Combi Boiler pipe noise

Alex1983

The internal vessel is usually sized for 100 litres of water, as a rough estimate you can use 10 litres per radiator as your system size.

You list 9 rads above so should be ok but then the last message says 11, which will mean the internal one is slightly undersized.

He should reduce pump speed on a combi, it's needs setting to max speed and I'd have it fixed speed.

wingman83

Alex1983 wrote: »

The internal vessel is usually sized for 100 litres of water, as a rough estimate you can use 10 litres per radiator as your system size.

You list 9 rads above so should be ok but then the last message says 11, which will mean the internal one is slightly undersized.

He should reduce pump speed on a combi, it's needs setting to max speed and I'd have it fixed speed.

Hi Alex

Its 11 rads including two towel radiators (sorry, didnt include it in my earlier list).

He did reduce the pump speed on the boiler.

"it's needs setting to max speed and I'd have it fixed speed" - Sorry, couldn't understand this bit. Should we try put it in max speed and then fixed speed (medium) !?

Alex1983

Sorry should of said the pump speed should not be reduced on a combi.

The setting to put it into max speed and fixed will be access from the pcb installer menu.

wingman83

Alex1983 wrote: »

Sorry should of said the pump speed should not be reduced on a combi.

The setting to put it into max speed and fixed will be access from the pcb installer menu.

Thanks again, Alex.

If I understood this correctly; the pump should be put back to max speed. (i couldnt understand pcb installer menu though). I will ask him to change the speed to max and see if it makes the pressure go up rapidly.