Okay, I finally got around to replacing the check valve on the hot water side of my heater. For months we have had problems with no hot water. Sometimes fine for weeks, then it goes out. We would get a trickle of water of no water, or sometimes half pressure, etc. In order to fix this, I would turn the water heater bypass valve back and forth a couple of times and usually get it working after one or two tries. I put the new check valve in today and wouldn't you know when I went to take a shower.... NO HOT WATER!! I had to turn the bypass valve to get it working. What else could this be? I also notice a groaning coming from the tank or the plumbing near the tank when running water, cold and hot. I don't know if this is tied together. When the hot water goes out like this, the cold water continues to work as normal. Any ideas what this could be? Should I just go back and install the old check valve with the guts removed?( When I took the old one off, it was busted apart and fell out in my hand. Frustrating!!! It was not easy to get this job done. Any ideas?
Hot Water Heater Output Problem
- Thread starter bigpemby
- Start date
The friendliest place on the web for anyone with an RV or an interest in RVing!
If you have answers, please help by responding to the unanswered posts.
If you have answers, please help by responding to the unanswered posts.
Molaker
Well-known member
I guess it could be crud in the tank. Did you drain it this winter? If not try draining and flushing.
Gary RV_Wizard
Site Team
Maybe the bypass valve is bad too? If it closes, even partially, you don't have cold water going into the tank, so no hot comes out.
I have drained and flushed the tank. I just installed a new bypass valve as part of this job. The old one had a crack in it that worried me. So that doesn't seem to be the problem. There is a check valve on the cold side too. Could that be causing a problem? The cold water always works fine, but then again the cold water has to get past the check valve to push hot water out the top so maybe its causing a problem too? Am I thinking correctly?
boatbuilder
Well-known member
Sounds like you are on the right track. If the tank had a lot of scale in it it could have lodged in the inlet check valve. If it has a rubber seat the scale could get embedded in the rubber and not clear out easily.
RLSharp
Well-known member
You might try removing the stem on the shower hot water valve. Often crud from the water tank accumulates in the stem mechanism and sporadically causes a partial or total blockage of the valve.
Remove the stem clean it good and then with the stem out, turn your water pump on for a couple of seconds with a towel over the stem hole. You might be amazed at what washes out. Good luck and let us know how you make out.
Richard
Remove the stem clean it good and then with the stem out, turn your water pump on for a couple of seconds with a towel over the stem hole. You might be amazed at what washes out. Good luck and let us know how you make out.
Richard
Gary RV_Wizard
Site Team
The cold water at the tap does not go through the water heater lines at all, so cold will run fine. The cold inlet to the water heater just refills the tank as hot water is drawn out and supplies the water pressure that pushes the hot water out when you open a hot tap.
Yes, there could be a cold inlet check valve too. Some manufacturers install them while others do not. It would be unusual for an inlet check valve to stick closed, but anything can happen. You can check this by opening the PT relief valve on the outside of the tank (don't do it while the water is hot - you could get scaled!). If there is no or limited cold water inlet, you won't get a steady flow of water from the relief valve. If water flows out under steady & continuous pressure, then the inlet is fine. You will probably get wet doing this, however.
Did you drain and flush the tank? It is conceivable that the new check valve got immediately crudded up with gunk from the tank. You might want to pull it out and check it.
Yes, there could be a cold inlet check valve too. Some manufacturers install them while others do not. It would be unusual for an inlet check valve to stick closed, but anything can happen. You can check this by opening the PT relief valve on the outside of the tank (don't do it while the water is hot - you could get scaled!). If there is no or limited cold water inlet, you won't get a steady flow of water from the relief valve. If water flows out under steady & continuous pressure, then the inlet is fine. You will probably get wet doing this, however.
Did you drain and flush the tank? It is conceivable that the new check valve got immediately crudded up with gunk from the tank. You might want to pull it out and check it.
Harry B
Well-known member
I believe there are two check valves. in the system One on the input and one on the output of the HW heater. Have you replaced both of them?
Molaker
Well-known member
Is your by-pass valve a single control or do you have 3 separate valves for winterizing? If you have the single control type, the valve could be the problem - maybe junk lodged in it???Gary RV Roamer said:
Thanks to everyone for your help. There was in fact a check valve on the cold water inlet too. Very hard to get to. I finally was able to remove and replace it and it solved the problem!! We always had noise coming from the hot water heater when running water(hot or cold). This also corrected that problem. For months I had assumed it would be the hot water side check valve. At any rate, it is fixed. Since I had everything apart, I went ahead and installed a Hott Rod. I ran a dedicated circuit to the box with a new breaker. Got finished last night about 1:00 A.M. and everything is working great. Thanks again!!
Gary RV_Wizard
Site Team
Excellent! It's always a great satisfaction when a tough problem is licked.
