Under Pressure!! or not?

[Rohan]

Ok this is i presume a pressure problem, just wanted to get some opinions please. valliant combi boiler doesn't fire up hot water for the kitchen taps (closest to boiler if that makes a difference) BUT is fine for the bath tap and if you run the bath hot water tap at the same time as the one in the kitchen then hot water also comes out in the kitchen

Could it be that the pressure is too high from the mains? so the kitchen tap on its own doesn't lower it enough to get the boiler to fire up? the bathroom tap has a large outlet. Can i sort this out by tweaking the water mains valve tap? or could it be more sinister

No problems with central heating. Sorry i don't have more details on the boiler at the moment if needed i can get these. Also could i really mess things up if i go 'tweaking' the mains tap?

 

[Bahco]

Sounds like your kitchen tap is not opening enough to alert the boiler to fire, i.e insufficient flow.
Service your tap or replace

 

[kevplumb]

what is the mains pressure ?
what is the flowrate ?

 

[croydoncorgi]

It's unlikely that adjusting the flow limiter under the boiler will make any improvement. If the boiler only fires with a large volume of water going through it, reducing the flow will probably make it worse. If the boiler is an older-style Turbomax, you probably need a replacement diverter valve assy (which usually works out cheaper than trying to fix the old one).

 

[Rohan]

Thanks for your replies, not as simple as i thought so i will call a plumber and change the kitchen tap as i dont like it anyway! I have tried adjusting the boiler flow limiter and it made no difference. The boiler is only 4-5 years old. Its odd that this problem should suddenly occur after 5 years with no problems in this department isnt it?