VSD pump with accumulator tank?

The friendliest place on the web for anyone who enjoys boating.
If you have answers, please help by responding to the unanswered posts.


Oct 5, 2007
Vessel Name
Anastasia III
Vessel Make
Krogen 42
I'm putting in a VSD (variable speed) FW pump to replace my old diapharagm type. I know it doesn't need an accumulator tank, but would it hurt to leave one in the circuit? I'm worried about expansion in the hot water tank. If I take the accumulator tank out and put in a check valve, the hot water will dribble out the pressure relief valve on the HW heater.
I changed from diaphragm type to impeller type years ago, without taking out the accumulator tank. when the accumulator failed I got a new one, as the pump cycles so much less with it. Now any overnight water usage (less than an accumulator full) willl not wake other sleepers.
The accumulator will be useful with the new pump.

The HW heater will stop dribeling with a place for the pressure to go.

The FW pump will also stop "softer" , which will extend its life.

AS an Offshore thinking guy (even tho we don't get there often enough ) I prefer to Hard Mount the FW pump, so I hear it run , esp at night .

Blowing the FW tank doesn't matter much on inshore cruises , but old habits die hard.

Top Bottom