Icos system M3080 won't light

[jimbo.911]

HI there,

Our boiler has just decided to go on the blink, bt with an ideal should expect this, having had 2 pcb's in 5 years (one after only 1 month of having it!). Its showing LF alternate flashing.

I have cleaned out the condensate trap, refilled and refitted. I have also earthed out the ignition electrode and that fires up whenever the cycle increases the fan speed during its 3 light up attempts. I have also removed the white pipe on the gas valve and found it dry.

After I reset it displays a "3" on the control and runs through its cycle before going to the fault code. Any advice would be gratefully received.

All the best

Jamie

 

[gas4you]

Have you removed the sump door and cleaned this out, or just the condensate trap?

Try cleaning or replacing the rectification electrode.

Have you checked the gas valve is opening when asked to?

3 is just the 'identity' number of the boiler that the pcb thinks it is connected to.

 

[jimbo.911]

Thanks for the quick reply.

I only removed the trap and gave this a wash through. How would I go about washing the sump out? Is the rectification electrode also known as the detection electrode?

There is various clicks etc coming from the region of the pcb board etc. I put a circuit tester on it and it read a peak 220 volts across the blue and the black wires on the plug before dropping back to around 70 to 80 volts.

I'm competent when it comes to the taking to bits and putting back together but have no intention of touching the gas side of things, fully recognising the importance of CORGI.

 

[gas4you]

I only removed the trap and gave this a wash through. How would I go about washing the sump out?

With the trap off remove the 3 screws at the base of the HE and look inside with a torch, especially to the right hand side where the flue joins at the bottom. Clean out withe a good wire brush and hoover.

Is the rectification electrode also known as the detection electrode?

Yes, my mistake

I'm competent when it comes to the taking to bits and putting back together but have no intention of touching the gas side of things, fully recognising the importance of CORGI.

The above has nothing to do with gas carrying parts, but as you rightly say, leave the gas valve check to an RGI

 

[jimbo.911]

Thyanks for the info.

I've given it a good clean out, there was not a lot in there, cleaned the ignition electrode and the flame detection electrode.

Seeing as it seems to run through the cycle all ok, there is a spark and the voltages to the valve seem in he region of the expected 200V, would this point to it being the gas valve?

Thanks again for all the help on this one.

Jamie

 

[gas4you]

Whilst cleaning the ignition electrode, did you notice if both bits of metal were still straight or had the outer one 'bent' up or down away from the shorter one?

You could check continuity between the detection electrode and the connector that goes into the pcb case.

 

[jimbo.911]

Dave,

I gave them both a good clean. The continuity is all ok on the detection side and I reset the gap to three mm for the igntion. I earthed it out further down the electrode and there is a good healthy spark across the tips.

I let it run through the three ignition attempts whilst "sniffing" the flue there was no smell of gas at all, unlike the odd whiff you get from time to time.

Apart from the neighbours now thinking I have totally lost it, would I be right to think this points to the gas valve, what with the volage to it etc etc.
?

Your advice is very much appreciatted

Jamie

 

[gas4you]

It certainly appears to be pointing to the gas valve, but without being there myself and testing it I would be reluctant to jump in and say it needs replacing.

As a silly side point, I assume that the gas is on at the meter and the gas cock under the boiler is open fully?

 

[snb]

You can remove the connector on the detection electrode and start the boiler.

If the boiler lights ok then run for a minute and then reconnect. if it runs ok then it was purely moisture on it. If not then it is faulty.

 

[gas4you]

You can remove the connector on the detection electrode and start the boiler.

If the boiler lights ok then run for a minute and then reconnect. if it runs ok then it was purely moisture on it. If not then it is faulty.

Sh*t I forgot that one even though I use it when they don't fire up first time after a service

 

[corgiman]

strictly speaking Dave isnt removing the condensate trap and opening the sump on this boiler breaking a seal on the flue pipe ergo a RGI job?

 

[jimbo.911]

Guys

I tried removing the detection lead plug at the PCB connector, turned it on and it flicked straight to an alternating H & E which is a faulty PCB code.

Reconnected it and it through the usuall 3 cycles of trying to light before coming up with the L/F fault once more, still no joy.

Any further advice, including the usuall ideal "skip" solution all welcome.

All the best

Jamie

 

[corgiman]

probably a clagged up heat exchanger.

 

[jimbo.911]

Thanks for a further line of attack, would this lead to me not smelling any unburnt gas in the flue exhaust after its attempts to light?

There wasnt a lot of crap in the bottom of the boiler, probably about a tea cup full at the most and absolutely no moisture, totally bone dry.

I can't work out if the clicks are coming from the pcb relays? or the solenoid at the rear clicking open?

Oh well best keep the socks on in bed tonight

Jamie

 

[snb]

a tea cup of carp in the sump is a lot. normaly only get a couple of tea spoons at most on a yearly service.

Best advise is call out someone to give it a thorough check as if it has been serviced yearly it hasn't been done very well!!