Ferroli 701 fan/ PCB/ problems...

[pelleeds1980]

Hi guys first post on this site. I have a Ferroli 701 combi boiler which ran fine until fairly recently - I'd taken 2 of my 5 rads off for decorating but since putting back on I have had a problem with the boiler.

Have had a CORGI registered mate of a mate round - the fan doesnt seem to be pulling through correctly and we have noticed a scorched area of the circuit board near point 13 where there are 2 resistors running vertically. He is saying that Ferroli isnt his forte so isnt really coming up with a solution.

He can get it to fire up correctly by blowing through one pipe or sucking out of the other (there is a Red pipe and a clear pipe - one attaches to the Venturi at the top and the other I think is the Modulating Balance tube) to simulate pressure in the system but when you reconnect this to the system the flame will go out which I assume means that the system isnt maintaining its pressure correctly

Does anyone know if this will be a PCB problem or if something else is causing this such as the fan?

Thanks if anyone can help,

Pete

 

[Rob]

Either a faulty air pressure switch (what the tubes attach to) or venturi needs cleaning.

Does the fan run at good speed?

 

[chrishutt]

Apparently the scorching of the board around the resistors is normal since the resistors are designed to run hot. A common reason for boards failing is burning of relay contacts - How do these look?

 

[pelleeds1980]

Hi thanks for the prompt response - we dont think its the air pressure switch that was his first thought and he has tested with a new one and didnt have any effect. He's had a poke around the venturi but cant seem to find anything amiss there but i dont know if hes cleaned it out fully.

He's suggesting replacing the PCB which I know is expensive hence why Im on here before I hameorrhage more cash.
Just checked the relays not sure what I would see if they werent working but they dont look knackered.

Fan speed might be something to do with it as the fan seems to run at just one speed theres no sense of it doing the low and hight speed as I think these should do. Weve checked the jumpers and nothing amiss there.

I dont want him to replace the PCB and find thats not it as I undertsand the cost implications.

DO you think it could be the fan itself or something on the board which controls the fan or neither of these? Not had heating or hot water all week thank god ive got an electric shower...

 

[Rob]

I cant understand why this is so difficult.

From you OP you say fan runs, yes? And blowing into the APS makes is fire up?

 

[chrishutt]

You can download the manual from the Ferroli site. It has a fault finding section which should help determine if the board is faulty. The neon lights on the board allow a preliminary fault finding check.

The fan runs at low speed at all times except when there is a call for heat when it should go to high speed. Sounds like yours isn't going to high speed.

 

[pelleeds1980]

Rob thats correct, thats right yes - thing is weve changed the air pressure switch and its the same story. If you blow into the tube and kink the tube (ie to retain pressure) the system works fine. If you connect it back to the system thats when the flame will go out.....

WE checked the LEDs and the right ones were on when we checked other day I think hes clutching at straws - hes seen the scorched marks and assumes the PCB is done in but I know they are about 200 quid so I dont want to proceed as he doesnt know the root cause

Can you give me any advice on what to do try to confirm my suspicions

 

[pelleeds1980]

Chris - there is no discernible sound difference on the fan in normal or firing up (i,e when we have blown into the tube) operation - does that mean a fan problem or the thing that controls it problem? I see there is a jumper in the manual we have checked that but dont know what to look out for really.

 

[Rob]

yes...clean the venturi!

 

[pelleeds1980]

Whats the best way of doing this properly please? By the way I am grateful for you two and the prompt responses

 

[pelleeds1980]

Ok so answering my own problem here but LED 5 (Red) is showing as Red when I try to get DHW so I am assuming this is a PCB fault as in the manual it says: waiting time, replace PCB.

 

[chrishutt]

I had exactly the same thing (red LED 5 on with test A) on an Optima 700 (essentially the same boiler) this morning! On the basis that it looked like it might be the PCB that needed replacing (@£165) the client decided to go for a new boiler, so I didn't confirm that it was the PCB (the middle (no.2) relay looked a bit burnt. I didn't find the wording of the fault finding guide very clear.

 

[Agile]

The PCB identifies a call for heat and speeds up the fan, the APS activates and the boiler can fire up.

Your PCB seems faulty as its not running the fan at full speed.

As long as its not for too long, you could get what you want by having the missus blow down your tube and then see if she fires up.

Tony

 

[pelleeds1980]

Cheers lads - the missus blowing down my tube tends to make everything better!- have given mate the go ahead to replace PCB so will let you know if that sorts it. Was thinking of replacing boiler anyway but given timescale and temperature ill have to do this so got my fingers crossed it does the trick!

Appreciate everyones helpful responses will be in touch witha follow up.

Pete

 

[pelleeds1980]

PCB replaced and everything singing as expected - cheers everyone for your time and comments