Waterproof sealant for calorifier leak

[colind3782]

It sounds like the pressure thingy (normally next to or attached to the pump is knackered. It should be half full of air with a membrane in the middle to stop the air dissolving in the water. You might be able to pump it up with a bike pump attached to a the fitting for doing that. Pump it up to about 1.5 bar.

If that doesn't do the trick, then you need to change the pressure reservoir.

I have one you could use, but it is a bit on the big size for what I imagine is the size of your boat. It is 600L for a house with the water supply pump from 48m down in the well.

If you mean an accumulator, there isn't one and, given the lack of space under the galley sink where the pump is located, I can see why but thanks for the offer.

 

[Graham376]

From what you say, deck shower and heads are OK and it's just the galley tap where the pump pulses rather than running flat out. Is it the same for hot and cold supply or just one of them? Any chance some detritus has got into the pipework?

 

[Boater Sam]

Mesh screen on galley tap outlet spout?

 

[wingcommander]

Just for reference,as your system doesn't have one ,an accumulator is their to stop the pump from cycling on / off when taps are closed by increasing pressure. What you describe pulsating on/off with tap open is a restricted flow symptom. My first port of call is the flexible pipe connections, especially the hot. Kinks and twists are common.

 

[billskip]

by increasing pressure.

??

 

[colind3782]

Thanks. I was beginning to think there may be a blockage somewhere. It happens on both hot and cold so it must be in the mixer? As usual, access from below is a bitch!

 

[wingcommander]

??

OK technically it will only build up to the pre set preasure cut out on the pump . However the air in the dry half of the accumulator/ expansion vessel will compress . So if any preasure is lost ie dripping taps the accumulator will keep the system pressurised longer to prevent nuisance pump cycle. Its also the reason you get a good blast when first opening the tap then the pump kicks in .

 

[thinwater]

... It should be half full of air with a membrane in the middle to stop the air dissolving in the water. You might be able to pump it up with a bike pump attached to a the fitting for doing that. Pump it up to about 1.5 bar....

It is surprisingly little known that this is a maintenance item. I just pumped up the reservoir on an RO at my house a few weeks ago. The volume per cycle had been falling for years and I was lazy. ~ 20 stroke with a bike pump. Now it is as good as new. It took about 15-20 years to bleed down.

 

[wingcommander]

It is surprisingly little known that this is a maintenance item. I just pumped up the reservoir on an RO at my house a few weeks ago. The volume per cycle had been falling for years and I was lazy. ~ 20 stroke with a bike pump. Now it is as good as new. It took about 15-20 years to bleed down.

Even more surprising when the accumulator gets confused with the expansion vessel.
Simple terms...the accumulator is fitted on the cold side (before the calorifier) .the expansion is fitted on the hot pipework post calorifier.
They are exactly the same components (often causing the confusion) ..accumulator preasure is set lower than the pump operating preasure..expansion is set higher..but lower than thePRV operating preasure.
So on the expansion vessel the diaphragm isn't distorted by the pump preasure, the heated water in the calorifier will continue to increase beyond the pump switch off preasure...this will now distort the expansion diaphragm.