INTERGAS HRE 28/24 Combi

[Stan]

Stan,
200 CaCO3 mg/l is about 14degrees on the actual Clark scale but there is always a conversion to CaCO3 mg/l hence the 'above 200'.

Unless you need to pressurise the system you will not need the rear frame - not sure they show it for that model in their blurb, I think they show a stand alone vessel & valves.
The offset flue kit allows for a boiler replacement with a conventional center flue hole, & also avoids the flow & return pipe. You can use a straight out flue but you will struggle with the pipe tails & have to shorten one of them, also part of the joint would be in the wall & you would need to do some artistic finishing with plaster to keep it in view. The offset removes all that drama.
Regards

Arthur.

All received Arthur. Many thanks for putting both points into context for me. You've cleared up the offset flue conundrum nicely.