Join Date: Oct 2007
My Motorhome: Swift Kontiki 615
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Does your pump cycle ? That will indicate a leak on the downstream side or a faulty one way valve (our drain valve failed last year causing precisely that).
Ours is 20 psi, whi I THINK is the most common, but do not try putting in a higher rated pump that your system is designed for - that is likely to result in leaks at joints you may struggle to identify or find.
It is also worth checking that there is no obstruction where the pipe leaves the tank, we have a very high hardness level in the water all round this area - it is so bad that it narrows the drain point AND the pipe going to the pump, I do not know where you live or use the MH but that may be worth checking. If we open the tanka d feel the pipe exit it is covered in the deposited calcium salt. Not easy to remove unless you wipe it often with cleaning vinegar and rinse well afterwards (put water in at the same time as keeping the drain valve near the pump open).
Any typo that I make means the errorists win.
Any comments above are only MY OPINION
and should be read as that.