No hot water to kitchen tap

[sherrardk]

I was just running the hot water in the kitchen and it was fine, then the pipes began to bang like mad and the hot water turned to a dribble and stopped. I have checked and there is hot water to the bathroom. Any ideas? Thanks

[Old_Geezer]

Sounds like an air lock to me. Although the experts will probably have other options. If it doesn't move soon then the way I cleared my last couple was to connect the 'mains pressure' cold tap to the hot tap, and turn both on. The cold forced it's way back up the hot pipe moving the air. Once the hot overflow had been running a while I turned the taps off, disconnected the hosepipe, and all was well. May be worth a try.

[AlBags]

Standard boiler .. and not combi
HW cylinder heated by boiler
The flow can only really be stopped by the kitchen tap valve/seat.
What sort of tap is it?

[sherrardk]

Hi - its a brand new combi boiler and it is a mixer tap.

[The Builder]

You could swap the tap tails over, sherrard. If it does it on the cold after that, then it's probably the tap valve....... somehow.

[AlBags]

OK.
Recheck flow on upstairs hot supply .. if ok.
Re-check kitchen to see if you get anything.
If not .. it has to be fault in a gatevalve to kitchen .. or tap isolator. It's possible the slow flow is interrupting the flow switch in boiler.
Also check the boiler system pressure is at at least ,75bar on the charging gauge. It may drop if rads need bleeding (air coming out of system)

[sherrardk]

Right, I have bled the radiators but the pressure bar thing on the boiler is not moving off minimum - any more ideas please? Know its something to do with putting more water - or should I just wait for himself to get home? Thanks

[AlBags]

There is a flexible fill loop connected between mains and the boiler system. There is an isolator at each end or one end .. may be washing machine type taps or screwdriver slot. Open slowly to recharge system to 1bar -ish cold system (or about 1,2bar -ish warm system) Turn off and complete bleeding if necessary.

[AlBags]

Keep your eye on gauge .. pressure comes up quite quickly.
Over-pressure operates safety water release valve at 3bar .. so it's still safe!

[sherrardk]

The pressure is ok now (the boiler was having a nap!), can't be arsed with the banging pipe (as I'm not feeling well), so I will leave it for now and the happy pixies pay a visit. Thanks for your help though.

[sherrardk]

Just tried the kitchen tap to see if the happy pixies had been and it worked fine BUT only while the shower was running upstairs. As soon as the shower was switched off, the water stopped and the banging noise started again. Any further ideas or should I get the engineer out who fitted the boiler (surely it should be included in his service as the boiler has only been in since October)? Than