Help, ideas needed: Our Glow Worm 18hxi has recently been serviced and for the last week or two it has started making a strange noise from time to time. The noise is best described like a washing machine turning over slowly, a sort of low whrrrr....whrrrrr....whrrrr, cycling sound. It make this noise when the heating and hot water are actually OFF, and stops and starts the sequence of noises for about 10 to 15 minutes every one or two hours, all day and night. I tried to read pressure but it comes up on display as 8.8 bar - I doubt true and not very helpful (it should be 0.7 to 1.5 I think). I have searched the internet, nothing definite but it might be:
1. Air in the system; suggested solution = turn heating on and hot water on of on off on off etc, then bleed radiator valves.
2. Dirt in system, especially near something important; suggested solution = have system flushed.
3. PCB failed/failing; suggested solution = phone glow worm and tell them little and take the fixed price repair.
Any thoughts out there? I will have to leave it until next week anyway now.
1. Air in the system; suggested solution = turn heating on and hot water on of on off on off etc, then bleed radiator valves.
2. Dirt in system, especially near something important; suggested solution = have system flushed.
3. PCB failed/failing; suggested solution = phone glow worm and tell them little and take the fixed price repair.
Any thoughts out there? I will have to leave it until next week anyway now.