Warm Central Heating Header Tank - Urgent(ish)

[TheScullster]

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

[Mary Hinge]

Nowt to worry about.

Remember the 15mm feed is typically referred to as the F&E - feed & expansion. Depending on the layout and size of the system this may cause the F&E tank to become warm, after all the increase in volume of the water as the temperature increases has to go somewhere. If the vent is cold then it can't be overpumping.

Personally if I were you I'd seriously consider going sealed, saves a lot of hassle for a very little cost.

[Ed Sirett]

If the radiators were all fully hot then this would be quite normal. After a while the header tank will cool down and little more vapor will come off it.

It a pity that given that an overhaul was being done that the heating engineer chose not to go to a sealed primary. However the boielr maynot have been suitable, I suppose.

[TheScullster]

"Ed Sirett" wrote

Thanks Ed/Mary

It was my decision not to go sealed at this stage. Having had leaks previously in the buried piping (concrete ground floor), I was reluctant to up the pressure on the primary/heating side. House is 1970s build (possibly the worst phase for quality in building history IMHO). Prior to this period there was still some pride in workmanship, after it, the regulations helped to restore some standards.

One or two neighbours have gone sealed/combi. Some have got away with it but some certainly haven't!!!

Phil