I went to this one a couple of weeks ago and as there was a noise like noisy bearings coming from the fan area of this boiler i got a new fan for it. Went to fit it today and it hasn't cured the problem. This boiler is fine on DHW but on CH it fires up and after about 10 secs or so it goes to a low flame and then either picks up or gets so low that it goes out. After about a minute it fires back up and does the same again. I thought (with the noise it was making) that the fan was on its way out but i was wrong. Has anyone any other ideas. Pump is a little noisy and when i took the central screw out black water came out. Pump is working. Now i'm thinking that maybe the CH flow filter may be blocked? Tennant has had everything changed on this monster apparently. PCB a couple of times. From reading some of the posts it seems Gloworm have had problems with PCBs on microns? Originally the bloke at the house had put a cowl over the end of the flue so i took that off but it didn't make a lot of difference. Also it is in a ground floor flat and it feeds rads for 3 floors above also. I'm guessing that all the tennants must share the bill. Any ideas anyone?
Gloworm Compact 80e problem
- Thread starter Jezzy
- Start date
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Blocked RETURN filter in lower pump connection - messy job.
Noise may be kettling as the burner fires at maximum rate and will be slow to modulate down now that boiler is getting on.
Expansion vessel probably flat as well - valve access poor.
Noise may be kettling as the burner fires at maximum rate and will be slow to modulate down now that boiler is getting on.
Expansion vessel probably flat as well - valve access poor.
The PCB on a Compact is a lot more reliable than the early Micron ones, but they do go now and again like most others. It almost sounds like its kettling which happens awfully quickly on small heat exchangers, which suggests you are on the right track with pump & CH circulation..particularly as it seems to work OK on DHW when it can get the heat away.
One slight puzzle..if the system is crudded up, how come the plate to plate works, as that is usually the first casualty of muck in the system.
I had a Compact earlier this year that MELTED its venturi, but by and large we don't have too much trouble with them..except diaphragms.
Alfredo
One slight puzzle..if the system is crudded up, how come the plate to plate works, as that is usually the first casualty of muck in the system.
I had a Compact earlier this year that MELTED its venturi, but by and large we don't have too much trouble with them..except diaphragms.
Alfredo
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Its the DHW heat exchanger, made up of a series of metal plates pressed together with lots of quite narrow water passages. It provides the interface between the hot boiler water and the cold mains water without the two actually meeting, and by the time the cold water passes out the other side..its hot..in about 3 seconds or so. You can see it at the back behind the two diaphragm micro switches on a compact 80E..looks like a small silver brick. Similar set up on majority of combis.
Alfredo
Alfredo
Yes i know where the DHW heat exchanger is and what it looks like and does but with you saying it was the first to get crudded up it confused me as i thought that the main heat exchanger would crud up first even though its much larger as whenever i unscrew the cap from a pump, there is nearly always black water that comes out but you very rarely get black water coming out at the taps.
Anyway, on another thread, i also went to a vokera 80sp today that won't fire up at all. When i took the covers off there was everything in there but the actual bird (it was like a nest). After i cleaned it all out it still wouldn't work and the fan isn't revolving at all so i'm gonna order a new fan for that one also but am a bit sceptical now as the new fan on the compact hasn't cured it. The fan in the vokera should run constantly though but on an earlier thread someone had mentioned a 580kohms resistor that might be the prob. I don't want to splash out £55 for a new fan if it might not be at fault, although it is a bit stiff when i try to spin it manually.
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Jezzy said:
So, who paid for your incorrect diagnosis ?
Anyway, on another thread, After i cleaned it all out it still wouldn't work and the fan isn't revolving at all so i'm gonna order a new fan for that one also
HAve you actually checked whether you have volts to the fan ?
Jezzy you need to get on a boiler diagnostics course - fans are easy to test with a test lead (plug on one end, croc clips on the other) - the resistor is switched in to provide a constant low speed operation for purging the combustion chamber. The impeller should spin easily
Back to the Compact:
The black water in the pump is completely seperate thant the hot water circuit.
The return filter is located in the lower pump connection (see the manual page 37?). You have to remove the plastic elbow from the pump to to the return valve at the back. If the filter is blocked as you remove it water above it will pour out.
Drop the pressure and re-charge the expansion vessel - you will need about 300mm clearance on the left hand side. This is to get the club hammer and chisel in. You have to knock a lump out the wall behind to enable you to get the pump on the valve - great design.
