A diverter valve costs about £85 - a switch ? Why a switch? A switch shall we say £15 - Total cost of material about £100
This assumes that these things were actually changed.
Then perhaps a call-out charge of £50 and that leaves £140 for labour - at £35 per our - 4 hours work. Or two hours at £70 per hour perhaps.
So - if the items changed were actually changed then you have been overcharged - but not grossly overcharged.
When your boiler failed it will have broken because of one component failure - it would be most unusual for two items - the diverter and a switch - to have both failed at the same time.
Your current F1 failure code is very probably a completely different fault - you do not say if the boiler engineer actually fixed the original fault or not - I assume he did.
F1 means that the boiler is not firing up - there are several things that can cause this but very unlikely to be the diverter valve.
My best advice is to find another boiler engineer - an independent one - perhaps one a neighbour can recommend to you. The first one is a bit on the expensive side - drop them.
Good Luck...
August 2015
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