Bubbles/sloshing in hot ware cylinder

[johnhump]

When using just the gas boiler to generate hot water in cylinder lots of bubbles/sloshing can be heard. Seems to cycle i.e. sloshing for 10 secs then no noise. Central heating does not generate any noise on its own.

Any ideas - perhaps debris biuld up in cylinder?

Pump is a Grundfos 10/60 and gas boiler is a Glowworm spacesaver.

 

[ChrisR]

Check for a manual air vent near the cylinder , where the boiler connections go in.

 

[johnhump]

Sorry, should have mentioned that I have repeatedly vented the air out of the pipe work next to cylinder on many occations but still seems to be generating air and still sounding like there is sloshing/bubbles going through cylinder and also can be heard back to gas boiler as well.

 

[phhut]

When I moved into my house in 1988 I had this same problem. Called in a plumber I had used in previous house and he fitted an air dissipation device toward the top of the pipe run (next to my hot tank). This cured the problem and I didn't have to bleed every couple of weeks.

Basically from memory as I am not at home - it is a metal box (a bit like the brake fluid box on a car) with 4 connections. The outlet is fed up into the tank overflow to rid the air.

However, a couple of years ago I had the boiler replaced by British Gas and the pump at the same time (since they said I should). Ever since then, the original problem is back.

I did call them back a couple of times but hey just turned the pump down and told me the device had been fitted the wrong way round. All i can say is that whichever way round it should be, it did work and now it doesn't.

 

[ChrisR]

The stuff causing the problem is a gas - either air or a corrosion product, hydrogen.

You can test for hydrogen - do a search on this forum. You can add corrosion inhibitor (anyway - does no harm).

You may have a leak, which lets air in but not water out. Surprisingly common. There are things you can do if that's the case, but try the corrosion route first.