Temp was 19 last night w/ sleet - Cold water and water pump works great(perfect pressure/Excellent pressure) ... turned faucet to HOT and a slow drip only. Gas and Electric working on the water heater. Thinking maybe a check valve is partially frozen. Placed a 100W light in the basement.Anyone have an idea what may be going on here?

There are sever posts about the check valves going bad, and causing a problem like yours. Dusty

I would start by opening the outside door and pulling the safety valve open just a bit to see if the water will flow from there and if its hot. Be very careful in doing this so you don't get burned.

Maybe switching the water heater to bypass would provide a clue.

powderman426 wrote:I would start by opening the outside door and pulling the safety valve open just a bit to see if the water will flow from there and if its hot. Be very careful in doing this so you don't get burned.Pulled valve at hot water heater - hot water does come outHey Powderman - I grew up in Mt. Vernon - where you at in Ohio?

tenbear wrote:Maybe switching the water heater to bypass would provide a clue.I bypassed water heater - cold water runs through the hot side of the faucets??

Hot Water Question - Help Please | Good Sam Community

tenbear
Explorer
Jan 25, 2014
If it is frozen and you let the hot water run, even if it is very slow, the hot water will soon thaw anything frozen on the hot water side. Of course, you have to take the bypass off. (Turn it back to normal.)
PenMan
Explorer
Jan 25, 2014
There is a check valve on the outlet side (hot water) of the water heater. Since you can bypass the heater and run cold water and since hot water will come out the relief valve, the only thing left is the check valve which must be closed and not able to open under pressure. I doubt it is frozen shut since the water is hot. It will need to be replaced. The check valve is there to keep cold water from entering the hot water heater outlet since most do not have a valve on the outlet like some have shown in earlier posts. Most installations have an inlet valve and a bypass valve but no valve that is manually operated on the outlet (so they must have this check valve). Hope this helps.
marcsbigfoot20b
Explorer
Jan 25, 2014
Mfar1234 wrote:
tenbear wrote:
Mfar1234 wrote:
tenbear wrote:
Maybe switching the water heater to bypass would provide a clue.

I bypassed water heater - cold water runs through the hot side of the faucets??

Since it works as expected with the water heater bypassed, the problem is in the bypassed section, the water heater and the pipes into and out of it.

__________

Let me ask this guys ....my water tank sits beside my sink and (class A)... I'm thinking the cold weather froze something on that wall like on of the responders said. I've left faucets open on the hot side ... as the temp rises today will see if it thaws .... MAKE SENSE??

Maybe a line got pinched in the slide?
Mfar1234
Explorer
Jan 25, 2014
tenbear wrote:
Mfar1234 wrote:
tenbear wrote:
Maybe switching the water heater to bypass would provide a clue.

I bypassed water heater - cold water runs through the hot side of the faucets??

Since it works as expected with the water heater bypassed, the problem is in the bypassed section, the water heater and the pipes into and out of it.

__________

Let me ask this guys ....my water tank sits beside my sink and IS on the large slide out section (class A)... the water heater is obviously on this same slide. I'm thinking the cold weather froze something on that wall like on of the responders said. I've left faucets open on the hot side ... as the temp rises today will see if it thaws .... MAKE SENSE??
Mfar1234
Explorer
Jan 25, 2014
wa8yxm wrote:
On my coach,, The water tank and pump, water heater and kitchen are on one side of the house and the Toilet is on the other, Though the shower is on the sink side the plumbing for it runs "long path" (over to the toilet back to the 2nd toilet, and from there around the rear to the shower)

I have heat in both ends of my wet bay.. The other night (First polar vortex) ONE line froze.. I suspect in the middle of the compartment where it is all PEX and no coplings or elbows or other fittings (This is important) Just the cold line in my case.. So to flush the toilet I drew HOT water from the bathroom sink into a six cup measure and poured.

Now.. I suspet the cold line lies hard against the side of the bay (The other side is exposed to the weather) and the hot lies next to it about an inch away from the cold "Wall".. On your coach, may be other way around.

However if that IS the problem, continuing to draw water will fix it.

Else. as has been noted above. check valves are a pain in the water flow.

Kinda confused me on this one talking about the toilet --

will be 51 degrees in a couple of hours - will plug in the water hose and use hose pressure and then try - think I'll put everything on hold for now. problem isnt making any since
tenbear
Explorer
Jan 25, 2014
Mfar1234 wrote:
tenbear wrote:
Maybe switching the water heater to bypass would provide a clue.

I bypassed water heater - cold water runs through the hot side of the faucets??

Since it works as expected with the water heater bypassed, the problem is in the bypassed section, the water heater and the pipes into and out of it.
wa8yxm
Explorer III
Jan 25, 2014
On my coach,, The water tank and pump, water heater and kitchen are on one side of the house and the Toilet is on the other, Though the shower is on the sink side the plumbing for it runs "long path" (over to the toilet back to the 2nd toilet, and from there around the rear to the shower)

I have heat in both ends of my wet bay.. The other night (First polar vortex) ONE line froze.. I suspect in the middle of the compartment where it is all PEX and no coplings or elbows or other fittings (This is important) Just the cold line in my case.. So to flush the toilet I drew HOT water from the bathroom sink into a six cup measure and poured.

Now.. I suspet the cold line lies hard against the side of the bay (The other side is exposed to the weather) and the hot lies next to it about an inch away from the cold "Wall".. On your coach, may be other way around.

However if that IS the problem, continuing to draw water will fix it.

Else. as has been noted above. check valves are a pain in the water flow.
RoyB
Explorer II
Jan 25, 2014
About the only thing left to check is the water line or valve from the HOT side of the water tank to the BYPASS switch valves...

If your bypass is like shown here operate the valve on/off that feeds the HOT side of the water tank. The BYPASS valve and the COLD water valve seem to be allowing water to pass OK from your tests you have run...

My setup is just like the diagram with only the ONE WAY VALVES on the city water side and built-in the water pump side. Since you are getting COLD WATER flow these all one-way valves must be working ok in the setup. I'm assuming you are only using water from the fresh water tank where you are - not city water... The water pump being ON is not required when on city water... Water pump is only reuired to pressure up your system when using the FRESH WATER TANK.

About all I can think of to check-out Good luck...

Hang your drop cord light bulb close to the lines feeding the water tank. Must be freeze related since everything worked OK yesterday

Roy Ken
Mfar1234
Explorer
Jan 25, 2014
Mfar1234 wrote:
RoyB wrote:
This is a very simplified diagram of how the RV trailer water system is layed out. Might give a clue where to look.

If you have COLD WATER at at the sink then it must be at the INPUT to the water heater as well. Pehaps the winterizing bypass vales are not fully in the correct position.

This is a typical three value hot water tank bypass setup. Note the oblong values indicate which direction of water is affected. Might want to be sure the valves are completely turned.

HOT water worked great until yesterday eve

Roy Ken
Mfar1234
Explorer
Jan 25, 2014
RoyB wrote:
This is a very simplified diagram of how the RV trailer water system is layed out. Might give a clue where to look.

If you have COLD WATER at at the sink then it must be at the INPUT to the water heater as well. Pehaps the winterizing bypass vales are not fully in the correct position.

This is a typical three value hot water tank bypass setup. Note the oblong values indicate which direction of water is affected. Might want to be sure the valves are completely turned.

HOT water worked great until yesterday eve

Roy Ken