'Ello my luverlies... Combi Boiler has been doing odd things of late and I suspect the diverter valve, here's the bits and bobs...
Boiler = MAN Heitztechnicsomethingorother AKA "Eco-Hometech" about 4 years old now. DHW set to 65 degrees (more later) CH is heating water for UFH at around 55 to 70 degrees (outside temp dependant) So, we run hot tap, Boiler kicks into full 100% power mode but heat goes to CH circuit whacking it up to 80 degrees which then takes a minute or so for UFH manifold thermstat to reduce flow to manifold and UFH.
DHW output from boiler still cold. At this point I generally find shutting taps/shower whatever on and off a few times kicks things back to life, but I am thinking this is only the overlap of excess heat in the CH circuit conductively heating the water passing through the the DHW circuit as it still takes a long while to get above "warm"
Occasionally it's fine i.e. coming out at hotter than bareable (not hot enough for scalding) temp, but most of the time it's just warm enough for a shower.
So.... if it is the diverter valve is replacement a simple job? Inside the boiler case there's an abundance of space, nothing really in the way of anything else. Can I just isolate the boiler pipes (there's a tap on each pipe) then re-connect without draining down system etc? (I fitted an auto bleed valve to top of boiler originally)
Having fitted the water softener about a month ago I thought it might reduce the symptoms if scale was an issue, but although the shower windows have de-scaled themselves the boiler is still playing tricks.
Any ideas before I order up the wrong bit or put in a service call for a component I could replace myself?
Cheers Pete