Hi all,
After failure of the fresh water pressure system on my boat in the past, I
have installed additional Whale footpumps, one in the galley and one at the
aft head basin. I have done the plumbing with special non-toxic drinkwater
hose. The hose is connected (with a T-piece) directly after the Y-valve for
the water tank selection.
The foot pump in the aft head is connected with a T-piece to the hose that
runs to the galley foot pump. In between both foot pumps and the taps I have
installed domestic inline carbon water filters in standard transparent
housing (for ease of inspection). All works well. We rarely use the pressure
system now (only for hot water).
However, we have one annoying problem:
After the pump in the head has not been used for 2 or 3 days, the water has
a unpleasant smell for the first 20 or so pump strokes. I have replaced the
carbon filter cartridge to no avail. The water in the galley is perfect, no
smell, no taste, from the first pump stroke. The carbon filter does not seem
to make a difference. I have removed the carbon cartridge in the head
altogether, still smelly water. The situation is exactly the same in galley
and head, same type of hose, same hose-lengths, pumps, filters and taps.
Hoses and filter cartridges do not receive direct sunlight.
Has anyone any suggestions what may be causing the smell?

Regards,
Wout