Baxi Solo HE self shutting down a week after new flow switch installed

[Rogeranerley]

Just had a new flow switch fitted by my regular regulated engineer. Working fine for a few days but is now shutting down after a few minutes of ignition.
There's a swooshing sound coming from the pipe runs when working. I've attempted several bleeds across my 19 rads which seemed to fix the swooshing, how ever that's now returned.
My question is...could sufficient air in the system be causing flow switch confusion and shut down. The refill following the the new switch fitting was a bit of a rushed job in order to check the new switch function.

Thanks

 

[DP]

Call your engineer and let him diagnose the issue

 

[Rogeranerley]

Already in train...just thought I'd ask other experts who might have a view/experience of this situation.