Thanks for updating us. Im sorry to hear you made that decision, although it does suggest the problem was never fuel related and was within the burner, unless the installer rectified a proper when installing.
Not a fan of combi boilers personally but if I remember correctly there's just the two of you and they are decent boilers.
Again thanks for updating us.
Many thanks, Simon
SJB, you may have a few comments to make re Stored combi boilers output and flow rates, there are numerous queries on here re gas combi flow rates as well.
I am looking at a brochure for a Firebird C35 combi boiler and to quote "D.H.W. Guide Performance in litres/min (120 litre draw-off at 40C deltaT) 20". It has a primary store of 40 litres heated to 78C.
Do you know if this guide performance is typical for oil fired combis? and also how is this number of 120 litres arrived at?
My simple calc shows that if one assumes cold water at 10C, then with a deltaT of 40C the stored cylinder will give a volume of 40*(78-10)/(50-10), 68 litres at 50C (which should give 20 LPM but only for 68/20, 3.4 mins, the burner should kick in at 73C and then the 35kw boiler will give a continuous flowrate of (35*860)/(40*60), 12.54 LPM.
My main query is this 120 litre figure?, the flow rates are simple to understand IMO.