Help ....New heating system noise

[Simon wardle]

Recently my heating system has started a dull consistent thudding/ knocking noise, sounds and feels like it’s coming from unvented cylinder cupboard, possibly water combination valve - I can feel vibration when holding the valve.
Happens regularly throughout day and night but At night this dull thudding is very annoying. It only does this when taps are off and no water running.

I have tried bleeding the rads and draining the whole system.

Any advice please?

 

[dilalio]

Is your UV a Megaflo?

If so, try a recharge of the air bubble.
If not, you'll need a G3 engineer to recharge the expansion vessel.

Also check the tundish/discharge pipe from the inlet control group to see if its letting by on the PRV... This all depends on how its been installed. Photos would help.

But, you might need a G3.

 

[Simon wardle]

Thanks.

It’s a Santon premier plus, tundish is dry. I’ve attached a photo.

I have tried draining the system then refilling? How else would I recharge the air bubble?

 

[dilalio]

You have an EV (shown top left of your photo) this needs checking for airside charge and regenerating or replacing (as required) but this needs doing by a G3 engineer. Guides can be found on-line though.

 

[Simon wardle]

Thanks again.

If I push the shrader valve in the EV I get a jet of air and some water spray, would this signal it’s collapsed?

 

[dilalio]

Might be condensation but yes, it could be depleted or it could have failed.