle adapter, pipe thread to PEX. It appears that Thor used PEX type B so make sure your fittings and clamps are suitable for the type of PEX you have.

Gotcha. Isn’t brass to aluminum ok though? I thought it was stainless to aluminum that was bad.

[Beau388]

Originally Posted by Bobdole

Gotcha. Isn’t brass to aluminum ok though? I thought it was stainless to aluminum that was bad.

Aluminum has galvanic potential of -1.67 volts, steel -0.44 volts, yellow brass -0.350 volts and copper +0.34 volts. That means all the metals listed will corrode aluminum. How fast is dependent on - how acid the water, how hot the water and the voltage potential.

[Pete'sMH]

But you can use a plastic hex coupler in the tank which doesn’t appear to have failed and then any pipe connector you want. And in any case plastic/nylon is fine for domestic hot water. It’s been used for decades and you’ve almost certainly got same connecting your house faucets. It wouldn’t surprise me in the least if you just had a cheap Chinese fitting that failed for being cheap. Buy new parts at the big box store and put it back together again and you should be fine.

[JimOIB]

If your water heater is like mine then there is a brass check valve connected to the aluminum tank. The hot water to the coach is then connected to the check valve. If that is the case then brass will work fine.

[Bobdole]

Originally Posted by jimbo12

If your water heater is like mine then there is a brass check valve connected to the aluminum tank. The hot water to the coach is then connected to the check valve. If that is the case then brass will work fine. Attachment 30229Attachment 30229

Yep. We ended up putting brass fittings on both the water heater and going in and out of the pump. Dealer said they would just put the plastic back in. I don’t trust them regardless of what they all currently use. If I find more I’ll be replacing them as well. Be warned, at least for the elbow type if you have them.