Expansion Vessel Charge

mark23

How often does an expansion vessel need to be recharged? Could a low charge cause very infrequent (every 30 minutes) of a water pump on the same loop?

delboythedub

If your water pump comes on of ifs own accord every 30 minutes check for a dripping tap And your toilet bowl. Think if you google Stuart Turner pump fitting instructions it tells how to check expansion vessel.

mark23

Its only on the hot water loop (if I isolate the hot water taps the pump doesn't cycle) so it can't be the cold water taps or toilets. I checked the hot water taps and can't find a leak.

halkar

Not sure what make the pump is but there may be air trap in the pump and you can bleed it if there is bleeding port somewhere on the pump. Also may help if you switch off the pump from mains at night or when not needed to rest it for a while. This works for me when my pump goes crazy. Assuming you have no leaks somewhere. Toilets are usually number one cause of pumps running sporadically.

Wearb

Check that your tundish is dry, though isolating your tap wouldn't stop a faulty vessel problem.

mark23

I already turn it off at night. When I close the valve on the egress side (isolating it) the pump stops cycling so I don't think it's a problem with the pump itself.

mark23

I don't have a tundish that I can tell.

mark23

It turns on very regular (to the minute) but I think it slows or maybe stops when the water heating is on. As a test, I completely drained the hot water so it was cold and it stopped entirely