Tony,
Many thanks for your reply and apologies it was the secondary HE I changed, I was thinking there mayt have been a partial blockage oin it.
If the issue was gas related I'd not venture that far, from what I see though there should be no reason for the fault to lie in the combustion...
Guys.
I have a Baxi 105E combi boiler. For a month or two I've had issues with my hot water.
I have a good understanding of the boiler and how it works, although no gas engineer I am into air conditioning so know the basics of a heating system.
The boiler preheats the DHW reserve as it...