Hi all, first post but have a major issue that's causing me headaches. My system boiler (Glow Worm Flexicom 18hx) continues to cycle to keep itself up to temperature, even without any demand from the programmer (Drayton Lifestyle LP 522) which is also causing the pump in the upstairs airing cupboard (Grundfos Selectric 15-50) to run constantly due to the pump overrun unless the boiler is manually switched off.
We have no room thermostat so only control is the programmer.
Also no frost thermostat, and hot water is from a Joule Cyclone 150L storage cylinder in the airing cupboard. Boiler is in downstairs kitchen cupboard.
Only bought the house recently and have had a plumber/heating engineer out to look, he replaced the actuator heads on both two port valves and tested both the actual valves as functioning fine, he then spoke to glow worm who decided it must be the PCB on the boiler, which we have also now replaced which has made no difference. We have also replaced the programmer with a newer model just in case that was causing any demand fault, which has not made any difference either.
Having set the boiler to show operating codes on the screen I can see that it's cycling normally, then once up to temperature goes into the standard set time pump overrun, then before that can finish it fires again as if it's receiving a demand.
It's stressing us out as I know it's costing us on gas + electricity as well as unnecessary wear on the boiler and pump, plus as the airing cupboard is in the main bedroom we can hear the pump running (albeit quietly)
Could anybody think of causes we might not have come across yet?
Can give more info on system or add pictures if I've left out anything important.
We have no room thermostat so only control is the programmer.
Also no frost thermostat, and hot water is from a Joule Cyclone 150L storage cylinder in the airing cupboard. Boiler is in downstairs kitchen cupboard.
Only bought the house recently and have had a plumber/heating engineer out to look, he replaced the actuator heads on both two port valves and tested both the actual valves as functioning fine, he then spoke to glow worm who decided it must be the PCB on the boiler, which we have also now replaced which has made no difference. We have also replaced the programmer with a newer model just in case that was causing any demand fault, which has not made any difference either.
Having set the boiler to show operating codes on the screen I can see that it's cycling normally, then once up to temperature goes into the standard set time pump overrun, then before that can finish it fires again as if it's receiving a demand.
It's stressing us out as I know it's costing us on gas + electricity as well as unnecessary wear on the boiler and pump, plus as the airing cupboard is in the main bedroom we can hear the pump running (albeit quietly)
Could anybody think of causes we might not have come across yet?
Can give more info on system or add pictures if I've left out anything important.
