Airlock in pumped shower system

[Bucks_lad]

Hi there,

I have a pumped water system (not the heating system) that runs a downstairs shower and the upstairs bath/shower and sink. It has all been working fine for the last few years ever since it was installed but it has just failed to pump the hot water, the cold is fine. Could there be an airlock in the pump, and if so how can I get rid of it?

Note: After I turn off the hot taps the pump continues to go until the pressure builds up then it shuts off but as soon as you turn the hot taps back on the pump works but after a short 'spurt' of water it stops even though the pump is going?

 

[Trev B]

Try blocking off the open vent to the domestic tank temporarily, ( tape it up tightly with a plastic bag or similar), and test it then , if it runs ok then it's air getting in from there because it can't draw the water fast enough from the cylinder.

Can't say what it could be because would need to see the system you have and how the pump was piped but at least it should narrow it down a bit and remember to uncover the open vent when you have finished, it is there for a reason.....

Hope this helps,

Regards, Trev.......

 

[Bucks_lad]

I will give it a try. Would it suddenly draw air from there after working fine for all this time though?

 

[PIPERPETE]

The pump impellers are only designed to work to a maximum temp of 60Deg, Hot water ruins the impellers and the bushing between the hot and cold chambers, what happens is that because there aould be a greater force of cold water in teh chambers it forces its way into the hot.