In message , Fentoozler
writes
Does anyone know of a condensing boiler where the feed and return are
located at the bottom? or is there a good reason why they should be
located
at the top? e.g, in the case of pump failure hot water rises?

I wouldn't let your neighbour anywhere near a gas appliance then - I can't
think of a single wall mounted boiler which ISN'T bottom fed


--
geoff

The new Glowworm Flexicom HX range (open vented) have flow/returns off the
top, the SX and CX range (system) are off the bottom.

Never come across one

It doesn't change the fact that the OP's neighbour is a clueless CORGI
and shouldn't be let near anything more dangerous than a wax crayon

--
geoff