Hot water goes to header tank when powerflushing forward flow,help!

[diy_massacre]

Hi

I have a gravity-fed system I have flushed it out a couple of times and it has had x400 in the system for the last 4 weeks.

There was one radiator with stubborn flow left which doesn't heat up enough, it has 8mm pipes which I think is the problem, rather than the rad as I have had the rad off and it has good flow with a hose pipe.

I put a Fernox Powerflush pump on with forward flow today but I am just getting hot water in the heater tank and it goes to the header tank overflow. Reverse flow is ok.

What should I do to remedy and flush out the system?

I could put a valve on the expansion overflow to somehow limit the flow but a still allow expansion overbiously thats not strictly legit blocking an expansion......

I wante to increase the concentration of x400 to a higher convcentration and have the one stubborn rad being circulated to try and remove the pipe sludge.

 

[Ric2013]

Read the pump instructions again. You should block/cap the pipes to the F&E when powerflushing (the expansion tank becomes the pump vessel itself).

 

[diy_massacre]

Rechecked, yes it does, many thanks Ric!!