City water filling fresh tank

Nope, it's a sure sign you've lead an impure life.
Probably too late to repent.
(Dont ask me how I know) :B

The pump burping means you are losing pressure in your water lines somewhere. Either a leak or the check valve in the pump. I'm betting it's the check valve and that is why your fresh water tank is filling when using city water.

Memphisdoug wrote:
Why do you have your pump on if you are using city water?

I don't. The meant pump burps when I use it alone.

2oldman wrote:
The pump does intermittently 'burp', indicating a tiny leak.. somewhere.

DutchmenSport wrote:
or , that check valve is bad. Unhooking the old pump, somehow, you disturbed the check valve. .

What check valve?

Why do you have your pump on if you are using city water?

2oldman wrote:
The pump does intermittently 'burp', indicating a tiny leak.. somewhere.

DutchmenSport wrote:
or , that check valve is bad. Unhooking the old pump, somehow, you disturbed the check valve. .

What check valve?

Some campers put a check valve on the Out going pipe from the water pump and before the connection to the incoming city water line, which also has a check valve to keep the water pump from spilling out the city fill.

Other campers depend upon the water pump to keep from back-feeding into the fresh water tank. Check the connection, right at the pump (out going side), see if there is a check valve there, or maybe at the connection point where city and pump (incoming) lines come together.... sometimes, in older campers, there was a check valve there.

2oldman wrote:
The pump does intermittently 'burp', indicating a tiny leak.. somewhere.

DutchmenSport wrote:
or , that check valve is bad. Unhooking the old pump, somehow, you disturbed the check valve. .

What check valve?

Check Valve is a diaphragm inside pump.....not an external one.

That tiny 'burruup' is due to backflow thru pump check valve allowing system pressure to decrease enough to trigger pump pressure switch.

Using pump/more flow thru it may clean up check valve and stop the leaking

The pump does intermittently 'burp', indicating a tiny leak.. somewhere.

DutchmenSport wrote:
or , that check valve is bad. Unhooking the old pump, somehow, you disturbed the check valve. .

What check valve?

Could be the water pump is defective and allowing water to back flow into the fresh tank?

If you are using the camper, the other option (for a quick fix to a difficult situation), is to simply fill your fresh tank and pump from there until you figure it out.

My guess, either the new pump is defective, and / or , that check valve is bad. Unhooking the old pump, somehow, you disturbed the check valve. Take it apart and clean it out. See if that helps before tearing into the pump itself.

Might be a brand new pump, but I agree the check valve inside it is leaking. You can pull the diaphragm apart, and clean it. Could be some debris holding them open.

This is a brand-new pump, and I have no water panel valve.

The only leaking I've found so far is coming from the water fill hole and the air outlet, running down the outside. I sure hope that's all, and my water tank doesn't fall out from internal leak damage.

I'll drain the tank down to 1/3 and recheck things. And for sure turn off the city water.