GlowWorm Swiftflow 100 - dim and flashing MAINS light

[lotstolearndiy]

I was having a shower and the hot water turned cold and never warmed up again. The pilot light is lit but the burners do not light when I turn on the hot water. There are three lights: MAINS, RUNNING, LOW PRESSURE WARNING. The only one that is lit at all is the MAINS light but it is very very dim (only possible to see with the kitchen lights off). When I turn the water on, nothing happens. When I turn the hot water on very fast the MAINS light goes off. After about a second, it flashes on momentarily and goes off. It repeats this once per second (or a bit slower). It stops doing this when I turn the hot water tap off and the MAINS light is then lit but dim (again).
We have turned the mains supply to the boiler off for about 1 minute and then turned it back on again. No change.
Has anyone seen this before?
Thank you

 

[Agile]

Its not anything very obvious!

Possibly a failed DHW flow switch. Easy enough to check by bypassing it.

Why dont you want to do the normal thing and call an experienced boiler engineer?

Tony

 

[lotstolearndiy]

I am insured and I have booked an engineer's visit. I just like to give the engineer as much of a heads up as possible so that we stand the best chance of him bringing the part that he needs to fix it. We have 5 young children and even a day without hot water is a real pain.
Why would a failed flow switch result in the MAINS light being dim?

 

[penpusher]

As good as your intentions may be, no engineer worth his salt is going to pick up a part on the basis of your diagnosis. Better to leave him (or her) to diagnose the fault and aquire the part needed. I have had various customers telling me that the x is faulty and can I bring x with me? 9/10 times x is fine. You wouldn't be happy if your engineer brings the part that you have diagnosed as faulty, finds its fine and then charges you for the part as he/she's had to fork out for it on your amateur diagnosis, would you? Leave fault finding to the experts!

 

[Agile]

I just like to give the engineer as much of a heads up as possible so that we stand the best chance of him bringing the part that he needs to fix it.

You will upset him if you tell him whats wrong ( in your view ).

It also stirs up the thought that you see anyone mending boilers as an uneducated plumber!

All you need to do is tell him the model and the symptoms!

The mains pilot light is probably dim because its an old neon bulb and they age and become dim. Most likely totally unconnected with the fault!

See if its the flow switch! Thats a specific part for your model and they do often fail. It would be good if he brought one with him but thats unlikely as explained above. An independent engineer would but not an insurance contractor!

Tony

 

[lotstolearndiy]

If the flow switch were the problem wouldn't I expect the central heating to still work (which it doesn't)?

 

[weareleeds]

Is pump running also fan on high speed

 

[Agile]

Possibly a failed DHW flow switch.

Tony

Of course if the DHW flow switch was faulty the boiler would still work on heating.

If you revisit your original posting you were only talking about no hot water. You said nothing about heating.

We cannot make long distance guesses very accurately if you only give us half of the information.

Is it really that important anyway when you have a maintenance contract and the engineer will be on site to properly diagnose the problem?

Tony

 

[lotstolearndiy]

My guess is that it will be the control board.

 

[Agile]

Well as you clearly know more than any of the experts then why not fix it yourself and cancel the insurance?

This is another customer who thinks that all boiler engineers are ignorant plumbers with no education.

It could be the PCB though ( or several other parts too )

Tony

 

[lotstolearndiy]

Tony

You really are very rude. You seem very insecure about your job, your ability and your education. I don't recall at any stage trying to offend you and I certainly never said anything about plumbers being uneducated. My heating engineer does not suffer from your insecurities. He is very well educated. After our telephone conversation he came today with the appropriate parts. We now have hot water again. He was not the slightest bit upset by me trying to understand how the boiler works. I studied engineering at university because I like to know how things work. I will not expurgate this from my personality just so that I do not damage your fragile feelings of self-worth. My heating engineer has no problem with my interest. People like me have not put him out of a job yet. He earns a very high salary. Perhaps he's better than you: I don't know. If you aren't very good at this plumbing lark, I apologise. I should be more sympathetic to your insecurities. Maybe if you ask around on the forums someone could recommend a course of study. I find the habitues of forums to be very helpful and nice (well, most of the time).

By the way, he replaced the printed circuit boards. You see, a faulty flow switch does not cause the MAINS light to behave in the way I described. Don't worry, ultimately you will make it. Just believe in yourself.

 

[ollski]

By the way, he replaced the printed circuit boards.

Did he really replace both boards as it usually only the small mains board which causes the fault.

 

[Soggy_weetabix]

Ollski,

spot on, but I bet lotstolearndiy is happy to spend hundreds of pounds on both pcbs being changed by an engineer who cant ascertian what the real fault was.

pcb probably could have been repaired anyway (but best to change it)

David

 

[First-time-buyer]

You guys are just cruel.

Im glad he had them both changed, at least now if it breaks again next week he can ring the next engineer up and diagnose it for them..



Now, anyone fancy replying to my post.?

 

[Soggy_weetabix]

Yes I do.

Engineers on here give up free time to help people with heating problems.

If they wish to disagree or argue with what has been posted that is their choice.

People like Agile are some of the most experienced boiler repair engineers you will find and their opinion is honest.

If you dont like honesty, go pick up your yellow pages and dont post here.

Just outta curiosity, what is your proffession?

David