Glow Worm 18HXi what is this loud noise when HW starts, not kettling? Video with audio link.

[pennine_lad]

Had following work done to system this week for a poorly performing HW/CH system.

- known furred pipes by rust (a very soft water area, no lime deposits) in airing cupboard replaced
- new seized three way actuator valve
- on previous balance valve settings for all the radiators both HW/CH behaved early morning on usual few hour HW and separate CH timed cycles except lounge rad. cold
- pump in airing cupboard on setting 3 which used for past few years

To try and balance properly, read that first need to determine heating order, so all valves opened and switched on CH.
The video shows it coming on, a very odd to my untrained ear combination of noises and switched off. Tried again in case bubbles? clearing but continues.

Any thoughts what causes this, is it bubbles been cleared despite system being already bled or has something failed.

Thanks.
David

Vimeo video of start up with sound 17 sec

 

[Stuckinarut]

Sounds like it's overheating. Could be blocked heat exchanger, but likely air locked. Check the pump is spinning.

 

[pennine_lad]

Pump is spinning, will it clear itself if left on or does it need a plumber in. Almost sounded like a mechanical failure like a fan? spooling down and scraping on something. Could opening all the valves to check rad. heating order have released some air somewhere? System has been bled at rads.

Don't want to risk any damage leaving on. No error codes immediately coming up as thought most key systems were monitored for safety?

Thx. David

 

[Stuckinarut]

It's better cleared properly rather than relying on an automatic air vent (assuming ones present). Are all valves open and all air expelled from everywhere?

 

[pennine_lad]

It's better cleared properly rather than relying on an automatic air vent (assuming ones present). Are all valves open and all air expelled from everywhere?

Thanks. Not sure if air vent but there's a vent to loft teeing off the pump circuit.

All rads bled and both control valves and gate balance valves open.

To be safe will ask the plumber round after Christmas. Have electric fall back for HW and CH so can live without for a good while.