Noise and no hot water from a Honeywell B system

[djw808]

I'm afraid this problem is self-inflicted We have a Honeywell B system installed around a Potterton boiler 7 years ago.

In removing a radiator to allow decorating, I isolated the radiator, drained it, and removed it. However, found the valves either side were leaking, so stopped the supply to the header tank, switched off the system and drained the central heating.

Despite the system being off, this periodically provoked some terrible banging in the pipe work, and refitting the radiator and refilling the system has made no difference. To make matters worse, we now have no hot water through the taps, and the radiators do not become hot. However, pipes either side of the pump are very hot (and the boiler is firing up). I have bled all the radiators and the pump.

I'd be grateful for any suggestions - Many thanks.

 

[kevplumb]

what's a b system ???

 

[bathjobby]

switched off the system and drained the central heating.

What does that mean ? you just switched off the central heating or the hot water and boiler too ? Banging is probably air in the pipework but would think it only bangs if it is being forced (pumped) rather than rising through gravity. You also say you have no hot water through the hot taps now. Is that really no 'hot water' i.e. flowing water but cold, or is it 'no water' through the hot taps ? Again, 'no water' would point to air block.

 

[djw808]

Honeywell "B" system is as it was described at the time, though I could be mistaken. Looking on the web, it looks more like a Honeywell "S" Sundial system, with room and cylinder thermostats together with 2 motorised valves.

I switched off the heater and hot water at the timer controls. The banging occurs whether these are on or off.

Water is running through the hot taps, but is cold.

 

[kevplumb]

1 did you lock the valves open with the levers when refilling

2 is there an air vent near the hot water cylinder

vertical bit of tube with a screw top

 

[djw808]

1 did you lock the valves open with the levers when refilling

No

2 is there an air vent near the hot water cylinder

I don't think so.