Boiler: Ideal WLx RS50 wall mounted with balanced flue
Pump fitted next to hot water cylinder 3-way valve also fitted around cylinder area.
Problem.
Switched over to heating and upstairs got hot but downstairs stayed cold, bleed rads but no joy.
Completely drained the system and flushed, put new pump on and re-filled the system.
Boiler now only fires up for 3-4 mins then cuts out on both HW only and CH only, if I have valve set in mid position neither gets hot just luke warm and when set on HW it takes an age to heat up with the boiler only firing for short spells at a time.
When I drained system 2 of the downstairs rads didn’t drain?????
Since firing the system back up I have noticed that the flow pipe from the boiler is very hot and the return pipe is cold (this maybe reason boiler firing for short spells with thermostat in boiler kicking in as water not circulating), this is also the same on my cylinder the flow and surrounding pipes are hot but the return at the bottom of the cylinder is cold and only gets warm if the boiler is on for hours on HW without any water being drawn off, when water is drawn off or CH is called for the return goes cold.
The expansion pipe going to f&e tank is also hot into the loft and the top up pipe for system from f&e tank is also hot.
I think it might be a bad air lock????? Any help and advice would be gratefully received on how to solve this problem.
