Hi
I wonder if anybody can throw light on my little problem:
I have a conventional vented fully-pumped CH/HW system, using a Glow-Worm 18hxi, 2 motorised valves and Honeywell Auto by-pass valve. The layout is generally as the image. The boiler is wall-mounted on the ground floor, all of the controls are in the airing cupboard on the first floor, and the FE tank is directly above the airing cupboard in the loft.
//media.diynot.com/133000_132467_17648_88451480_thumb.jpg
The problem is intermittent over-flow from the FE tank. It seems to occur in the 'over-run' stage of the cycle, when the controls and boiler have switched off, but the pump (electrical feed from the boiler) is continuing to operate.
I have a feeling it's to do with the setting of the by-pass valve, but I cannot reproduce the fault on-demand. I've put it in over-run mode when fully hot, with the by-pass valve either fully open or fully-closed, but it all works OK and no overflow. The system generally is working fine. I can hear the MV's operating, and the pump is the correct way round.
I've checked the ball-valve in the FE tank, and that is OK, plus it only seems to happen when the pump is running.
And then, occasionally, there's a cry from the kitchen "It's leaking again !"
I can't work out any scenario of what could be causing it, and why it can be so intermittent ...
I wonder if anybody can throw light on my little problem:
I have a conventional vented fully-pumped CH/HW system, using a Glow-Worm 18hxi, 2 motorised valves and Honeywell Auto by-pass valve. The layout is generally as the image. The boiler is wall-mounted on the ground floor, all of the controls are in the airing cupboard on the first floor, and the FE tank is directly above the airing cupboard in the loft.
//media.diynot.com/133000_132467_17648_88451480_thumb.jpg
The problem is intermittent over-flow from the FE tank. It seems to occur in the 'over-run' stage of the cycle, when the controls and boiler have switched off, but the pump (electrical feed from the boiler) is continuing to operate.
I have a feeling it's to do with the setting of the by-pass valve, but I cannot reproduce the fault on-demand. I've put it in over-run mode when fully hot, with the by-pass valve either fully open or fully-closed, but it all works OK and no overflow. The system generally is working fine. I can hear the MV's operating, and the pump is the correct way round.
I've checked the ball-valve in the FE tank, and that is OK, plus it only seems to happen when the pump is running.
And then, occasionally, there's a cry from the kitchen "It's leaking again !"
I can't work out any scenario of what could be causing it, and why it can be so intermittent ...