Drained water heater & now too much pressure? Water Heater Check Valve Problem?

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Drained water heater & now too much pressure? Water Heater Check Valve Problem?

February 07, 2019, 06:24:07 pm

Today I drained and flushed my water heater like I have done many times in the past. After draining and flushing the water heater, I closed the pressure relief valve and cut the water pump on to fill the water heater. Then I turned the water heater on just to make sure I had everything okay everything seemed to be fine. A bit later I turned the water pump off and flushed the toilet because I wanted all the water out of the toilet in order to clean the seal around the ball.

Then the interesting thing happened, the water kept running. Typically with the water pump off and no city water it'll run maybe 5 or 10 seconds, I'm guessing from the water in the lines. But it kept running a little slower than normal but it was running it even started running hot (in the toilet) I double checked my 2 water sources (pump and City water), neither were on.

I've tried flipping the pressure relief valve as mentioned in the manual for leaks of that valve.

I'm stumped. It appears to be using the water heater as a third source of water??? Or else the water heater had so much pressure it's pushing it back into the lines???

I move on Monday to Gulf Shores, AL and have already gotten the name of a mobile RV guy just in case I can't figure it out.

Any suggestions??
Pam

Re: Drained water heater and now too much pressure?

Reply #1 – February 07, 2019, 07:13:00 pm

Sounds like the water heater's cold water inlet check valve is bad and letting hot water migrate back into the cold water side.
The RV Doctor: RV Water Heater Check Valve - What For?

Larry

Re: Drained water heater and now too much pressure?

Reply #2 – February 07, 2019, 08:20:05 pm

Thanks, that makes sense. I am wondering if while I was flushing the water heater I got to aggressive and some of the mineral deposits got into the valve??

I'm thinking if I caused it by flushing the tank, maybe I can fix it by flushing the heater again?? I might be dreaming, but it won't cost anything to try.

I'll try that tomorrow, if that doesn't work I'll look into replacing it.

Thanks again.
Pam

Re: Drained water heater and now too much pressure?

Reply #3 – February 07, 2019, 10:21:48 pm

Quote from: pstravus - February 07, 2019, 08:20:05 pm

Thanks, that makes sense. I am wondering if while I was flushing the water heater I got to aggressive and some of the mineral deposits got into the valve??

I'm thinking if I caused it by flushing the tank, maybe I can fix it by flushing the heater again?? I might be dreaming, but it won't cost anything to try.

I'll try that tomorrow, if that doesn't work I'll look into replacing it.

Thanks again.
Pam

Pam, what year and model Lazy Daze do you have?

Chris

Re: Drained water heater and now too much pressure?

Reply #4 – February 07, 2019, 11:13:28 pm

Quote from: pstravus - February 07, 2019, 06:24:07 pm

Today I drained and flushed my water heater like I have done many times in the past. After draining and flushing the water heater, I closed the pressure relief valve and cut the water pump on to fill the water heater. Then I turned the water heater on just to make sure I had everything okay everything seemed to be fine. A bit later I turned the water pump off and flushed the toilet because I wanted all the water out of the toilet in order to clean the seal around the ball.

How did you insure that the water heater tank was refilled before turning the water heater back on? Most people leave the relief valve open until water starts coming out and then close it. This also insures that the proper air gap is created at the top of the tank. If the relief valve was closed before turning the pump on, a hot water tap should be open until water comes out. Otherwise the tank could be mostly filled with air.

Art

Re: Drained water heater and now too much pressure?

Reply #5 – February 08, 2019, 12:29:25 am

Pam,

Some people have used a borescope / inspection camera to see inside their tanks (when empty) to check if they got all the deposits out. But I don't know if it could see tiny deposits in the check valve.

Jane

Sent from Yahoo Mail for iPhone

Re: Drained water heater and now too much pressure?

Reply #6 – February 08, 2019, 12:48:21 am

Quote from: JandS2 - February 08, 2019, 12:29:25 am

Some people have used a borescope / inspection camera to see inside their tanks (when empty) to check if they got all the deposits out. But I don't know if it could see tiny deposits in the check valve.

