"FIXED" Biasi 24S Ignition spark on; No flame,

[andy123456789012]

The lockout happens every time, perfectly replicatable. PRess the red button and it happens again and again and again.

I've looked at the service manual diagnostic flowchart. There are some things to check (with a multimeter) and some which I can't check as they are gas related.

I have noticed that the GAS IN pipe (the middle one of 5)has a yellow lever which is vertical whereas the COLD WATER IN pipe has a blue lever of which the long part is pointing 250 degrees.
Its clearly not in the right position (nearly off!) so what is best safe practice to TRY to free this blue lever?

I also noticed green scale above the lever valve so I presume there is a tiny bit of a leak unnoticed. Would this reduced water input due to the water in restriction, cause any lockout problems? My sense tells me it does not, but I thought I would ask so its clear straight away.

IT seems that the flowchart points to the gas side being a problem (gets to ignition spark stage but no gas to ignite..). All I can do is check with a meter any pcb circuits related to opening the gas valve. I have noticed a gas "modulating operator" on the leftmost side of the main circuit board. It states ~21volts in the manual.

I think this is the correct set of pins to check which I'll do tomorrow.

So, I'm just wondering if there are any tips floating around?

 

[transam]

Which biasi 24 s do u have , old style riva , is there a red ign pcb on the gas valve ???

 

[Agile]

You have the older 24S with three knobs.

The blue tap has probably got a damaged key and is not moving the shaft.

Its common for the blue tap to be adjusted to limit the flow to what the boiler can heat.

The ignition lockout is created by the red/black ignition PCB. There is little that you can do to identify the fault.

As its gas/combustion we are unable to give fault advice to DIYers and so the recommendation is to call a competent boiler engineer.

Tony

 

[andy123456789012]

Thanks, I lurked here for a while and I understand the gas concerns....and I am grateful for whatever advice is given.

Agile is correct - 3 knob version of 24S

I checked the pin sets on the mainboard and everything reads fine with a voltmeter except for the leftmost pair on the circuit board reading 9.76VDC and not 21DC, which are called "Modulating Operator"

I made sure to keep the reading going during and after pushing the lockout reset button until it locked out again (about 10 seconds - NO GAS). Same reading consistently.

This seems to indicate a lack of the correct voltage going to the on/off operator of the gas valve. Does this make sense?


[/u]

 

[transam]

Yes ????


I need to tread a careful path here , assume you have a service manual ?
page 25 deal's with resistance on a particular component , ??? checking this would be electrical ????

 

[andy123456789012]

Lol, dont mention that component in the restricted "area"
All I need to know is whether the lack of 21VDC is indicative of a main board fail and whether I should look for a new one.

 

[Agile]

Its totally irrelevant to you what the voltage to the modulating coil is and what you have measured is fine!

You have not mentioned if you can see sparking through the viewing window.

If you see sparking then almost certainly the gas valve is failed. Its either stuck or the solenoid is open circuit. There are two coils. The book gives you the resistances. Within 10% is adequate.

You can measure the gas valve coil resistance, you can measure the applied voltage IF the resistances are correct but that is raw DC and the reading will fluctuate widely according to the type of meter you use.

At the end of the day you will need a reg gas engineer who is competent. If he says Biasi boilers are crap and sucks through his teeth then he is not competent.

These are totally repairable boilers for anyone who understands how boiler work!

We dont give advice on DIY gas work here. Nothing I have said above contravenes that ruling.

Tony

 

[transam]

According to my imfo the coil resistance should be approx 117 to 125 ohms , the modo reg max voltage 15 dc minimumn 9 vdc min gas

on off operator's on whatsit , top on off 1260 , bottom on off 2980 / 3000 , would suggest that this is problem ??? check resistance' s on whatsit

Could be in for a rollicking here ???????????

 

[andy123456789012]

Thanks again..

Agile:
I did write this in my first post:

(gets to ignition spark stage but no gas to ignite..)


I shall check the suggested items with my £20 maplins meter, with acknowledgement that it may not be totally accurate.

As for the competent Gas engineer, I hope my neighbour, who has "contacts", will be forthcoming and not know any air-teeth-suckers. Actually, it should make sense to contact biasi and find their local authorised engineers.

Regarding contravention of gas advice, I'm not aware that I made any comment to suggest I was after DIYGAS advice, but I did make a comment directed at transam. Maybe some confusion because of the timeline?

________
Transam, I was looking at those thingamajigTM measurements in the service manual. I might check the 1260-3000R as well if there is any point. Rest assured, I have no intention of messing around with the gas side of things. When there is nothing left to check, that's it.

 

[Agile]

Calling your local Biasi service agent would be a good idea.

You can measure the gas valve solenoid resistances with the ignition pcb box removed. If open circuit that would prove the valve is failed but it could also just be stuck.

Tony

 

[andy123456789012]

You can measure the gas valve solenoid resistances with the ignition pcb box removed

The biasi service manual stated:
CHECK THE MODULATOR OPERATING COIL
1) Disconnect 1 of the two (spade) connectors of the modulating coil.
2) Check the resistance of the coil = should be about 125R.

I must be missing something because from my understanding of meters, to check resistance requires two points for measurement..
Anyway, whether its correct or not I removed the other spade connector and checked both ways - Reading was 114R


Then I removed the full sequence ignition device which left me with a set of 5 vertically stacked pins.

I checked the top 2 Target =1260R Actual = zeroR
bottom 2 Target 2980-3000R Actual 2136R

 

[Gasguru]

You need the gas valve replaced IF your diagnosis is correct by someone gas-safe registered. The gas valve is NOT plug and play...it needs setting up etc

 

[andy123456789012]

Relax helpful GasSafe advisors. I have no intention of messing with the gas. I run a mile when I smell gas from the cooker, before its ignited.

Anyway, I'm wondering if its time for the 9 year old boiler to be replaced to avoid any issues of lifetime scale build up, aging, worn parts, etc etc.

Quality of installation and then price are my biggest worries.

I'll decide in a few months before the winter period creeps in.

 

[transam]

So we won't be seeing a report of an explosion in Essex on the evening new's than ???? Incidentally if you were to relace your boiler with another Biasi condenser , the one with the stainless steel 2nd heat exc which B&Q still stock , it would be almost an exact swap , wouldn't even have to swap the mounting bracket , if the flue is currently side exit the hole ect would also line up , rear entry it won't !!! don't bother with there newer band B model , gone all plastic ally 2nd heat exc ' , also not the best of company's to deal with , but 20% on a wednesday if you no an oap ???

 

[andy123456789012]

I'm shocked, do people who are ultra unqualified mess with GAS fittings..... What a scary thought. Its not just if they are trying to save money....Its their life (obviously does not matter to themselves) their family, pets, the property, damage to surroundings, other people. Yes, I posted some boiler q's in another thread lol.

EDIT and the emergency services, the gas free flowing, or is there auto cut off somewhere, probably...

The family trauma etc etc