City water not working

[Flyinhy]

I'm sure this question has been asked more than once. My city water hook up has not worked properly since I bought my MH. When I hook it up you can hear water go into the tank for a minute then it starts flowing out of the overflow tube. I'm pretty sure there is a check valve somewhere but can someone give me a starting point on where to look? It's an 2001 sig executive. 

My water pump works fine, I just never really used the city water because I've had so many leaks , I wanted to get all of those stopped first. 

[BradHend]

Sounds like you are leaving your freshwater tank valve open and overflowing it.  There’s a valve to stop filling it and that will stop your problem.  
Should all be in your wet bay or there about. 

Edited April 24, 2022 by BradHend

[Ivan K]

If there is any similarity with ours, we don't have a check valve other than in the pump. Only a simple manual valve straight above the city water inlet that switches between tank fill and inside house plumbing.

[DrDon4u]

I had the same problem. Picture #1 is the check valve that came on the coach when I got it. The hose and fitting that is on the bottom of it is the hose from the city water hose reel. There is an ARROW on the check valve that does not show in this picture. That arrow was the only reason that I knew it was a check valve. I replaced the plastic check valve with a brass one. Picture #2. I had to add a 1/2 in spacer to the bottom of the brass valve so that the coupling would push up on the check valve. The only place I could find both check valves was a RV parts stores. The Big Box stores didn't have them. Good Luck!!!

 

[vito.a]

Download an electronic copy of your owners manual:

https://www.monacocoach.com/rv-owners-manuals

With an electronic copy you can perform quick searches. 

Section 4 page 112 covers your city/fresh water hookup and city water valve. 

• Connect the hose to city/fresh water hook-up located in service center on the roadside of motorhome.

• The city water valve must remain in closed position.

• Turn on the water supply.

• The water pump can either be in OFF position or in ON position. It will not affect the water pump to leave it on.

• City/fresh water connection has a built in pressure regulator and one way check valve that protects motorhome to 45 lbs 

If this doesn't work, remove the one-way valve and pressure regulator and clean or replace them.  

[Ivan K]

19 minutes ago, vito.a said:

Download an electronic copy of your owners manual:

https://www.monacocoach.com/rv-owners-manuals

With an electronic copy you can perform quick searches. 

Section 4 page 112 covers your city/fresh water hookup and city water valve. 

• Connect the hose to city/fresh water hook-up located in service center on the roadside of motorhome.

• The city water valve must remain in closed position.

• Turn on the water supply.

• The water pump can either be in OFF position or in ON position. It will not affect the water pump to leave it on.

• City/fresh water connection has a built in pressure regulator and one way check valve that protects motorhome to 45 lbs 

If this doesn't work, remove the one-way valve and pressure regulator and clean or replace them.  

This is exactly what's in my manual so there should/could be similarity to yours. Assuming so, the only way city water gets into the tank from the top fill, is when the twist valve is open or not sealing. If it is filling from the bottom of the tank, it is through the water pump. You could tell by the sound of it. There's no other way for the tank to fill up. I removed the original restrictor/check valve at the city inlet and replaced it with a nicer regulator with valve. Very simple system.