Problem with Combi boiler - BG/Worcester/Bosch RD532i

Morning,

I'm hoping you good people/plumbers/central heating experts can help

I had my combi serviced yesterday by a Central Heating 'Engineer'. I was at work but the missus was in. Once finished there was an intermittent fault. The CHE said it was probably already there and was coincidental with him removing and replacing the boiler cover during the service.

He used the manual and support telephone number and ended up whipping his multimeter out for testing. He said it was the HT wire/cable that is broken and will need replacing (about £40) but as the boiler was a British Gas make and model and installed and supplied by BG he couldn't do anything else. He did try a local parts place for a spare but they didn't have one in. He also said just keep pressing the reset button to clear the fault until you get it sorted.

Not very good is it? Service a boiler, leave it with an intermittent fault and then essentially wipe your hands of it all...

Down to the details:

British Gas supplied and installed about 5 years.

Make and model = Worcester/Bosch RD532i
Other details on the plate - GC NO. 47 10810. 109 FD 488 and then the serial number 06xxx

The fault indicated on the display is 'FA' which according to the manual is "Flame detected after shutoff". Suggested actions in the manual are "Check gas valve and wiring to gas valve. Clean condensation trap and check electrode assembly. Flue clear?"

The fault appeared after trying the hot water tap last night. I had to reset it a couple of times and it was okay this morning for a shower.

Any ideas? Is it safe to use in the mean time? Was he telling the truth? What is a HT wire? He explained it as the same as the HT leads in a car? Providing a high voltage to the boiler.

Regards,

Kris.

The indicated fault is potentially dangerous as it can ( if true ) indicate a faulty and leaking gas valve. Thats a very rare condition though! nothing the service is like to have caused.

This is the problem we have!

Owners call us to "service" a boiler and then expect us to reattend free to deal with ( pre-existing but not disclosed ) faults. I am not suggesting you have done this but many people so it !

It seems totally coincidental based on what you have told us.

If thats really the fault ( which I doubt ) then the HT lead has nothing to do with it.

I expect its really an ignition failure and you have misread the codes! In that case the HT lead could easily be the cause.

Tony

Hi Tony,

Thanks for the response.

Agile said:

Owners call us to "service" a boiler and then expect us to reattend free to deal with ( pre-existing but not disclosed ) faults. I am not suggesting you have done this but many people so it !

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As an aside, I note you've emphasized the word "service". Does that imply a boiler doesn't servicing and it's all a con?

I would not expect a free fix for a pre existing fault. For the record, the boiler was working fine with no error codes whatsoever. There was no problem with it. It hadn't been serviced for at least 3 years (since we bought the house).

So, pre service - no problems. Post service - problems. A major problem where the boiler stops working. Not a fault that could be ignored pre service. Hence my consternation.

It seems totally coincidental based on what you have told us.

If thats really the fault ( which I doubt ) then the HT lead has nothing to do with it.

I expect its really an ignition failure and you have misread the codes! In that case the HT lead could easily be the cause.

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I would think it is difficult to mis-read the code as it's the only thing on the display in big bold letters. And I double checked it. And it is the code he told and showed the missus.

So, what should I do now? Do I get him back to fix it (labour free but parts at whatever cost, or labour and parts at whatever cost), do I have to fork out for British Gas to come out or get another CHE to look at it?

Regards,

Kris.

Is it FA or F7? F7 is flame detected even though appliance switched off. In which case the electrodes are a good bet or a dry joint on pcb. Check flue is clear also. FA is flame detected after shut off yes. Now this could be as tony says the gas valve passing or even the wiring to it. Also needs the condensate trap checking and again the electrodes. Can you smell gas at the flue after it's shut off?
If he's 'serviced' it he could have buggered the electrodes if he's taken them out. Also caused by moisture build up on electrodes after a demand. They should be checked for soundness and that he hasn't mucked up the CO2 ratios. He may have also messed up the fan over run timer on the pcb parameters if he's been messing about with what he obviously doesn't understand. Even though it has our (BG) name on it it is just a Worcester and parts are easily obtainable.

There are some inconsistancies in what has been said.

If thats the fault code then the ignition lead has nothing to do with it. It would be a faulty PCB ( misreading the fault ) or a faulty gas valve ! Both expensive! Neither likely to have been caused by a normal boiler service, but its a strange coincidence! Unlikely in my view to be anything to do with the electrodes but it might be.

I find it hard to imagine why an RGI would make such a simple mistake if he saw that code! The ignition lead is just that.

Now about servicing and repairs. We charge from £55 for a service but from £84 for a repair! They are not the same thing and need a lot more skill to diagnose faults.

A service is a routine checking of the boiler and we do it when we can fit it in and about 7-10 days after anyone calls us. A repair is exactly that and we come the same day when possible.

I cannot suggest what you should do as I find the facts strange to say the least and suspect that there is more involved than has been said.

Tony

Thanks for the reply Dave.

davebgas said:

Is it FA or F7? F7 is flame detected even though appliance switched off. In which case the electrodes are a good bet or a dry joint on pcb. Check flue is clear also. FA is flame detected after shut off yes. Now this could be as tony says the gas valve passing or even the wiring to it. Also needs the condensate trap checking and again the electrodes. Can you smell gas at the flue after it's shut off?

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Definitely FA. I can't smell gas in the utility room or around the boiler. I haven't actually got on top of the boiler to smell around the flue though!

If he's 'serviced' it he could have b*****r the electrodes if he's taken them out. Also caused by moisture build up on electrodes after a demand. They should be checked for soundness and that he hasn't mucked up the CO2 ratios. He may have also messed up the fan over run timer on the pcb parameters if he's been messing about with what he obviously doesn't understand.

