On 25/09/2019 09:39, Graeme wrote:
In message , FMurtz
writes

Why not ask the builder or owner?

I did :-)Â* Caught a guy yesterday, and I was wrong.Â* Whatever is
underground is nothing to do with soakaways or septic tanks, and is part
of the heating system, but that is as much as I know.Â* All that can be
seen now is what looks like a couple of plastic manhole covers above
ground.

Ground source heat pump then


--
Any fool can believe in principles - and most of them do!