Powerflush not circulating

[ROSSGR]

Hooked upto a system the other day and it wouldn't circulate???

Sealed system,Yplan, system chb. GLoworm Ultimate 22mm pipe to pump/valve before it goes undergrground into 15mm.

The problem is poor circulation initially. The boiler cycles off before there is any heat to the rads. Heat gets about 8mtrs fro chb when this happens, which is before the pump and motorised valve
.
Had new pump/valves/valve/motor/sensors


After 1 hour all the radiators are roasting, but the boiler shouldn't cut off before there is heat at the rads. I think the return is choked but can't get nder the floor.

Any way of finding out? Was thinking of running a return pipe from furthest rad above the ground into the 22mm return near the chb, this should confirm that the chb HX and flow pipes are ok yeah?

Cheers for any advice

 

[nogoodatfaultfinding]

This would seem to be the old Cold Fill, Vent, Flow blockage.

Have you tried a magnet on this section yet ?
if not do that first.

 

[ROSSGR]

Was changed to a sealed sytem 3years ago so think this is ruled out......

 

[nogoodatfaultfinding]

Was changed to a sealed sytem 3years ago so think this is ruled out......

Sorry mate never read that part



Has the coil gone caput in the cylinder?

 

[nogoodatfaultfinding]

Was changed to a sealed sytem 3years ago so think this is ruled out......

Drain system and isolate cylinder, If you can fill and get water through all pipes this way with a hose then its the cylinder.

 

[ROSSGR]

No, problem more on CH.

Sometimes o/heat pops when heating on only.

It is certainly a return issue, when some of the rads are trying to heat the flow is roasting, return freezing.....NO whooshing noise when etc when it does start to heat...

 

[nogoodatfaultfinding]

No, problem more on CH.

Sometimes o/heat pops when heating on only.

It is certainly a return issue, when some of the rads are trying to heat the flow is roasting, return freezing.....NO whooshing noise when etc when it does start to heat...

Sounds to me like a cylinder issue.

 

[ROSSGR]

Surely when on CH only, flow to cylnder shut.
Circulation around rads crap though.....