Leak Between Fresh Tank and Pump While Flushing Water Heater

[GallenH]

My "water supply question" garnered a lot of views but no replies. Somewhat expected since few would know the Pleasure Way specifics. So I'm shifting to a more general question.

If I follow the plumbing, a line comes out of the FW tank and goes to the water pump. It splits after the WP with a line going to the hot water tank and a line going to the cold water faucet and toilet feeds. Hot water comes down its own lines when HW faucets are opened.

My leak occurs in the very first leg: between the FW tank and the WP. So what I'm pondering is why it would leak there when the FW tank is empty, when the system is no longer under WP pressure, and when I'm flushing the HW tank. I have a ShurFlo pump which has a backflow check valve in the head. Why would water come back through the WP and leak out between the empty FW tank and the pump.

So I know that the ShurFlo is supposed to have the backflow valve. Does a FW tank typically have a valve at its outlet to prevent backflow as well?

If you can offer any suggestions they would be, as always, greatly appreciated.

Thx.Glenn

 

[booster]

Unless you have a 3 valve bypass with the valves the cold fill line closed, the cold line is attached to water heater at the low end and any water you put in with go out that connection to the cold line and out the bottom where your leak is.

 

[GallenH]

Unless you have a 3 valve bypass with the valves the cold fill line closed, the cold line is attached to water heater at the low end and any water you put in with go out that connection to the cold line and out the bottom where your leak is.

Thx for reply. But as it goes back through the cold line wouldn't it have to go through the water pump on its way to the leak area? If so does that suggest my backflow check valve in the pump is faulty? I did notice that ShurFlo sells a repair kit for the backflow valve in the WP head.

 

[GroupB]

Thinking of backflow preventers that are used on hose bibs. They are closed when pressurized but open to atmosphere and leak when pressure is relieved.

Seems probable that it has something to do with the backflow device when no-pressure rinse water meets it. Maybe faulty or the path to the ground is blocked.

 

[booster]

The check valves do go bad quite often so that is a possibility IIRC they are just rubber flap valves so inlet stroke pulls them tight and they may stay open the rest of the time. Do you have a fresh tank fill valve so you can fill from shore water? If so, then if that was leaking it would also get back to tank line to the tank as the tank and pressure side of the pump and plumbing would be connected through the leak, at least that is what would appear to happen per the Roadtrek plumbing diagram.

 

[GallenH]

Sorry booster: busy week. I don't think I have a valve; at least I've never seen one. I haven't ever used shore water. The PWay has an inlet for a gravity feed to the FW tank and also a place where you can connect a FW hose in the same compartment. I always assumed that the latter was for shore water and that it somehow bypassed the pump entirely. At least that's what the old owner's manual states. Never investigated it.