Ferroli Modena 102

[FlowGas]

Hi everyone,

I'll be attempting to restore the CH for a customer tomorrow. They have DHW, but no central heating. After reading the MI I'm assuming that its the CH sensor as they don't have a room stat. Following the MI's, I'll be isolating the electricity and water, disconnect connections, drain all CH? or simply just the at the boiler?. and replace sensor.

I'm I going about this in the right manner,(fault finding process). Once the sensor has been replaced, if the CH still doesn't work what other potential fault could it be.

Your advice and guidance will be much appreciated. Please do share your experience's with this particular boiler

 

[villa_tom]

I'd get there and have a look before getting a sensor. It could be a million things before you replace the sensor.

 

[lame plumber]

all depends what you find on examining it, or you will soon have lots of gear on ebay

 

[Deleted member 44451]

i had the same prob with a neighbors boiler, i just took the lead off the sensor and put it on and of a few times and hey presto! that was a year ago and heard nowt since

 

[Deleted member 44451]

it was a modena btw

 

[Billy Bob Bob]

pump or roomstat or timeclock failed start by looking for 240v at the pump if you find it pump failed,if you dont find it bypass the room stat if that dont work then the clock,it wont be thermistors as its getting dhw and the ferroli 102 pcb looks at the primary(ch)thermistor before it allows dhw operation come back if what i have said does not fix it.BTW chaps pumps not needed for dhw operation on this boiler its a twin pass heat exchanger

 

[FlowGas]

Guys thank you for the advice,need a bit more help now. :sad: I drained down the system, opened up the pump, a little bit of water came out and I think it got onto the PCB somehow, as there was a spark then a not so lovely burning smell afterward once I gave the boiler power. An epic failure on my part. Anyways, I ordered the part yesterday, picking it up this morning. Any advice on fitting the PCB board? Don't really want to blow another one.

 

[moogwai]

Guys thank you for the advice,need a bit more help now. :sad: I drained down the system, opened up the pump, a little bit of water came out and I think it got onto the PCB somehow, as there was a spark then a not so lovely burning smell afterward once I gave the boiler power. An epic failure on my part. Anyways, I ordered the part yesterday, picking it up this morning. Any advice on fitting the PCB board? Don't really want to blow another one.

A spark from where? Last time I had a burning smell from one of these the connecter on the pump lead to the pump had melted!

 

[FlowGas]

The spark came from the pcb board.

 

[FlowGas]

Just picked up the pcb board gents. Any advice or precautions I need to take that aren't stated in the MI's?

 

[dancinplumba]

Earth your self and or anti static strap. Don't touch board

 

[moogwai]

Turn off at spur, remove fuse and do your safe isolation tests.

 

[FlowGas]

We have power, now theirs a red light on the 2nd light, any ideas?

 

[FlowGas]

Fans gone :banghead:

 

[FlowGas]

Gents, there was a dodge connection sorted that out. Now the boiler fires up for hot water but cuts out after 5 or so seconds. every couple of resets, the pump runs also. I've changed the electrode, still no luck. This has been one long day. Some advice please. It goes to lockout once it goes out.

 

[R1CKY]

If it fires up WITHOUT ANY DEMAND it is likely to be a sensor at fault, they come in pairs and should both be changed.

Other common faults with these are the venturis in the fan, they go brittle and crumble away, this can also cause it to fire momentarily and cut out.

Some models, if not all, have potentiometers on the boards to control ignition, min and max gas rates for the gas valve, they should be factory set and have tamper evident markings on them, make sure it is not a returned board that someone has previously played with.

Aswell as the two wet sensors, there are two clip on sensors on the heat exchanger, one is an 88degree stat and the other a High limit stat rated at somewhere around 105 degrees IIRC. These rarely fail, but can cause issues.

From memory, if open the combustion cover slightly and it stays fired up, this indicates a venturi fault. But do not touch the venturi unless you have a replacement or you are 100% sure that is the fault, as 9 times out of 10 it will crumble in your hands!

 

[FlowGas]

Thanks for the reply, it fires up when there's a demand for dhw(open hw tap) then fires up, while its fired up it continues to make a ignition sound and then goes to lockout. The spark electrode I've changed, maybe the flame rectification?

I'll change the ch and dhw sensors. Do I have to drain the system again to change both sensors ? As there's still 1bar of pressure within the boiler.

 

[R1CKY]

Don't change the sensors just yet, it does sound more like a rectification fault. You did remember to plug the sensor probe back into the board?? It goes on to an earth tag on the bottom left of the board if I remember correctly.

 

[FlowGas]

 

[R1CKY]

All seems well there, check there is no moisture on any of the connecting plugs. I too have soaked a pcb on this boiler and it kept going to ignition lockout. Get a hairdryer on it.

 

[FlowGas]

will defo give that a go tomorrow morning. If that doesn't work, are there any other routes I could take?

 

[Billy Bob Bob]

double check the detection electrode to pcb connection it goes into that black block from memory its very easy to get a bad connection there

 

[moogwai]

Maybe also check burner jets and give them a clean as well as cleaning the burner.... Could be that there may not be enough gas getting to where the rectification probe is sited ( think this probe is at the back of the burner, might be wrong).

 

[FlowGas]

No luck guys.

 

[moogwai]

No luck guys.

Gas mans axe then.