Boiler cuts out

[trincomalee]

I have replaced the badly kinked flexible hose and re-set system but boiler still cuts out after a couple of days.
Anyone know of a valve or switch that might be faulty?
e.g. air flow pressure switch? water diverter valve?
Pressure relief valve?

 

[simond]

Try and imagine if there are any important details you have left out of your post.

 

[nickso]

yes, we dont seem to have your shoe size yet.

 

[kevplumb]

Try and imagine if there are any important details you have left out of your post.

like all of them

 

[kevindgas]

well we do know it has a filling loop!

 

[Boilerman2]

Could be a flexible oil line?

 

[trincomalee]

Hi All,
Thanks for all the input,
Hmm anything else I can say? It a Worcester Bosch Highflow 400 RSF gas boiler. Pressure drops over a day or so to about 1.2bar from 1.5bar and it cuts out but will restart easily on pressing the refire button under the control box. Then keeps cutting out at least once a day.
To try to sort I have released the pressure from the mains water inlet and then the pressure from the expansion vessel, pumped up the vessel pressure to 0.9 bar and then repressurised system pressure from the mains inlet for water to 1.5bar. This works ok for about 3 days then cuts out.
Only other oddity I have noticed is the nipple like metal button on top of the inlet area to the water diverter valve looks bent over at about 30 degrees to vertical when it looks like it should be vertical.
I have just replaced the flexible hose as it was badly kinked - no change in cut outs.
That's about it I think.
A plumber I asked to check it last year did a service and said it should be ok (which it was not).
I can sort and replace items in the water system part but won't touch the gas areas!