Glow-worm Micron 60 Boiler problem

Steve_xx

We have a Glow-worm Micron 60. When it fires up it only stays on for approx 30 seconds before shutting off. Then it comes back on after about 15 seconds and then off again within 30 seconds and so on.

Got a local plumber out today who replaced the circulating pump. The problem remains. He's now talking about flushing the system, but we haven't got that far yet.

I'm inclined to think that the problem might be within the boiler rather than with the circulating pump and I'm not convinced that flushing the system will cure it since we always ensure that it has inhibitor in it to prevent any sludge build-up.

Does anyone have any advice on what might be the problem?

Crabman

Do you have LEDs on the front of the boiler? If so, do they flash when the boiler switches off? If so, try and cross-check with your manual as our Micron boiler has two LED lights. Depending on the flashing combination it points to different faults which should help.

Our old boiler had a fault where it shut off after about half a minute, it turned out to the the thermocouple which was a easily replaced by our engineer.

I'm presuming there was some reasoning behind your plumber's decision to replace the pump and that he has already checked that the boiler is functioning correctly?

P.S: Don't forget to check that he (or anyone else) is GasSafe registered (previously CORGI).

Steve_xx

Yes this model has two LED's on the front of it. The red reset one is off and the green 'burner lit' LED comes on when the burners are on and then goes off when the burners do.

The plumber very quickly concluded that it was somehing to do with the pipeflow. Therefore he decided to change the circulating pump.

He is GasSafe registered.

gas4you

Some Micron boilers control the pump from the pcb. Has he checked that power is getting to the pump?

Failing that it could be a flame rectification problem perhaps.

Steve_xx

gas4you wrote: »

Some Micron boilers control the pump from the pcb. Has he checked that power is getting to the pump?

Failing that it could be a flame rectification problem perhaps.

Yes he's checked that and replaced the pump. The pump is working. I think the original pump was fine. The radiators do get warm, but only slowly, I guess due to the fact that the boiler shuts off in 30 second increments.

You mentioned "flame rectification". Could you expand further on this please?

Also, I was wondering if the problem could be thermistor related?

Crabman

After the burner shuts off, do both lights remain off? If so your plumber could be right and the fault could lie elsewhere. It's difficult to say though.

What may be an option, if you're not sure about having a system flush, is contacting Glow Worm to ask their technical help department for advice:

http://www.glow-worm.co.uk/contact-us/

Steve_xx

Crabman wrote: »

After the burner shuts off, do both lights remain off? If so your plumber could be right and the fault could lie elsewhere. It's difficult to say though.

What may be an option, if you're not sure about having a system flush, is contacting Glow Worm to ask their technical help department for advice:

http://www.glow-worm.co.uk/contact-us/

Yes both lights remain off when the burners are off.

I've emailed Glow-worm to see what they think about it.

Steve_xx

update:

The plumber came back today and he connected the garden hose to the outlet valve, ie the valve that you open to drain the system, and he turned the cold water on because he thinks there is an air blockage in the pipework. His efforts resulted in no improvement and the intial problem exists. He said to run it for a couple of days to see if it clears up.

In addition to this he changed the pump yesterday because he said that no heat was evident on th radiator side of the pump. This is strange since the radiators were heating up albeit slowly due to the fact that the boiler keeps shutting down.

This evening I thought I'd take a look at it. I changed the pcb because I had a spare one that had a different problem on it before it was replaced. When I changed it I found no improvement and the boiler still cycles on and off. So I guess I can conclude that it's not the pcb that's at fault. There are other components in there and I'm wondering if it could be one of those. There will no doubt be something in there that senses the temperature. I don't know where that might be or what it might be called but I feel that might be the problem.

aboard_epsilon

at £30 plus an hour .,..shouldnt he doing better than that ..

bet there are some out there ..for the same charge would have nailed it in the first mins of the visit .

all the best.markj

gas4you

Is this fault occuring on hot water as well as heating?

Steve_xx

gas4you wrote: »

Is this fault occuring on hot water as well as heating?

Sorry, I missed your response. Yes the fault is with both heating and water. There has been a development and I think I've found the problem.

As you know from my earlier post, the plumber thought it was a pump problem and so he replaced it and I paid him £110 in total. But the fault remained. Even worse, the replacement pump was not brand new. It was obviously secondhand as it was scratched and the cover for the electrics was snapped off of it. When I looked closely at it I could see that the cover that he'd left didn't actually belong to the pump.

I called him back to try and locate the problem, which he insisted was due to an airlock in the piping, and also I wanted an explanation about the age and newness of the pump he'd fitted. He assured me that it was brand new and that he could supply a receipt for its purchase; but this evidence did not materialise.

On Friday, still convinced it was an airlock that was causing the problem, he decided to connected a hosepipe to the system drain plug and then fed it with cold water from the mains. He told me to run the system over the weekend and see how it went. If it didn't sort itself out he was going to bring some kit on Monday to flush the whole system out. The problem remained.

Over the weekend I had a look at it myself. I removed the front of the boiler and by doing so the problem stopped. A plumber friend and I have therefore concluded that the fan on the top of the boiler, though running, is not running fast enough or it may be stopping intermittently, thus starving the boiler of fresh air. Therefore the fix seems to be a new fan.

Today I called the plumber and I asked him to come and see me which he did. When he arrived, supposedly as he thought, to flush the system out, I told him that I wanted him to fit the new pump that I'd paid him £110 for and that I wanted that to be the end of it. He agreed to do it and I witnessed a new pump coming out of his van and out of it's box. However, the Gunfoss pump he had quoted £69+VAT for had now changed to another brand that I note the price is around £30 + VAT when I look on the internet.

I didn't mention that I had found the fault as I was thoroughly fed up with the whole thing. God knows how long he could have dragged this out. In effect I have had a lot of hassle and probably a new pump that was not needed. I still have the original problem, though i now know what it is, and I'm £110 lighter.