The BG engineer SHOULD have klnow about the return filter and checked it early on with those symptoms.
Soemetimes they have been wrongly fitted to the flow side instead. Often the filter element inside has been removed "to stop it blocking up" the installer would say.
But it would have been obvious if he had taken the simple diagnostic step of measuring the flow and return temperatures at the boiler.
But BG people often seem to not bother with simple diagnostic checks expecting to go directly to common faults on each model as listed on their computers!
Tony
Soemetimes they have been wrongly fitted to the flow side instead. Often the filter element inside has been removed "to stop it blocking up" the installer would say.
But it would have been obvious if he had taken the simple diagnostic step of measuring the flow and return temperatures at the boiler.
But BG people often seem to not bother with simple diagnostic checks expecting to go directly to common faults on each model as listed on their computers!
Tony