converted from tank fed to combi & issue DHW bath only

[markbebb]

Hi

Just swapped out my traditional tank fed HW system for a 35KW combi capable of 14.5 l per min on 35deg temp rise. Incoming pressure and flow rate are ok - 3bar and 15 l per min.

1st DHW tap from combi is downstairs loo and flow is great. As soon as it goes upstairs the DHW flow to the bath is rubbish. Shower and on suite basin upstairs are good though. Mains water into combi is 15mm and also to 1st DHW tap. Before it hits the bath it switches to 22mm that was from the original tank as It was hard getting to 22mm to replace with 15mm.

Would 15mm to 22mm into bath cause a poor flow rate at bathroom tap?

thanks

 

[Happyplumber]

Ah the joys of combi,mate you have to learn to live with the compromise,you cant have best of both worlds,the taps are full bore probably and the pipe should be 15mm all the way otherwise ur wasting hot water that stored there everytime you turn the tap off

When you are new to combination boiler then you realise all the drawbacks of the old system ,running the bath and not effecting anything in the house ,water coming out of the tap at 55 C and the missus can washup whilst you have shower or run the bath

don't try that with the new all singing and dancing combi and start saving a few quid to for the inevitable breakdowns give it year or so