Ariston 27 RFFI failing to ignite.

[TheFamousPoohBear]

Ariston 27 RFFI boiler failing to ignite. Gas valve has been changed but no joy. Gas valve solenoid energised and ignition spark for about 8secs. then shutdown after three attempts. Any ideas? Possible board fault? Usual stuff with incorrect diagrams showing valve solenoid having two solenoids but only one of these is connected.
Probably this valve used in different combinations hence the error in the connections to the valve as shown in the diagram supplied.

 

[Agile]

Who changed the gas valve and why?

Tony

 

[TheFamousPoohBear]

Hi Tony,
Thanks for the prompt reply. This was installed by a company based in Bathgate in Scotland just over two years ago at a cost of around £2.5K for the complete installation, some pipe-work and removal of the old boiler. I never heard from them again as regards service provision. As I understand it these installations should be registered by the installer? Anyway the boiler has functioned satisfactorily up till now. I had another corgi registered gas installer to carry out a service but he didn't even take off the boiler covers. I also asked for other gas appliances to be serviced, one with a faulty ignition but this was left unrepaired. All he actually did was to clean out the debris at the back of the chimneys and charged £100.
I have another corgi registered engineer working on it at the moment and both of us are puzzled as to the cause of the problem. I'm an electronics engineer so between the two of us we should be able to come up with an answer.
In my earlier days of working I started as a TV service engineer working for a big TV rental company and saw no end of the cowboys at work in that era. I still get occasional requests from insurance companies to check so called repairs and what I see would make you cry. It seems despite various regulations in place the cowboys have not left the scene!
I can get this engineer to sort the registration out I'm sure but if there is anything more I should do I would appreciate the advice.

 

[Agile]

This is a duplicated thread which is confusing. The other one should be deleted !

Both gas valve operating solenoids are powered but they are either paralleled or series connected at the valve plug. Have you checked the volts on the mod coil? With no volts it should still give the min gas pressure of about 1.5 mB but this might not be sufficient to allow it to fire up.

The vital test is to measure the gas pressure with a water gauge at the INLET to the gas valve as the boiler tries to fire.

I suspect this is falling to zero indicating a blockage in the supply pipe. If so then the pressure needs to be measured at the meter. If OK there then its in the pipe in the house. If it fails there its a faulty regulator or supply to the property.

Your CORGI has almost certainly changed the gas valve when it was not the problem. It always surprises me that so many dont follow their training and do the basic tests to confirm the gas supply is adequate.

Tony

 

[ChrisR]

No, it's just a split thread
//www.diynot.com/forums/viewtopic.php?t=98141

 

[Agile]

This is a duplicated thread which is confusing. The other one should be deleted !

Both gas valve operating solenoids are powered but they are either paralleled or series connected at the valve plug. Have you checked the volts on the mod coil? With no volts it should still give the min gas pressure of about 1.5 mB but this might not be sufficient to allow it to fire up.

The vital test is to measure the gas pressure with a water gauge at the INLET to the gas valve as the boiler tries to fire.

I suspect this is falling to zero indicating a blockage in the supply pipe. If so then the pressure needs to be measured at the meter. If OK there then its in the pipe in the house. If it fails there its a faulty regulator or supply to the property.

Your CORGI has almost certainly changed the gas valve when it was not the problem. It always surprises me that so many dont follow their training and do the basic tests to confirm the gas supply is adequate.

Tony

 

[TheFamousPoohBear]

The CORGI has I think, washed his hands of this problem.
Gas pressure at the valve inlet is 17/18mB, dropping very slightly as the boiler attempts to fire.
On the second attempt by the boiler to initiate ignition, if you shut the supply pipe valve the pressure remains at 17mB dropping to zero when the boiler attempts to ignite, as you would expect, indicationg that the gas valve is opening.
Mod volts are 235Vac on initial startup falling to .05Vac, almost zero.
The next step I think is to get the meter governor checked. This gas pressure is slightly on the low side but I would have thought sufficient to let the boiler fire.
I don't think this esteemed Corgi wants to take this job any further as shelling out 250 smackaroonies for a new board (+ vat of course) and it still doesn't solve the problem is not to his liking. So I'm back to square 1.
Any other ideas you might have are welcome.

I have been an electronics engineer all my life. How these manufacturers justify such high prices for their replacement boards is beyond me.
There is nothing on these board as regards components that are anything out of the ordinary. It's just the usual ripoff by manufacturers that take us all for mugs! I think I'll spend my time repairing these. There has to be a market here and they are certainly not that complex.

 

[Rob]

Volts to the modureg will be in the region of 5-25vdc.

Standing pressure sounds low but aslong as its 18+ on ignition it shouldnt be a problem.

Have you measured the outlet of the gas valve during ignition, this will tell you if its opening or not.

Could this just be a case of blocked injector/ burner ports?

 

[Gasguru]

Find another Corgi that knows what he's doing or phone Ariston for one on their list.

Get the ignition burner pressure checked. This can go out of adjustment on the pcb. Sometimes the pots. are poor quality.

Also check the correct flue restrictor ring has been fitted.

Don't start swapping boards before the basic checks have been done - Ariston boards are noramlly very reliable.

