Hot water problems Baxi duo -tec

[stings27]

Hi all.
Got a call from my brother in law this morning regarding a problem with his Duo-tec.
When he opens the HW tap on his sink unit , the boiler will not fire but he reckons ( I have not visited due to the current situation) when he opens the taps upstairs in bathroom it does ???
Says there’s plenty of pressure throughout the house.
Any ideas folks ?
Thanks.

 

[SimonG]

Wheres the boiler? Could be a dodgy check valve or faulty mixer/shower.

 

[stings27]

Hi Simon. His boiler is in the utility next to the kitchen.

 

[Gasmk1]

if it is a combi then the flow through the hot tap upstairs is enough to lift the diverter valve the tap downstairs possibly not, so could be tap on sink as said but I would bet diaphragms on diverter valves are on way out

 

[stings27]

Thank you. He says there’s plenty of pressure throughout tho that’s what I don’t understand. I did ask if he had a filter on the nozzle of the tap that maybe was limed up.

 

[Ben-gee]

You got it, there will probably be rubbish blocking up the flow straightener on the kitchen tap - usually met with “ oh , I could have done that myself”