Traditional open-vented system, Glowworm Flexicom 24HX boiler, new 3 years ago.
Yesterday I changed a downstairs rad and some pipework so rather than drain the entire system I blocked the expansion pipe with an end cap and closed the stopcock on the F&E tank outlet. By draining off a little water from the CH I was able to reduce the flow to just a trickle and make the water "hang" in the pipes, good enough for a quick cut and pop on an isolator to the rad pipework.
This morning there's no hot water.
Pump is making a racket and boiler was displaying F25 and now displaying F22. Opening the bleed screw on the pump produces water and varying the pump speed makes no difference.
I've opened the auto vent on the cylinder circuit and no air came out.
The CH runs separately although the pump is noisy but as soon as I switch on the HW the boiler ramps down and stops.
Any suggestions?
Yesterday I changed a downstairs rad and some pipework so rather than drain the entire system I blocked the expansion pipe with an end cap and closed the stopcock on the F&E tank outlet. By draining off a little water from the CH I was able to reduce the flow to just a trickle and make the water "hang" in the pipes, good enough for a quick cut and pop on an isolator to the rad pipework.
This morning there's no hot water.
Pump is making a racket and boiler was displaying F25 and now displaying F22. Opening the bleed screw on the pump produces water and varying the pump speed makes no difference.
I've opened the auto vent on the cylinder circuit and no air came out.
The CH runs separately although the pump is noisy but as soon as I switch on the HW the boiler ramps down and stops.
Any suggestions?
