Cold Radiators in Flat Using Open Vented Back Boiler System
Posted: Fri Dec 05, 2014 4:07 pm
Need help with a central heating problem (old, but reliable back boiler, open vented system in a flat - only 4 rads): HW is boiling. The 2 rads nearest boiler/pump are boiling. However, the 2 rads furthest from the boiler/pump rads take ages to warm up and then they only get slightly lukewarm.
I've tried a number of things to resolve it:
1) Turning off the 1st hot rad, made no difference.
2) Turning off both hot rads, made a marginal difference (i.e. 3 & 4 rad get very slightly warmer).
3) Took off one of the cold rads, no sludge at all. Also run off some water from the in valve of the rad, also totally clean.
4) Bled all rads - no trapped air at all.
Not sure if its:
1) An airlock, or some other blockage? The system can be quite noisy with a sort of intermittent slithery/gurgling sound (like a babbling brook ;).
2) Or the old 3 port Manual value (HotWater/CentralHeating) with a 'Simplicity' plastic front (a bit like the Rega Diverta valve). This is seized in what looks like the mid (both) position, can't shift it at all. Maybe it's really favouring the hot water?
Any help/suggestions greatly appreciated.
I've tried a number of things to resolve it:
1) Turning off the 1st hot rad, made no difference.
2) Turning off both hot rads, made a marginal difference (i.e. 3 & 4 rad get very slightly warmer).
3) Took off one of the cold rads, no sludge at all. Also run off some water from the in valve of the rad, also totally clean.
4) Bled all rads - no trapped air at all.
Not sure if its:
1) An airlock, or some other blockage? The system can be quite noisy with a sort of intermittent slithery/gurgling sound (like a babbling brook ;).
2) Or the old 3 port Manual value (HotWater/CentralHeating) with a 'Simplicity' plastic front (a bit like the Rega Diverta valve). This is seized in what looks like the mid (both) position, can't shift it at all. Maybe it's really favouring the hot water?
Any help/suggestions greatly appreciated.