Biasi Boiler problems

[timex tim]

Hi all,

I have a problem on my Biasi GAIA savio 28s (manufactured in 1999).
Basically it stopped providing hot water out the taps when requested, the up shot is that I have to put the central heating on to get how water to flow from the taps.

I contacted a CORGI registered heating engineer, who took at look and said it was the diverter valve and a replacement part alone would cost (…….get ready) £387.00 plus VAT plus fitting! As well as 2 new flow switches (nothing wrong with them)

After I showing him the door, I had a look at some of the pages on this forum and carried out the following work myself.

Stripped down the diverter valve, cleaned and reassembled (works fine mechanically)
Checked the 2 diaphragm/membranes (bit flappy but not torn or punctured)
Checked the DHW filter.
Examined the main PCB and found there was an area that had signs of overheating (underneath the small heatsink at the bottom left hand side of the board)

Basically I have these questions

Is there anything else I should check for this symptom?
If the diverter valve works mechanically could there be anything else wrong with it?
Is a small amount of blackening usual on a the PCB?
Should I just change the board?
If so I’m getting contradictory part numbers, the manual says BG1015 108 and the stockests list the part as BI1045133 formally (1045104)

Any help would be greatfully appreciated.
Have a good week

 

[Dan Robinson]

Does the boiler fire when the tap is opened?

Is the 3-way valve functioning? Sorry, but I am not sure whether it is in hot water or central heting mode when at rest.

 

[gas4you]

Don't really know on this one, but a 'flappy' diaphragm is not the same as a nice 'tight' new one.

 

[bobthebender]

Don't really know on this one, but a 'flappy' diaphragm is not the same as a nice 'tight' new one.

This is a Biasi diaphragm that i changed and cost £9 delivered.
You can see the split.

 

[ChrisR]

Could just be a microswitch! You really need to do some diagnosing...

 

[Agile]

For a start see if the diverter pin is moving towards the DHW flow switch.

To follow see if the DHW flow switch brings the boiler on when manually activated.

There is no "small heat sink at the bottom left hand corner" !

You probably mean the heat sink on Q3 which is on the top left corner?

That controls the current taken by the modulating coil !

If the DHW diaphragm is not pushing the diverter then there might be a blockage in one of the bundy tubes.

Tony

 

[Rob]

Agree with ChrisR, all your doing is listing parts in the boiler and think you know what your talking about.

Just by saying 'ive checked this, ive checked that, nothing seems to be hanging off or snapped doesnt mean its working.

It needs diagnosing on site by someone who will be happy to explain the fault why its occured and obviously the cure.

Im not saying he was correct with his diagnoses but why 'show someone the door' because it wasnt the price you were hoping.

If it didnt work you needent pay him.

 

[Bahco]

Sympathy is with OP on this one.

£400+ is a scandalous price to have to pay for a repair

Try another engineer who has been recommended to you that will charge you a fair price

 

[bobthebender]

Sympathy is with OP on this one.

£400+ is a scandalous price to have to pay for a repair

Try another engineer who has been recommended to you that will charge you a fair price

It is when the boiler only cost that

 

[timex tim]

Thank you everybody who shared their knowledge and patience with my questions. The problem turned out to be a faulty (badly corroded) micro switch as ChrisR suggested. I did take a picture but I'm not too sure how to upload it.

I have one on order and I'll change the flappy diaphram whilst I'm at it.

To set the record straight the heating engineer who came and mis diagnosed the fault, wanted to charge £387 plus vat, excluding labour for a part that I can get for £90+vat on line (retail). I have no problem at all for paying for skills and craftsmanship but do take issue with this type of mark-up. He also said it might be the PCB as well and he could get one for around £900....the numpty!

Thanks once again guys

 

[Dan Robinson]

Thanks for clarifying Tim. He certainly sounded like a bit of a tool.

Remember a lot us do this for a living and whilst we keep things fairly neutral most of time; some comments do automatically get the defences up - if you see what I mean.

There's a FAQ on posting piccies - the more info the better the forum.

 

[Agile]

Tim, the switch will have failed as a result of a failed gland !

The gland will need to be replaced as well as the pin unless its very carefully cleaned with wire wool.

The gas valve would normally have to be removed to access the gland and that should be done by a competent person usually a CORGI.

One enterprising DIYer did manage to do it by removing the LH hydraulic block though.

I dont recommend replacing the diaphragm if its working fine as it can easily be replaced anytime in the future when it fails. It could end up with leaks you might not be able to manage.

Tony

 

[ChrisR]

Water from a leaky gland can get around a bit...

 

[Dan Robinson]

Christ almighty what abortion did you take that from?

 

[corgiman]

My professional opinion is that its F'''Ked

That will be 84 please (agile's diagnosis fee)