dual system

lens200 · 22 Nov 2007

I live i an old ex council house (airey).
2 rads upstairs and 2 rads downstairs work on the front of the house, the 2 up 2 down at the rear dont, there is a new pump fitted, and the system is heated from a coal power back boiler, also when the heating is off one rad in the front bathroom still gets scolding hot, when the fire is lit. Please help.

Breesey · 22 Nov 2007

What type of valve do have in the system?

Have you tried closing the front rads to see if the back ones heat?

The bathroom rad is probably on the hot water circuit.

JohnD · 22 Nov 2007

turn down the bathroom one. It may be offering an easy path for the flow of water, so stealing flow from other parts. And you say it is scalding hot too.

It is quite common to have a bathroom rad that is hot all or most of the time, this is good for drying towels, but unless you keep it turned low and/or have a TRV it is wasteful of energy.

Whenever you have a system with some hot rads and some cold ones, start by turning down the hot ones. If this cures it, Balance the Radiators (see info at top of this Plumbing Forum)

Nige F · 22 Nov 2007

lens200 said:
I live i an old ex council house -- heated from a coal power back boiler, also when the heating is off one rad in the front bathroom still gets scolding hot, when the fire is lit. .

That one is probably on a gravity loop to act as a heat sink.......you shouldn`t be able to turn it off

well, you wouldn`t if I`d installed it cuz it`d have no valves

the other ones that are hot can be shut as suggested....if it`s a steel panel rad like the others/modern ones....it won`t be on the hot water/secondary circuit......if it`s a heavy cast iron one , it probably is on sec .

I wouldn`t worry about wasting energy from a coal fire ..........the heat`s got to go somewhere

JohnD · 22 Nov 2007

sorry didn't notice it was coal.

bengasman · 22 Nov 2007

Search existing threads on – back boiler – for additional useful info

Nige F · 22 Nov 2007

JohnD said:
sorry didn't notice it was coal.

thought you`d missed that

lens200 · 24 Nov 2007

I turned the front ones of and the rear still dont work, Ive just added some sludge remover after drainig the whole system still nothing, they have been bled and bled till I felt hot water entering then they still dont work. ?.

JohnD · 24 Nov 2007

what colour was the water when you drained?

if you bleed a bit out, what colour is it now?

If it has gone very black, that is the sludge being softened and washed away (which is what you want).

However if there are any area which are completely blocked, the chemical will not be able to circulate there

If you have badly sludged rads, you can take them off and squirt them through with the hosepipe in the garden, but give the chemical a couple of days first.

When you bleed the rads, does water squirt vigorously out of all of them?

Have you got any thermostatic radiator valves? these sometimes jam shut.

How long ago did it last work?

lens200 · 1 Dec 2007

I would just like to say thankyou to all who helped, all rads now working, just turned out to be the thermostatic valves, who would have thought all four would be knackerd, apparently the system has not worked for a couple of years, as I have only lived here for a couple of weeks, thanks again.

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dual system

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