Oh FFS here we go, another ****ing troll, can I sugest GD might be more suited to you! It’s not my logic, it’s my (& ohtres) understanding of the new regs; a loop off a heating system is not an independent heating system. I didn’t change the wording in the 2010 BR’s, all I said was that the wording has changed which as far as I can see precludes teeing into the main wet system; draw from that what you will but my interpretation is that you now require an independent heating system. We are talking about “wet” systems here; electric heating is a stupid example to use for obvious reasons.So, using your logic. An electric heating system does the main house. Another does a conservatory. As they are both fed from the same electric supply cable (energy sources) are they both one "system"? No they are not as independently zoned systems, running off one boiler, are not one system either.
What I write is the case. Read the words. Drag them out as I did. It makes perfect sense in the doc. A CH loop is one heating system while another UFH loop off the same boiler is another system. It may also have a DHW loop which is another system. As long as each loop has it own, independent on-off and temp control they are all independent of each other.
I reiterate, please confirm to me that LABC will accept a tee off a wet system (as they used to) because I don’t really understand the logic of the changed requirements (wording) & would be quiet happy to continue as before; as far as I’m concerned there is nothing wrong with teeing off the mail system as long as it can be independently controlled, isolated &, importantly, drained down.