Gloworm 30cxi Boiler Short Cycling

southcoastrgi

Connection fault between main & display pcb's
Stop turning the power off to the boiler you will blow the pcb again GW don't like the power being turned off

sk240

Have all of the radiators been ballanced correctly, so that they are sending cold water back to the boiler?
If the circuit is fully open, and the flow and return is at the same temperature, then the boiler is short cycling because the water is already hot.
Ideally you need a 15 degree difference between flow and return.
If its still no good, then it might be that the boiler is just over sized for your application (how many radiators and of what size is it feeding?)

richardc1983

When it short cycles the flow is cool barely warm. It cycles within 2 mins of the boiler firing up from all rads being off all day.

Rubidium

richardc1983 wrote: »

The pump is working fine and sounds fine as well. You can hear there is plenty of flow.

You say that "You can hear there is plenty of flow" but the pump impeller my be cavitating and not effectively circulating the water though the system causing cycling. A blockage or partial blockage could cause the same effect.

The 30 cxi requires a minimum flow rate of 1032 L/hr.

Your cycling symptoms are caused by insufficient flow or the flow return differential being too great.

The control circuitry monitors the flow/return temperature differential and if the pump is effectively circulating the water, then the flow and return thermistors/wiring/connectors may be faulty - easily checked by a competent person.

richardc1983

I have the engineers coming out today so they can check.

When I say you can hear the flow you can hear the flow through the rads.