Biasi Riva Compact M90e.24s - Not firing Up

[DaveyBilston]

Hey, This is my First post and im affraid its similar to others regarding the Biasi Riva Compact M90e.24s

when the boiler trys to start you hear the fan start then just a clunk without it firing up, I've read the similar post to this and have tried all its suggests,

Although the fan was kicking in i tested its Electrical Resistance and thats fines,

I tested the Resistance's on the Air Pressure Swich - the Com-N.O and the Com-N.C. were both fine so the Pressure Switch hasn't gone, i checked the loop to see it was picking up a current and thats fine, however i will go and buy some new connectors and some cleaner tomorow as this may be a cause but as its sunday night cant go ne where,

I haven't checked the Venturi Device yet as i dont have a Diiferential Pressure gauge to check this but may get one to check if there not pricey and if you guys think it would help,

It did have the flue replaced and a service in june, ive tried to see if there are any blockages in the flue and couldnt see anything,

the only other thing the manual says to check is the Full sequence Device, which im going to have a look at now if i can make heads or teail of it,

any advice would be great as its been off a few days and had to buy electric heaters now for the kids bedrooms,Luckily we've been away with friends for a few days,

Regards

Dave

 

[transam]

does the boiler go to ign' lock out ?

 

[DaveyBilston]

No, just keeps clicking away

 

[transam]

When the fan operates there should be 230 V's on the aps between C ,& N.C , if my memory serves me correct this would be the the blk wire e.g C is common neutral (blue) blk wire is open or fan proving ., this must make in order for the ign sequence to continue . incidentally the removal of the combustion chamber is something that I would not have advised you to do!
than if this proves spark ign will occur , are there 2 caps on top of the boiler , are they in place & sealing.

 

[Agile]

You should not have opened the combustion chamber!

However, you can do the measurements on the APS connector on the PCB.

You have not mentioned if you are using a twin PCB model. I will assume thats the case and so the APS has three connections.

The first thing any boiler engineer would do would be to put the boiler into diagnostic mode and see what the boiler thinks is happening.

If you look for some of my previous posts you will see how to put it permanently into diagnostic mode and then drill holes in the front so all the LEDs can be seen from the front.

Tony

 

[confused7angry]

You should not have opened the combustion chamber!

However, you can do the measurements on the APS connector on the PCB.

You have not mentioned if you are using a twin PCB model. I will assume thats the case and so the APS has three connections.

The first thing any boiler engineer would do would be to put the boiler into diagnostic mode and see what the boiler thinks is happening.

If you look for some of my previous posts you will see how to put it permanently into diagnostic mode and then drill holes in the front so all the LEDs can be seen from the front.

Tony

Hello to gain access to the thermosat does this entail removing any of the combustion chamber covers? If so I`ll need a qualified engineer to complete this?

 

[Agile]

Modern boilers dont have "thermostats".

They use electronic temperature sensors which are read by the PCB.

Both sensons on this model are in the lower section BELOW the combustion chamber.

So a DIYer can test and if required change the sensors.

Tony