Powerflushing on backboiler to combi conversion

[adamekc]

When converting fom backboiler to combi when would be the best time to powerflush during the conversion and where is the best point for connecting the equipment takeing into account you don't really want to flush the old boiler, cylinder etc. Also can the powerflusher be used to fill the heating circuit to flush it prior to installing the new boiler if you have isolated and removed all the old stuff that you don't need and just have the heating circuit connected. Kamco say across the flow and return at the boiler prior to installing the new boiler so how do you get the water into the circuit. Grateful for opinions on this.

 

[WHPES]

Do all the pipewok modification and plumb everything in, the powerflush before commissioning. You can fill up the rads and much of the pipework when powerflushing but you are going to get a bit of air in when you turn off the powerflush and remove it. Just bleed everything off and top up.

 

[moony]

we just flush the whole system out before we fit boiler - using the flow and return thats going to the boiler once fitted.

 

[bigcheese]

I would have thought you would have to flush after the boiler had been fitted aswell so as to remove flux etc.

 

[stevetheplumber]

I would have thought you would have to flush after the boiler had been fitted aswell so as to remove flux etc.

if you flush with the boiler in youll get crap into the heatexchanger so do all pipework and flush just before connecting last bits to boiler then cold flush with boiler connected then hot flush then fill and add inhibitor

 

[moony]

big cheese we never flush a boiler mate.

and if doing a boiler change and you then flush the system with the boiler attached therefore flushing dirty water through the boiler we were advised it could invalidate the warrenty (worcestor).