Problem with plumber/boiler

[scott1980]

Hello all,

We've had a problem with our Biasi M90E since Monday morning. Basically, we've had no hot water or heating since then. I had a look at the boiler on the Monday morning and it seemed to be lighting the gas for a split second then going out, eventually going into lockout. I tried a couple of times with the hot water and central heating but with the same results. I switched it off, went to work and tried it again on returning home and it worked for a short time before eventually failing to even ignite the gas at all. I'd presumed it was a faulty thermocouple, but on reading the manual, it seems this boiler has an electrode based sensor.

So, we called in a plumber who diagnosed a faulty gas valve (no gas coming through into the burner), which he had to order in (fair enough) The replacement valve has been fitted but the problem persists. The plumber is now saying it could be a PCB fault, which again I guess it could be. Either that or the new valve is duff. The problem is, if it does turn out to be the PCB and the new valve isn't required, he can't return it as it's been fitted and he's going to charge us for it, and then there'll be another charge for the PCB which he's said again, if that doesn't sort it, he can't return it and we'll be charged and so on. The problem is this method of "throw bits at it and hope it works" is going to end up costing us a fortune. I don't (and won't!) end up with a boiler full of new bits that doesn't work. I'm going to have a chat with him when he comes back, but how would you guys go about this? Also, any ideas as to the actual fault? I know these aren't the most reliable boilers, but it's been trouble free for 8 years up to now.

Thanks

 

[Biggles..]

You've employed a parts changer.
He should have been able to correctly identify what the fault was.
Did he use a multimeter to prove the valve was actually operating with the correct voltages from the pcb????

Should be the engineers loss if he's misdiagnosed the fault!

 

[Dan Robinson]

Indeed. Although, there are problems that can be a bugger to find, a decent engineer wouldn't penalise the customer by chucking parts at it without reason.

Especially a ****box like that

 

[45yearsagasman]

Tell your man to shove the pcb where the sun don't shine and call BG on a fixed price repair. You should pay nothing for his incompetency.

 

[Agile]

You engaged the engineer to come and diagnose the fault.

You did not ask him to change a lot of parts on spec at YOUR cost.

In spite of what others here are saying these are perfectly reasonable boilers and quite repairable. I have probably repaired about 1000 of them.

Based on what you have said about the symptoms, I am not so sure that its a PCB either.

There are some basic tests that an engineer should do before coming to any conclusion what the fault is.

In my view you should tell him you are not happy with his parts changing methods and ask him to replace the Gas valve with the original and then let him go without being paid for anything.

I would never charge for parts not required to fix a fault. But then I spend a lot of time initially to ensure I diagnose the fault correctly the first time.

Tony

 

[JBR]

I see you're in the same area as I am. We have a maintenance and repair contract with this company:
http://www.boilerrepair.net/
which I can recommend. Why not give them a call.

(Mods: if you see this as some form of advertising, please accept my apologies and delete the post.)

 

[bernardgreen]

In my experience the most common PCB fault is due to poor design of the cable sockets on the PCB resulting in failure of the solder joints of the connector pins. Over sized holes in the PCB means the all the vibration in the cable is absorbed by the solder in the joint which eventually fails.

At least one boiler manufacturer finally realised this and told his PCB manufacturer to improve the design ( pins fitting tightly into the PCB ) and to include additional cable restraints to absorb vibrations in a clamp and not at the connector. In at least one boiler the cables are now soldered to the PCB without the use of a connector. This means the PCB comes with the wiring loom attached and the PCB inside a "protective" case.

 

[Dan Robinson]

At least one boiler manufacturer finally realised this and told his PCB manufacturer to improve the design

Shame about the rest of the boiler though

 

[scott1980]

Thanks for the replies gents.

The parts changer has been back today to collect his new gas valve and been politely told to foxtrot oscar. We've got a gas engineer coming tomorrow who was recommended to us by another ex gas engineer, so hopefully, we'll get it sorted soon.

Cheers

 

[Agile]

Don't forget to tell us what the fault was!

Tony

 

[scott1980]

We got this sorted last week. The new plumber initially thought it was a faulty gas valve, but after some testing, it was the PCB. Turns out that the board was only switching the gas valve on for a split second, even with a blow torch on the flame sensor. He tested the sensor and valve seperately, ordered and fitted a replacement board, and we've been working ever since

Thanks again for the advice.