biasi boiler problem

[johnm1874]

Hi,
I am having a problem with my Biasi 32s combi boiler,
It fires up for about three seconds shuts down and the lock out light flashes four times but doesn't stay lit, then goes through the cycle again and again, it smetimes works ok but after about an hour it starts this again,
Had a chap out who has tried a few sensors but things seem to be pointing towards the pcb,
anyone got any ideas please?

 

[Boilerman2]

Has your RGI checked the Air Pressure Switch??

 

[Agile]

Unfortunately there are more than one boiler model which includes a 32S. Could you quote the full model number.

I dont like making any suggestions until I know exactly which model is involved.

Depending on model there should be three lights on the left hand side. Its exactly what each one is doing which indicates what the boiler thinks is wrong.

Tony

 

[johnm1874]

Thanks for your replies chaps,
Tony,I shall revert back with the model number asap,
The biggest problem has been that the fault is not always there, ie when the chap serviced it it was fine, at that time but as I had described the fault the chap changed a wee sensor part that goes beside the flame, (flame sensor?) and as he touched it it appeared to have a bad connection, however once again after he had gone it came back again, seems to be after the heating has been on for an hour or so?
he checked out some other sensors and a switch on the Hydraulic diafragm etc and they are showing on the meter what the manual suggests or doing what they are meant to do?
There are three lights on the left hand side of the board one which flashes green during operation, but the other two beside it didn't light at all?
only the one further over that flashes four times red which is the lock out light.
to be fair the chap has kind of exhausted all avenues he can think of I think other than the board, which is an expensive change out if it turns out not to be that.
I apologise if I am not describing things properly as you will no doubt be aware I am not a boiler technician, although the chap carrying out the work is a safe gas registered guy

 

[johnm1874]

Tony,
The Model number of the boiler is M90E - 32S
GC 47 - 970 - 21,
It's all I can see on it,
Thanks,
John

 

[johnm1874]

Thanks boilerman 2,
I beleive he checked the air pressure switch yes!

 

[Agile]

Unfortunately your descriptions are not being terribly helpful.

However, first I need to know the manufacture date. Thats the last four digits of the serial number.

The key to what may be wrong lies in teh three lights and EXACTLY what they show during this fault.

You seem to be saying the lockout light in the centre is flashing four times.

Under normal operation that does not flash but it can flash as part of the setup procedure on the later single PCB versions.

Its quite possibly a single PCB which does have an intermittent fault OR it has been fiddled with and a setup has not been completed.

There is a possibility that if you removed to power supply to the boiler for an hour or two then it just might solve the problem when its repowered.

Tony

 

[johnm1874]

Thanks for that Tony,
The serial number is N009660307 GB
i think it has just one board,
the three lights, only the left hand one which when it is assembled can be viewed was flashing green the other two remained unlit, this was when the problem was present.
the unit was fitted in may 2007 and has worked fine up until now?
The only other thing that may or may not have any bearing on this was about three weeks ago, thinking back to when the problems started, unbeknown to me my sister had topped up the water pressure and when it was hot it started blowing off outside, it seemed to have settled but was still at 3.5 bar when hot not sure if that could have caused any problems.
the engineer has lowered the pressure so as when it s at max temp it is 2.5 bar now

 

[Agile]

The pressure is not relevant.

It should be the single PCB at that date.

its possible to drill two extra holes to view the other lights but the pCB has to be adjusted to give the full fault code display.

If that engineer had any idea he would have done that to help him diagnose the problem.

Tony

 

[johnm1874]

Hi Tony,
I assume the manual will tell the chap how to get the board into the diagnostics mode?
Your help is appreciated

 

[Agile]

I am asuming your boiler has the original single PCB which is effectively an amalgamation of the original two PCBs with little other design changes. It has a 4 way DIP switch.

I think there have been at least two other later PCBs made but some/all are not interchangeable as the boiler side plugs are different. The later ones have to be set up in software by fiddling with the controls on the panel.

It can be done on a short term basis by moving any one of the four DIP switches and back again while the boiler is powered.

It can be done permanently by moving one of the links on the 9 pin jumper line so that instead of joining 7-8 it then joins 6-7.

If you are handy you could drill two more 2mm holes to view the other two LEDs. Its essential to prevent the drill jumping through when the hole is breached. A piece of suitably cut tube on the drill will help.

Then you can move the jumper but in that case with the power off.

You can ask if the engineer knows how to put the boiler into the diagnostic mode. Its all in the book but there is a culture of expecting to fix boilers without reading the book. Thats OK for those who know how they work but most dont.

Tony

 

[johnm1874]

The chap is coming back on Monday so he will put it into diagnostics and see what happens from there,
Thanks for your advice and help

 

[transam]

I don't think that this imfo is in the service manual ??? ,on the single pcb ?? model's that I am aware of there are no dip switches ?? BI 1715 105 pt no , or 9 pin jumper ???

 

[Agile]

I don't think that this imfo is in the service manual ??? ,on the single pcb ?? model's that I am aware of there are no dip switches ?? BI 1715 105 pt no , or 9 pin jumper ???

This thread is about an M90 which is why I am always so keen to get the OPs to quote the exact boiler model so no confusion should then exist.

The BI 1715105 is used on the M96 and all settings are in software.

The OP's boiler uses the first single PCB which is pretty much just an amalgation of the two single boards. Later versions were another unique design and some are a little difficult to set up.

The OP's MI are here:-

http://www.biasi.co.uk/images/manuals/RIVA_COMPACT/SERVICE/4106 EDITION.pdf

The settings start on page 14 but I have already quoted the two ways to get into whats needed to activate the diagnostic mode.

The part number of his PCB is BI 1885101 just in case he needed to get a replacement although THIS version is very reliable unlike the later ones so I rather expect its another fault but obviously that needs to be properly diagnosed.

Tony

 

[transam]

Well u live & learn , not seen this one before , I apologise , should have kept my nose out ,(I will quietly go away !!!)