Hi all

Reason for urgency is the plumber is on site today so want to catch him with
any concerns!

My central heating re-furb is just about complete.
One of my prime objectives was to cure pump over in new system (original
system was serious bodge and suffered considerably with this).

Went up in the loft this morning to check that pump over was not occurring
and discovered header tank is quite warm, not just tepid. The contents also
looked quite agitated (a bit like me).
Discussed this with the plumber who claimed that this heat is going back up
the cold water feed.
I checked the 15mm make up water feed from the header tank and it was
certainly hot, at least to the ceiling in the airing cupboard.
The vent pipe was cold, so it does seem that hot water is being pushed back
up into the header tank to some extent.

The pipe layout they have installed is pretty much text book.
The flow comes up to the airing cupboard with nothing taken off it.
It tees across (with the water make up looped in below this horizontal
section within 150mm of the flow pipe, which continues as the vent) and then
elbows down through the pump.

The plumber claims that it is quite usual/acceptable to have a warm header
tank, but I have concerns over condensation etc.
The header tank has a formica board for a lid and this was dripping wet this
morning.

Should I be accepting this situation?
I haven't paid a penny yet, but want to be sure of my ground before
witholding payment.

Does anyone know a source for lids for circular tanks, both heating and
domestic water?

TIA

Phil