If the flow and return pipework has a sufficient rise up to the boiler you can probably work on the boiler with the system full of water.
Touch the isolating valves at your peril.
Be aware these boilers use an unusual gas valve - check the max and min burner pressure on both DHW and heating - they often go off spec (higher).
The plate to plate is the heat exchanger that transfers heat from the main heat exchanger at the top to the domestic water. They are prone to blocking if the system water is sludged. Easily checked by the method in previous posting. Heres one blocked after only 3 years in a new build house.
Note how the primary side flow cconnection is full of scale picked up from the corroding radiators (3 years old).
Back to the Compact:
The black water in the pump is completely seperate thant the hot water circuit.
The return filter is located in the lower pump connection (see the manual page 37?). You have to remove the plastic elbow from the pump to to the return valve at the back. If the filter is blocked as you remove it water above it will pour out.
Drop the pressure and re-charge the expansion vessel - you will need about 300mm clearance on the left hand side. This is to get the club hammer and chisel in. You have to knock a lump out the wall behind to enable you to get the pump on the valve - great design.
If the flow and return pipework has a sufficient rise up to the boiler you can probably work on the boiler with the system full of water.
Touch the isolating valves at your peril.
Be aware these boilers use an unusual gas valve - check the max and min burner pressure on both DHW and heating - they often go off spec (higher).
The plate to plate is the heat exchanger that transfers heat from the main heat exchanger at the top to the domestic water. They are prone to blocking if the system water is sludged. Easily checked by the method in previous posting. Heres one blocked after only 3 years in a new build house.
Note how the primary side flow cconnection is full of scale picked up from the corroding radiators (3 years old).
Thanks for replies, they will give me something to go at.
Got a running 80sp fan in the garage you can have for nowt if you`re near wakefield? Thanks for that Strachan, i'm at Agbrigg - but not one of the locals, If you let me know where you are i will come and pick it up. Yes i do need to go on a boiler diagnostics course. The one i am thinking of is at Sheffield at a company called Gleesons. it's a 5 dayer, 2 1/2 days on part p electrics and the rest on boiler fault finding. £500 plus obviously a week without pay also (whilst i'm there). Has anyone been on this course? Also seen the mr combi course down at milton keynes in the Gas installer / corgi magazine advertised for £95 for a one day course. About the heat exchangers - as they are 2 completely separate systems, are you saying that clean mains water has done all that damage in 3 years then? Didn't think that would be possible. You live and learn! I haven't been paid at this company yet so i might be footing the bill for the fan! The tennants don't pay, but their landlords do and obviously will get it back from the rent eventually.
Got a running 80sp fan in the garage you can have for nowt if you`re near wakefield? Thanks for that Strachan, i'm at Agbrigg - but not one of the locals, If you let me know where you are i will come and pick it up. Yes i do need to go on a boiler diagnostics course. The one i am thinking of is at Sheffield at a company called Gleesons. it's a 5 dayer, 2 1/2 days on part p electrics and the rest on boiler fault finding. £500 plus obviously a week without pay also (whilst i'm there). Has anyone been on this course? Also seen the mr combi course down at milton keynes in the Gas installer / corgi magazine advertised for £95 for a one day course. About the heat exchangers - as they are 2 completely separate systems, are you saying that clean mains water has done all that damage in 3 years then? Didn't think that would be possible. You live and learn! I haven't been paid at this company yet so i might be footing the bill for the fan! The tennants don't pay, but their landlords do and obviously will get it back from the rent eventually.
Be aware these boilers use an unusual gas valve - check the max and min burner pressure on both DHW and heating - they often go off spec (higher).
How can i check the min and max settings when its firing up and then almost immediately going down to a low flame before switching itself off as the flame fades away to nothing in approx 5-10secs? I could check the max setting if i'm quick but its like its modulating all the way down to zero.
How can i check the min and max settings when its firing up and then almost immediately going down to a low flame before switching itself off as the flame fades away to nothing in approx 5-10secs? I could check the max setting if i'm quick but its like its modulating all the way down to zero.
[email protected] e-mail me jezzy and i`ll sort that fan out for you, and any other bits you want off it. It ran fine apart from heating, customer didn`t want it repairing, threw a new vaillant on the wall for them.
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