Coach water pump problem: hot and cold

[Oh-one]

We were in northwest GA for a week or so and the temp. got down below freezing. We were using the on board water and pump. The morning shower proved to be a real adventure. The pump would first cycle on and pump cold water to the shower and then suddenly pump all hot water. It never mixed the two. The pump was cycling on and off despite the fact that the shower valve was continually open. I opened the cold water valve on the bathroom sink and the pump then remained on continously and the water temp. mixed properly in the shower. What the heck happened? I fixed the problem but I have no idea why it happened or what corrected the problem. Since then the pump is working correctly and the shower is OK..???

[Oh-one]

We were in northwest GA for a week or so and the temp. got down below freezing. We were using the on board water and pump. The morning shower proved to be a real adventure. The pump would first cycle on and pump cold water to the shower and then suddenly pump all hot water. It never mixed the two. The pump was cycling on and off despite the fact that the shower valve was continually open. I opened the cold water valve on the bathroom sink and the pump then remained on continously and the water temp. mixed properly in the shower. What the heck happened? I fixed the problem but I have no idea why it happened or what corrected the problem. Since then the pump is working correctly and the shower is OK..???

[Florida Guy]

Sounds like a stuck check valve that is no longer stuck (Frozen?)

[Pusherman]

Oh-one,

What type of coach do you have?

I have a similar problem with my new coach. Only used it once but had the same experience with the shower.

I was thinking the problem was with the anti-scald valve in the shower mixer valve.

Anyone else have any ideas?

[Oh-one]

We have a 2003 Horizon. Is your pump cycling on and off even though the shower valve is open. Your unit should have the newer Moen anti scald valve in the shower. We had our original shower valve replaced by Winnebago because the original elcheepo valve was sooo sensitive that it could not be safely used.

[Pusherman]

Yes, we have the Moen anti-scald valve in the shower. Yes, the pump cycles on and off with the shower valve open.

Wonder if this valve is the culprit.....

[Oh-one]

Try opening the sink cold water valve ,just slightly, in the bathroom and see if the pump runs continously when the shower valve is open.I did this and the shower was mixed correctly.

[Pusherman]

Can't do for a couple weeks -- still winterized.

Anyone else have this problem??

[smlranger]

Pusherman:

Mine was doing that when I first got the rig. The original owner had replaced the OEM shower diverter valve with a Moen. Nevertheless, when we used the shower, the pump seemed to cycle more, pressure was poor, and the water temp was not consistent. When using the bathroom sink, all was well.

What I discovered was the knob on the shower valve was installed incorrectly, preventing full sweep of the valve. Once I fixed that, all was well. Might not be your issue but simple to check.