it was going so well...boiler cutout

Hello all, I'll try and be brief

Fortic on 1st floor in bathroom, Boiler in kitchen beneath (Glow Worm space saver)

Moved in to house needed space in bathroom for shower so changed old Fortic to conventional vented cylinder with header tank and put whole lot in loft.

Changed old system which was a bit odd:
thermostatic valve with motorised on off (controlled by old mechanical controls) on primary coil with bypass controlled by gate valves. pumped CH/gravityHW

to:
DRandall contractor pack, ie: wiring centre, 3port, tank stat, room stat, controls.

The HW circuit works absolutely fine, but when I switch to CH the boiler cuts out after 15 mins, leaving the pump circulating pointlessly. When I say cuts out I mean it just stops burning, not complete cutout with no pilot. I don't need to reset it in any way, it just stops burning.

Only unusual thing about set up is that I have no room stat, but I have made the neccessary mod to the wiring centre to allow for this..


whats my next course of action?

thanks...

I have made the neccessary mod to the wiring centre to allow for this..

Click to expand...

Where is that crystal ball again !
As that is the only none standard part of the setup, logical diagnosis would be to revert that and hang a room therm (cheap as chips) on a temp extension lead and see if system functions correctly. It will tell you something....

but is the heating working

room stat:
i'm sure mod to wiring centre is ok, i checked with DRandall tech department and they confirmed my solution

CH doesnt get hot quickly enough before boiler stops. I can feel CH pipe close to 3 port getting warm, but thats as much as i can say in the time before cut out.

CH doesnt get hot quickly enough before boiler stops. I can feel CH pipe close to 3 port getting warm, but thats as much as i can say in the time before cut out.

if it takes 15 mins for the pipe to get hot at the valve the valve aint fully opening

thanks all for help will test again tomorrow

++++++++++++++++++++++++

I think I have found solution. no need for any more help for now.

thanks for all help

ben
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