The check valve is located outside of the water heater tank, it would not be visible from inside the tank.
If you can find it, it can be removed and blown out, hopefully ejecting what ever is holding the check valve open.
It looks something like this.
Amazon.com: Aqua Pro (20818) 1/2" x 1/2" Lead Free Male Check Valve: Automotive

Art's suggestion that the pressure relief valve wasn't open during the refill would explain the extended flow, with the water pump off.
Try opening the relief valve, with the water pump on, and see if that helps.

Larry

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Re: Drained water heater & now too much pressure? Water Heater Check Valve Problem?

Reply #7 – February 08, 2019, 01:31:11 pm

Thanks for all the info. I have a 2008 MB, so the water heater is under the passenger bed, but I can see it by pulling a wardrobe drawer. I saw a silver thing,(?) that I thought might be it but most pics I see are Brass. I'll look again if it doesn't work after using the suggestion of opening the PRT and filling until water comes out.

I believe I closed the PRT before filling the water heater yesterday. I decided the water heater was full when the pump quit running.

I am about to refill it with the PRT open until water comes out. Then I will close it and continue filling until the water pump turns off. I'll let you guys know what happens.

Re: Drained water heater & now too much pressure? Water Heater Check Valve Problem?

Reply #8 – February 08, 2019, 03:35:21 pm

Update -
I drained, flushed again, filled the water heater up untill water came out the relief valve, closed the relief valve and finished filling the heater.

The water is still running too long with the pump off. Just to double check, I turned the water heater on, left it on till it cut off, turned the water pump off and flushed the toilet. Once again, more water ran than I should get and it's hot.

So based on what you guys said and what I looked up online it does sound like the cold water check valve.

Do you guys see any problems with using it as is for a few days? When I turn the water pump on, the facuets seem to be normal. When I turn the faucets off the water pump runs for a few seconds perhaps a bit longer than normal I'm not sure. If you think it could mess something up I can easily live off water from jugs for a few days. I've done it for about a week once before while waiting on a water pump!

Thanks again for everyone's help. This group is great!!

Pam

Re: Drained water heater & now too much pressure? Water Heater Check Valve Problem?

Reply #9 – February 08, 2019, 03:52:06 pm

Please correct me if I'm wrong, but in a MidBath I thought the water heater to be directly under the drawers under the closet. The spare tire was located in the forward portion of the starboard storage compartment under the bed/couch. The one I had was a 2001 MB.
Maybe someone replaced the brass valve check valve with a stainless one: 1/2 inch Stainless Steel Spring Check
I wouldn't use the water heater unless you need it. The hot water shouldn't actually hurt anything in the plumbing or toilet though. RonB

Re: Drained water heater & now too much pressure? Water Heater Check Valve Problem?

Reply #10 – February 16, 2019, 03:32:26 pm

So I have a mobile repair quy here working on this. According to them I do not have a check valve. I also looked and could not see one. I have seen pictures online of how they look installed, so I think I know what I was looking for. But they are installing one. They said some older rigs do not have one. Mine is a 2008 MB.

I don't know if this is the correct thing to do, but it's what I'm doing. I still don't understand how it seemed to work correctly for 10+years without a check valve. Until after flushing the hot water heater all of a sudden I was getting too much water running from the spigots when no city water or water pump off (what I originally called too much pressure) and I was getting hot water in my toilet..?.

Anyone with a 2008 or older rig have a check valve that was installed by the factory?

I'll let you know how everything goes once they are finished.

Pam

Re: Drained water heater & now too much pressure? Water Heater Check Valve Problem?

Reply #11 – February 16, 2019, 06:10:43 pm

Quote from: pstravus - February 16, 2019, 03:32:26 pm

Anyone with a 2008 or older rig have a check valve that was installed by the factory?

Our 2003 FL has one.
It looks like the one I linked to an earlier in the thread.

Larry

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