Filled fresh water tank in course of two days on city water & pump runs

gpshemi

Well-known member
We recently picked up our 3612 and took our maiden voyage.
While on that trip we were hooked to city water and after two or three days I noticed water coming out the bottom of the coach. I traced it back to coming out the vent. When I removed the cap it came out the cap as well. I checked the monitor and the tank was full. So it filled itself over a couple days. I assume that's a bad check valve somewhere. I read it might be in the pump. Yes? No?

Also, this weekend we went camping without hookups. I filled the tank, had issues with the vent line only letting me get 1/3 in the tank, and then once parked the pump ran for a couple seconds every 15 minutes. I figured it was a leak, so I opened up the basement. It's dry. Everything in the coach seems dry as well. No water coming out underneath either. So is this also the check valve?

The camper is a hundred miles away now (leave it there for summer) and I hate to bring it back for a bad pump if that's the case. I'd rather swap it out myself. Is that a possibility?
 

Ray LeTourneau

Senior Member - Past Moderator
Yes, the pump has a check valve built into the pumping mechanism. The rubber may be dried out from non use or there may be debris in the rubber valving. There should be a ball valve in line between the suction side of the pump and the f/w tank. It should be about 12 inches from the pump. You can close this valve to solve the problem temporarily. The pump are easy to replace. 2 hose compression connections and a couple wires. It should still pump fine if you need to use it for traveling or boondocking but you'll have to open or close that valve when going to and or from city water. I keep mine closed most of the time.
 

gpshemi

Well-known member
There isn't any ball valve. Both sides run 3-4' to the docking station. The only thing you can do is unscrew it, remove the four screws, and snip the two wires. That much I know for sure. Question is, will the dealer warranty it that way or not, AND is that the problem for both issues?
 

porthole

Retired
One potential leak that is not very visible is the shower connection.
Pull the inspection plate in the shower and check the connectors.
 

Ray LeTourneau

Senior Member - Past Moderator
There isn't any ball valve. Both sides run 3-4' to the docking station. The only thing you can do is unscrew it, remove the four screws, and snip the two wires. That much I know for sure. Question is, will the dealer warranty it that way or not, AND is that the problem for both issues?
Yes. The bad check valve will allow the pressurized side of the system to "drain" back into the tank. The pressure loss then results in the pump turning back on for a few seconds to build pressure again. Kind of a catch22. Sorry for the mis-information. I assumed all of our pumps had a shut off between the pump and tank. I would call dometic and calmly explain your problem they may send you a replacement pump and have you return the bad one, prepaid. Since your rig is a 2010, maybe your dealer will allow you to just bring in the pump for him to test and replace.
 
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