plumbing problem????

[everflow09]

hi all, new to this site and need some advice.
went to a job today and customer has had a problem with a kitchen tap.
the story is....
she only gets hot water and a good pressure at the kitchen mixer tap when the boilers central heating is on. All other taps get hot and a good pressure when cental heating is off. as soon as central heating switches off no pressure at kitchen tap only.she has a combi so understand that is hot water priorty but cant understand why all other taps are ok except the kitchen mixer tap. she has had a new low/high pressure tap fitted and there is check valves and not kinks in any pipe work i can see. british gas went out there yesterday and could not find problem even after servicing boiler and charging her.
has anyone ever come across this or has any advice?
thanks

 

[Puddle]

usually this is due to poor flow through kitchen tap showing up signs of worn diaghram in boiler
What make of boiler is it?
are you saying actual flow rate is less when boiler not on heating mode?
if you open kitchen tap and then another hot out let slightly will boiler fire up and heat kitchen sink?00

 

[everflow09]

hi thanks for getting back to us.
the boiler is an ideal response 80 combi.

 

[fuzzy]

hi all, new to this site and need some advice.
went to a job today and customer has had a problem with a kitchen tap.
the story is....
she only gets hot water and a good pressure at the kitchen mixer tap when the boilers central heating is on. All other taps get hot and a good pressure when cental heating is off. as soon as central heating switches off no pressure at kitchen tap only.she has a combi so understand that is hot water priorty but cant understand why all other taps are ok except the kitchen mixer tap. she has had a new low/high pressure tap fitted and there is check valves and not kinks in any pipe work i can see. british gas went out there yesterday and could not find problem even after servicing boiler and charging her.
has anyone ever come across this or has any advice?
thanks

no idea, does the pipework split anywhere near the kitchen sink?, can you put a basic tap on to check if the same happens. then you will either confirm a problem with tap or eliminate a possible cause?

 

[everflow09]

sink only has 1 taphole🙁
Hot comes straight from boiler and spilts in an equal tee one going to kitchen tap and one going to whb & bath

 

[fuzzy]

sink only has 1 taphole🙁
Hot comes straight from boiler and spilts in an equal tee one going to kitchen tap and one going to whb & bath

i dont see how it can be anything other than the tap?????????? is all the pipework close? is the sink the first tee?

 

[everflow09]

she has just had a new high/low pressure mixer tap fitted. that was the first thing i thought when wnet there. pipework is quite close boiler just next to sink. sink is the first tee.
'puddle' says it could be the diaghram in the dirvertor valve - makes a bit of sence

 

[fuzzy]

she has just had a new high/low pressure mixer tap fitted. that was the first thing i thought when wnet there. pipework is quite close boiler just next to sink. sink is the first tee.
'puddle' says it could be the diaghram in the dirvertor valve - makes a bit of sence

true but you would expect it to be the same with all taps

you never know with this plumbing melarky!😀

 

[everflow09]

i know. thanks for your help tho