Water tank fills up when hooked to city water

CAnthony · 03-22-2017, 07:38 PM

Our 2014 Meridian 36 is doing something we don't understand: when we are hooked up to City water and have the water pump off, the water tank will gradually fill up, forcing us to turn on the water pump to use the water in the tank. This doesn't always happen, but it is fairly frequent.
Has anyone else had this experience?

pghbob · 03-22-2017, 07:46 PM

Quote:

Originally Posted by CAnthony

Our 2014 Meridian 36 is doing something we don't understand: when we are hooked up to City water and have the water pump off, the water tank will gradually fill up, forcing us to turn on the water pump to use the water in the tank. This doesn't always happen, but it is fairly frequent.
Has anyone else had this experience?

not sure about your meridian but our fleetwood has a valve for "bypass" or "tank fill" when hooked to city water - have you checked that valve? Perhaps is is in the wrong position or faulty. Just a thought

PJStough · 03-22-2017, 07:50 PM

Quote:

Originally Posted by pghbob

not sure about your meridian but our fleetwood has a valve for "bypass" or "tank fill" when hooked to city water - have you checked that valve? Perhaps is is in the wrong position or faulty. Just a thought

This would be my suggestion as well. Our diverter valve failed a couple of years ago.

Stevegd007 · 03-22-2017, 07:50 PM

Tank fill valve must be in the open position. Check it!

Lault · 03-22-2017, 07:53 PM

Also I have replaced 2 water pumps that fix this issue, hope the latest one last longer.

Saber77 · 03-22-2017, 07:59 PM

As others have said, there is really only one source of this problem and that is the fill/city water valve. Be sure it is in the "city" position firmly -- maybe work the valve back and forth several times to ensure that it seats. If that doesn't fix it, then it's probably a faulty valve.

firedoc · 03-22-2017, 09:14 PM

Quote:

Originally Posted by Saber77

As others have said, there is really only one source of this problem and that is the fill/city water valve. Be sure it is in the "city" position firmly -- maybe work the valve back and forth several times to ensure that it seats. If that doesn't fix it, then it's probably a faulty valve.

Actually there is not just one, see reply 5.

Afubar · 03-22-2017, 09:59 PM

I had a similar problem with my RV, since my Mountain Aire has two different hookups for the onboard tank and the city water I knew that a fill/city valve in the wrong position couldn't be the problem. Turned out to be a faulty check valve in the water pump that was allowing water to seep past it into the tank. Cheap easy fix to replace the valve and not the whole pump.

Old-Biscuit · 03-22-2017, 10:28 PM

Quote:

Originally Posted by Afubar

I had a similar problem with my RV, since my Mountain Aire has two different hookups for the onboard tank and the city water I knew that a fill/city valve in the wrong position couldn't be the problem. Turned out to be a faulty check valve in the water pump that was allowing water to seep past it into the tank. Cheap easy fix to replace the valve and not the whole pump.

Exactly.........

Two methods for water to get into fresh water tank

Via 'FILL' valve....either left cracked open or leaking thru
Handle slipping on valve stem, bad seat/disc. Replace valve

Via pumps internal check valve---diaphragm not closing allowing backflow thru pump to tank
Usually running pump/using up water in tank will clear the check valve and allow it to fully close.
Check valve can be replaced......just check pump mfg. website for part number

NOW.which one is it ??
Remove line from the EASIEST to access....either off the FILL valve or the Suction of PUMP

Water coming out of pump with city water on.....pump check valve
Water coming out of fill valve with city water on....Fill valve

Don't want to disassemble pump...then get a 1/2" barbed in-line check valve and install in pump suction line.

DAN L · 03-23-2017, 05:10 AM

The fill valve should not be operated with any pressure on it as this will cause the seals inside the valve to fail. Then you get water where you don't want it.
I am told that the seals inside the valve can be replaced without removing the valve.
Do a forum search for more info.

D Lindy · 03-23-2017, 05:17 AM

Winnebago has a history of the city/fresh fill valves failing. Also it could be the check valve on the fresh water pump. Removing, and cleaning the check valve is probably the easiest to do first.

rream · 03-23-2017, 07:06 AM

I have the same Motor home, Had the same problem called Winnebago after I
had the valve replaced in the utility bay and it did not fix the problem - here is what they told me to do -

Flip the winterize valve in the bay over the outside propane tank - fixed the problem - a bit of a pain as you have to flip it again so you can use the pump when not connected to water but this fixed has worked for two years

ahicks · 03-23-2017, 07:13 AM

When this happens on a newer coach, I always suspect the water pump has ingested some plastic shavings or other type crud through it's intake side. That generally will become lodged in one of the flapper valves as they are the most restrictive area of the pump. Of course if your pump is equipped with a filter on the intake, the chances of this happening are pretty much eliminated.

In any case, once some forign object is trapped in one of those valves, the pump will not be able to seal off the water tank when on city water.

More-Gas · 03-23-2017, 10:24 AM

I had the same problem twice it was the water inlet valve (where you hook hose to inlet) the darn thing went bad. Pretty easy fix.

D Lindy · 03-23-2017, 03:54 PM

rream; flipping that valve stops the water from reaching the pump, in your case I'd say all you really needed to do was remove the check valve on the pump blow it out and reinstall it to stop the leak, rather then having to keep flipping the winterization valve.

CAnthony · 03-23-2017, 04:26 PM

These are all good suggestions! Here are some more symptoms:
When using the water pump it cycles quite often- even when we are not using water, but there is no apparent water leak. We suspect the pump is also feeding water back into the tank.
Rream, does your water pump cycle on an unusual amount when you use it?

rream · 03-23-2017, 04:48 PM

Quote:

Originally Posted by CAnthony

These are all good suggestions! Here are some more symptoms:
When using the water pump it cycles quite often- even when we are not using water, but there is no apparent water leak. We suspect the pump is also feeding water back into the tank.
Rream, does your water pump cycle on an unusual amount when you use it?

Not really but I usually turn it off after we use the water

Petro · 03-23-2017, 07:50 PM

I had the same problem in my Horizon. The tank fill valve was faulty and needed to be replaced. When not on city water my pump cycled on and off every now and again.

Don

tombones49 · 10-14-2018, 03:22 PM

My 2004 Winnebago 32V had the same problem so I installed a new plastic fill valve from Winnebago. Cheap plastic valve was no better than the old one. I then just went to the hardware store and picked up a brass ball valve, added a couple of 1/2" barbed hose fittings and screw clamps and mounted the valve right where the old valve was. The result was a valve that is strong enough to withstand to 40psi water flow and it looks like a factory mount. Hope this helps.

CAnthony · 10-15-2018, 06:29 AM

We thought it might be a faulty tank valve, but it turned out to be the check valve. Once that was replaced, everything has been fine.