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Not something that can be done by me?

Even though it has our (BG) name on it it is just a Worcester and parts are easily obtainable.

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That's what I thought but he was unable to find a spare part (HT cable/wire is what he said) from whoever he rang.

If it really is burning after shut off then there will not be any small of gas because its being burnt.

I dont expect it is burning though because thats so rare.

Whilst something do do with the electrodes would seem appropriate I cannot see how the flame rectification could be fooled into thinking there is a flame when there is none beause there would be no rectification process on dirty electrodes. In any case he is expected to clean the electrodes on a service.

The last time I saw a BG badged Worcester it still had the basic Worcester model detains on the inside!

Tony

Hi Tony,

Agile said:

There are some inconsistancies in what has been said.<snip>

I find it hard to imagine why an RGI would make such a simple mistake if he saw that code! The ignition lead is just that.

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As I've said, I wasn't there but the missus was and he spoke to her about the problems. The information I have (again):

The fault code is FA (pointed out by CHE to the missus in the manual) and seen by me when the fault happened again in the evening when I got home. A 'reset' clears it. The testing of a wire/cable with a multimeter was done by the CHE after the fault occurred which was after the service, and after the CHE spoke to someone on the phone (I guess technical support) from a number from the manual/installation/servicing manual the missus gave him as requested. Boiler started working again and CHE left saying if it continues to fail then use the reset and get BG to change the HT wire/cable because he couldn't get one.

Now about servicing and repairs. We charge from £55 for a service but from £84 for a repair! They are not the same thing and need a lot more skill to diagnose faults.

A service is a routine checking of the boiler and we do it when we can fit it in and about 7-10 days after anyone calls us. A repair is exactly that and we come the same day when possible.

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I understand the difference as I'm a network techy and problem solving/support is part of my job Do you fancy a ride to Scunny to sort this one out please?

I cannot suggest what you should do as I find the facts strange to say the least and suspect that there is more involved than has been said.

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The information I've given is what I've been told by the missus (who was told by the CHE) or she's seen him do, and what I've seen when I've been home. I'm not making things up to suit as I know it doesn't help when trying to fix problems. There are two other bits of info which I've not told because I don't think they are relevant but here goes...

The first job the CHE had to do was replace two weeping compression joints with a soldered joints on the hot and cold water pipes - a leftover problem from a new utility a couple of years ago where we moved a sink unit and these were the feeds. Interestingly, the CHE had drained down some of the CH for this job before he cut these water pipes and then wondered why he got wet - they weren't for the CH!! Obviously didn't listen when the job was described.

The second bit of info is that the pressure on the boiler drops about 0.5bar over the course of a few weeks. Obviously a leak somewhere but not an obvious one. The CHE was told about this before he started.

So, apart from that there is nothing more involved from my side.

Any more ideas or do I just call another CHE?

Cheers,

Kris.

I think that info is relavant because it helps me to place this CHE in a nupty classification!

The leaking system water I cannot see any connection at the moment.

I think that a local COMPETENT boiler engineer would be a good idea to come and see just whats going on. He will need to know the Worcester model before he comes.

Can you open the front case and see if its got any Worcester model numbers on the inside?

Can Dave from BG decode the BG markings into a Worcester model number?

Tony

Agile said:

I think that info is relavant because it helps me to place this CHE in a nupty classification!

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Oh dear

The leaking system water I cannot see any connection at the moment.

I think that a local COMPETENT boiler engineer would be a good idea to come and see just whats going on. He will need to know the Worcester model before he comes.

Can you open the front case and see if its got any Worcester model numbers on the inside?

Can Dave from BG decode the BG markings into a Worcester model number?

Tony

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The details on the sticker/label under the pop down lid of the front control panel are, as said above,

Make and model = Worcester/Bosch RD532i
Other details on the plate - GC NO. 47 10810. 109 FD 488 and then the serial number 06xxx

Or do you mean take the white metal case off from the boiler and have a look inside?

Yes, I meant the outer case if you can safely remove it.

I think the one I went to was the same but I dont remember the Worcester model. I think it needed a new gas valve. I repair boilers based on the insides!

Tony

its just a worcester greenstar HE. 32kw model. theres little point in looking on the data badge for the worcester model number as it will just say zwbr 7-25 or some similar nonsense that even worcester callcentres dont recognise. the worcester boiler number is likely to be 4731144.

im willing to bet the electrodes are gubbed, thats pretty much all that goes wrong with the ignition on these. there are two part numbers and as you have handily given us the serial number the part number you require is worcester number 8-718-107-078-0 or GC number E74535. thats for boilers up to FD885. think they are around £40.

nickso said:

the part number you require is worcester number 8-718-107-078-0 or GC number E74535. thats for boilers up to FD885. think they are around £40.

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Someone still had their laptop on! At the time this was posted i was still in scunny! If only id know, i have the electrodes on my van i think

petit_pablo said:

nickso said:

the part number you require is worcester number 8-718-107-078-0 or GC number E74535. thats for boilers up to FD885. think they are around £40.

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Someone still had their laptop on! At the time this was posted i was still in scunny! If only id know, i have the electrodes on my van i think

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nah, thats off the top of my head.

Thanks for the help chaps. I've had no problems since Monday night which was the day the CHE did his stuff.

I took a few pics last night. I've marked up the cable he tested with his multimeter and said he found a fault on. I've also included another label even though nickso says he doesn't need it

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Cheers,

Kris.