 

[TheFamousPoohBear]

Hi Gasguru et al,
Just an update on this problem.
After nearly 3 months this boiler is still out of commission. Following replacement of the gas valve the control board was also eventually replaced which also failed to work, indicating a completely different fault code(fan not running, an obvous condition). Putting the original board back allowed the fan to run indicating the fault did not lie with the fan. This was taken up with the spares suppliers MJT Controls based in Bristol who replied that another board would need to be purchased and I would need to claim the outlay back if it proved on their examination to be faulty. Not a road I intend to follow at over £300 a throw. The board was returned to them anyway requesting an immediate working replacement but nothing has been recieved over the last nearly ten days, an unaceptable time in my opinion.
The Corgi in question has now left the job leaving the boiler dismantled and still not working. I contacted Ariston directly and they said they thought "the guarantee for 27RFFI series was 5 years but as the original installers (Glowarm) had failed to carry out any service since the installation it would not be covered."
The outcome is that I appear to have no option than to cut the cost and seek a more reliable replacement for this Ariston heap of junk.
If anyone has any advice on a new choice (or even a schematic of the boiler control electronics) it would be gratefully appreciated. It appears that neither the installer or the boiler manufacturer has the slightest interest in assisting with this problem.
As a result I have no option than to advise anyone thinking of using choosing Ariston as a product to seek a more reliable boiler from another manufacturer. My own experience with their service capability and back up, just over a mere two years after installation, leaves the impression one of total disinterest and unreliability.

 

[gas4you]

If you really want to change the boiler go for a Vaillant Ecotec Plus 831.

But surely someone knows how to fix it

17mbar at the gas valve inlet is too low, especially as you say it drops even more when trying to ignite.

It sounds like either the working pressure at the meter govenor is way too low or if it is correct then the gas carcass has been installed too small or not upgraded to a suitable size.

You need to get the inlet pressure correct before going any further.

 

[Agile]

As a result I have no option than to advise anyone thinking of using choosing Ariston as a product to seek a more reliable boiler from another manufacturer. My own experience with their service capability and back up, just over a mere two years after installation, leaves the impression one of total disinterest and unreliability.

I am sorry but I dont think thats fair on Ariston!

They give a FIVE year guaranty on their boilers and only ask you to get it serviced each year which is what any sensible owner would want to do.

The fact its not being repaired free for you is because you did not bother to get it serviced.

I appreciate that you used a second rate installer and a third rate repairer but as a consumer you have to option to consider complaints against them. You have not made it clear but it seems that the gas valve and PCB may not have been bought and fitted by the repairer.

If the repairer had supplied and fitted all the parts then you could refuse to pay for anything as they had not fixed the fault.

Tony

 

[TheFamousPoohBear]

Hi Tony,
Yes, I appreciate your comments on my criticisms of Ariston which are somewhat intemperate, more based on frustration at finding it so difficult to get proper service.
As you say, reliance on installers in the first place that may not be the best in the business is something unfortunately that can only be learned by experience.
The cost of the replacement gas valve was not borne by me but the board is, based on the advice of the corgi who may not have wanted to bear this in case his diagnosis proved unreliable.
It may be merely unfortunate that the replacement board also displayed a fault. This has yet to be resolved by the service agent.
The gas pressure has been checked and found to be within limits. Advice on the bore of the gas pipe supplying the property indicates that the boiler supply requires a increased diameter pipe as indicated in the installation instructions for this boiler which was not done by the installers although that is not the primary problem for the moment.
My thanks to all who have responded to the original query and their much appreciated advice.
I'll keep you posted when and if I get the problem solved.

 

[Agile]

I do have to say that I get the impression that in Scotland the general calibre of boiler engineers is considerably higher than in England.

This is because with a lower population density the engineers rely on word of mouth to gain much of their work and have to give a better service in order to stay viable. News of a bad job spreads quickly.

You should expect that anyone installing a boiler will do the job properly and you have an opportunity to complain to CORGI for many aspects including gas pipe sizing.

When you call someone to repair your boiler you can expect that he will be adequately trained and experienced to find and repair the fault. If he fits new parts which are not required then you shoulf not have to pay for them. Now should you pay for his time when he is unable to repair the fault.

Whilst I feel sorry for you, I dont have any sympathy because you did not get the boiler serviced to comply with the extended warranty.

You did say that you had it serviced once. Presumably that was documented on the Benchmark Certificate. Can you not use that to get Ariston to honour the warrantee>

Tony

 

[Gasguru]

Find another Corgi that knows what he's doing or phone Ariston for one on their list.

Get the ignition burner pressure checked. This can go out of adjustment on the pcb. Sometimes the pots. are poor quality.

Also check the correct flue restrictor ring has been fitted.

Don't start swapping boards before the basic checks have been done - Ariston boards are noramlly very reliable.

You know the gas valve works as the gas pressure drops.

You know the ignition works since you can see the ignition electrodes sparking.

You stated the original problem was a lockout due to the burner not igniting.

Therfore the problem is a failure to ignite the gas

so its either

too much flue draught caused by incorrect flue installation or incorrect flue restrictor ring

incorrect ignition burner pressure

incorrect adjustment of the ignition electrodes

Are you sure you work in electronics? Methodical and logical fault diagnosis is common to all industries - why are you not applying the same procedure for your boiler?

You have incurred the cost of a gas valve and PCB even though the symptoms do not point to problems with these components and you seem reluctant to check the most basic items.