I posted earlier regarding some problems with a Glow-Worm 40FF boiler on an open-vented system. We have no hot water cylinder, just the boiler, a Grundfos pump and a fill/expansion tank in the loft.
Summary to date:
Radiators were working for the most part, but the radiators upstairs had a fair amount of air in them. We bled the radiators about a month ago, and that's where the problems started.
First, the downstairs radiators stopped working entirely - they were constantly dead cold. Went through all the steps -
1. Checked the fill/expansion tank (which did not have enough water in it; the valve had stuck shut. This has been resolved; the valve is now functional and the F/E tank has water in it.).
2. Bled the pump just in case.
Then the upstairs radiators started going funny - the top and sides were warmish, but the middle and bottom of the radiators weren't. So we checked and found that this could be due to sludge (presumably dislodged by refilling the boilers with water instead of having air space in them).
So yesterday we put a bottle of de-sludging solution in the F/E tank, after following the directions, shutting off the central heating and letting it cool completely before adding the chemical.
Turning on the heating afterwards, we have noticed the following:
1. The pump appears to run regardless of whether the boiler is on or not. The cable from the pump goes into a standard wall socket, and if I put my fingers onto the control dial on the pump I can feel it vibrating.
2. The boiler will light - you can hear it fire up - and then makes a low vibrating noise for a while, accompanied by a higher-pitched rattling noise (a fan?) and a little bit of "pinging" - sort of like the sound you get when you start heating up a deep-fat fryer. During this, the Boiler On LED is lit.
3. After two or three minutes, the Boiler On LED goes out and there is no further noise from the boiler.
4. The pipes running from the boiler to the pump do not get warm in the time the "Boiler On" LED is lit.
5. If you switch off the boiler and the mains connection, then switch it back on, the boiler does not respond. It has to be left a couple of hours before it'll try firing up again.
Any diagnostics anyone could provide so that when I contact someone to come out and look at this (I really, really can't afford a new boiler install right now... ) I can make intelligent suggestions (and anything I can try myself would be appreciated too) I'd be very grateful.
Summary to date:
Radiators were working for the most part, but the radiators upstairs had a fair amount of air in them. We bled the radiators about a month ago, and that's where the problems started.
First, the downstairs radiators stopped working entirely - they were constantly dead cold. Went through all the steps -
1. Checked the fill/expansion tank (which did not have enough water in it; the valve had stuck shut. This has been resolved; the valve is now functional and the F/E tank has water in it.).
2. Bled the pump just in case.
Then the upstairs radiators started going funny - the top and sides were warmish, but the middle and bottom of the radiators weren't. So we checked and found that this could be due to sludge (presumably dislodged by refilling the boilers with water instead of having air space in them).
So yesterday we put a bottle of de-sludging solution in the F/E tank, after following the directions, shutting off the central heating and letting it cool completely before adding the chemical.
Turning on the heating afterwards, we have noticed the following:
1. The pump appears to run regardless of whether the boiler is on or not. The cable from the pump goes into a standard wall socket, and if I put my fingers onto the control dial on the pump I can feel it vibrating.
2. The boiler will light - you can hear it fire up - and then makes a low vibrating noise for a while, accompanied by a higher-pitched rattling noise (a fan?) and a little bit of "pinging" - sort of like the sound you get when you start heating up a deep-fat fryer. During this, the Boiler On LED is lit.
3. After two or three minutes, the Boiler On LED goes out and there is no further noise from the boiler.
4. The pipes running from the boiler to the pump do not get warm in the time the "Boiler On" LED is lit.
5. If you switch off the boiler and the mains connection, then switch it back on, the boiler does not respond. It has to be left a couple of hours before it'll try firing up again.
Any diagnostics anyone could provide so that when I contact someone to come out and look at this (I really, really can't afford a new boiler install right now... ) I can make intelligent suggestions (and anything I can try myself would be appreciated too) I'd be very grateful.
