Ferroli 77FF Poular - Pilot not re-igniting

[ozbodd]

Can anyone assist please?

Our Combi has gone cold and I cannot get the igniter to spark. It is a gas pilot Ferroli 77FF Poular.

I have checked the fuses
The PCB has a green LED illuminated
I have manually activated the air pressure switch.
There is >1bar pressure in the system

I am an electrician with refrigeration and airconditioning background but have no manual on this and I am unable to work out where to check for other failures.

The pilot went off yesterday and I started it straight away, today though it has gone again but refuses to spark.

Thanks in advance
Steve

PS if anyone has a manual (pdf) that would be greatly appreciated.

 

[weargas]

The white pilot button is attached to a grey pilot button. This button is held in place by a shroud with 1 pozi screw. Undo it and make sure the grey button still has the tag attached (it will be obvious). The tag presses the ignition microswitch but they have a tendancy to snap. You can also test continuity across this switch. If you're getting continuity test for ac voltage on the spark generator. neither of these come into play until the aps is made. I have all Ferroli literature in pdf, if you want to mail me I'll mail you what you need (users inst, installation inst, exploded diagrams and part #'s)

 

[ozbodd]

What can I say!!! Amazing service ...

I will go and try that now and see. One question though, when checking the igniter voltage do I need to activate the air pressure switch (vacuum)? Also do I test from probe to earth?

 

[ozbodd]

aps=air pressure switch

The actuator is fine, the Micro Switch has continuity. Where do I check for voltage on the spark generator (Is there terminals on the PCB?)

There are two covers you can remove - The white main cover and the internal pressure cover. Does the unit fucntion with the white cover off?

BTW I would very much like the manuals if you do not mind? [email protected]

 

[ozbodd]

Just a couple of other things I have just checked.

The aps has NC/NO and is OK though only carries 5V?

I presume the spark generator is the brown unit on the LHS of the circuit box, I metered the Brown/Blue and saw no changes when the micro switch was activated and the aps activated.

any further ideas weargas?

 

[weargas]

is there any signs of burning on the right hand side of relay 4 on the pcb?

 

[ozbodd]

I have manually lit the pilot and when hot water was drawn the spark started on the pilot (I presume when the aps kicked in) It fired up and we had hot water - For 5 minutes - It shut down again?

I have tried again with manually lighting the pilot and I can get it going and the spark starts, but the main burner wont start even when drawing hot water this time.

It appears that when the unit is idle the aps may be deactivating as I can only get the spark when the water is drawn and the fan ramps up a gear.

Is this likely to be a heat sensor somewhere?

 

[weargas]

Is this likely to be a heat sensor somewhere?

no.


underneath the transformer fitted to the pcb is a folded up piece of paper. It's a very good fault finding guide for that boiler. give it a look.

 

[ozbodd]

Cheers

Something is preventing the gas to the main boiler, I don't understand why I have spark, pilot and hot water running but no burner??

I have not received the pdf manuals not sure if you have got around to posting them yet - I posted my email above.

Thanks for the help weargas

 

[ozbodd]

FYI

I have got my hands on a manual and been through the flow charts and it appears the Operator Gas Valve is faulty - I am going to try and get the operator for the Honeywell valve on Monday to see if that is correct.

 

[weargas]

If you've had it fired up then the chances are your operator is ok. check for voltage at the operator before spending hard earned. it's a 24v dc operator on your boiler. your first post indicated a pilot problem, is the pilot lit but the main burner won't fire? The operator has nothing at all to do with the pilot so it's become a little confusing. perhaps i've misunderstood the things you've described.

I've looked through my ferroli pdf's and all i have for the 77ff pop is exploded diagrams and parts lists, how red faced am I?

 

[ozbodd]

It was the pilot to begin with but when I manually lit the pilot and made the aps the igniter began working. That first time the burner also kicked in and we had hot water for 5-10 minutes. Now everthing is OK electrically except the burner wont ignite.

I found a manual with fault finding flow charts

Fan running idle - Yes
Pilot can be lit when hot water running - Yes (Now)
Main burner ignites - No
24 VAC on 60-61 PCB - Yes
24 VAC on Gas Operator Valve solenoid- Yes (I can hear the solenoid click if I disconnect 1 lead)
Fault = Replace Operator Gas Valve.

I believe the problem is with the mechanics of the gas valve or the armature in the soleniod is broken. I have commissioned a mechanic to replace the valve Monday night so we will see ...

BTW - I have Tech Information/Installation and Service Instruction manual - I can get the flow charts and electrical diagrams scanned and send it your way if you wish?

 

[weargas]

The fact that the solenoid is clicking is usually a sign that it's ok, not always of course, you may be right. Bear in mind that after you depress the pilot button to light the pilot it has to come out far enough to allow the main gas through. If the pilot button is slightly sticking in it won't allow full gas. The fact that this whole thing started with a failed pilot makes it likely. Check it's coming fully out before replacing the solenoid. Give it a bit of a wiggle whilst pulling it towards you. Not too hard or you'll pull the white button off the gray button. Don't twist it either or it'll fail the pilot.

BTW - I have Tech Information/Installation and Service Instruction manual - I can get the flow charts and electrical diagrams scanned and send it your way if you wish?

Very kind of you but I have it all in my head.

 

[ozbodd]

Check it's coming fully out before replacing the solenoid. Give it a bit of a wiggle whilst pulling it towards you.

I see where you are coming from. I just took the knobs off and worked the valve a bit and tried it again. With the unit calling for CH I still can only get the the pilot to ignite, once I release the valve it goes out and no burner.

As for your question earlier about relay 4 I can only see three relays and the only one that appears to have charring (As if any should!!) is the fan relay which is working fine.

 

[weargas]

so you're saying that you can light the pilot but as soon as you take your finger off the button the pilot light goes out?