Ideal Independant C30 - L2 Ignition Lockout

[amzy]

I am GSR just waiting for my approval for the combustion chamber forum before I can make any posts.

Companys AA Heating & Plumbing UK based in walsall, west midlands

But I need some serious advice folks, literally pulling my hair out on this one.

Been GSR for just under a year and been doing pretty well with the fault finding on boilers, well that's what I thought, until I come across this one.

Followed the MI still getting L2.

Ideals are common for the condensing getting blocked I'm aware.

This is what i've done with no joy following the MI.

1)Cannot get u-gauge onto gas inlet from the gas tap on the bottom of boiler, they've decided to build a cupboard round the boiler, but the boiler has been working fine for over 3 years so i thought no chance pipework is the problem, did a working at the meter 20.5 mbar with cooker running, with boiler going through it's ignition sequence you see the u-gauge move up and down, so I thought gas valve is okay.

2) Checked ignition electrode, continuity fine and sparking okay.

3) Checked the flame ionisation, continuity fine down to the pcb.

4) Flushed the heat exchanger by pouring water down it, abit of grit in there nothing major and cleaned the condensing trap.

5) Gas valve okay 220vdc on plug, 4.1kohms on valve using multimeter, (according to MI fine).

6) Replaced gas valve still same problem.

7) I put LDF on the top of the gas valve and when the pcb sends power to gas valve, the bubble seems to pop slowly not rapidly, I would of thought this ignition attempt the gas valve would open fully and let abit of gas onto the burner and the ldf bubble would pop rapidly, but never checked a gas valve this way before.

8) Removing the condensing trap, water is dripping from the heat exchanger outlet that connects to trap slowly, where's this water coming from when boiler is not on, the customer has advised me he had to re-pressurise the system twice a day, is there a hairline crack in the heat exchanger? couldn't see anything when I was pouring water down it and also would this really stop the boiler from not igniting?

Any help would be appreciated.

 

[shambolic]

What's the micro amp reading on the detection probe when trying to light?
It will be the detection probe dirty as these need cleaned on every service. I would replace it.
Ps you MUST take an inlet gas working pressure any time you open cover. So I would be getting panelling moved.

 

[shambolic]

Ps yer heat exchanger is gubbed.

 

[amzy]

Thanks for the reply,

Thought the Heat exchanger was kaput, will drain the boiler down see if it stops dripping and confirm before I get carried away with my assumption.

The detection probe was dirty as you mentioned, I cleaned the probe and continuity was okay all the way down to pcb.

However you can't hear combustion taking place as you normally can and the heat exchanger doesn't get warm at all, indicating the gas isn't being ignited however there's no inspection glass to confirm this.

The ignition electrode is sparking fine, I physically held the thing in my hand and sparking good at the tip of electrode.

I haven't checked the reading on the detection probe, will check and let you know.

I was going to get a gas inlet once everything was working to ensure the boiler was working correctly, I was to determined to get the poxy thing up and running first tho. you can't even get a gas inlet from the gas valve because the test point is hidden behind the casing.

 

[shambolic]

The test point is hidden to stop Folk taking a reading and trying to adjust the gas valve.
You should get 5 micro amps on detection when lit. If it's not lighting it could be poor spark generator not lighting the gas.

 

[Agile]

Regardless, if not lighting then no detection current.

Is the test point really intentionally hidden or just poor design?

Needs a new main HEX and that means its beyond economical repair in the private market.

Tony

 

[shambolic]

Regardless, if not lighting then no detection current.

Is the test point really intentionally hidden or just poor design?

Needs a new main HEX and that means its beyond economical repair in the private market.

Tony

Tony be quiet eh! It's not beyond economical repair as hex is under an hour to change and a couple of hundred to buy.
And yes the test point is intentionally hidden which has been said many a time. The governer and test points are put behind a plate to stop you adjusting it.
He said it wasn't lighting or wasn't rectifying within 8 seconds?

 

[amzy]

Yeah the test point is intentionally hidden behind a plate, but any GSR person should know not to mess with the governor unless they know what there doing under advice from the MI.

I doubt it's igniting anything but I will check the microamp readings.

Think i'm going to change the detection probe and ignition probe see if it works, if all else fails a phone call to Ideal.

Really done my head in this one has.

 

[amzy]

So I checked the micro-amps on the sensing electrode nothing there.


Then I changed the ignition probe and flame sensing electrode checked height to the top of burner was accordingly with the MI, still the same problem as I thought.

got my u-gauge onto the gas inlet eventually and all okay 19 mbar when in ignition sequence.

Spoke to Ideal and she went through everything as per the fault finding book and said it could be a air/gas ratio problem, however if the gas valve has been replaced how could this be the problem she weren't much help and wouldn't advise on any other possible solution.

So I decided to adjust the amount of air onto the burner by holding my fingers on the air port where the gas and air mix before the fan blows it into the chamber, boiler fired up confirmed by with the blue neon on the front display as-well but with a rumbling noise and then F2 error (flame lose).

I put insulation tape over the air intake and left a 10mm gap, boiler fired up and went onto high rate, removed the insulation tape and boiler stayed ignited left it running for 10 minute's now every time I turn the boiler on without adjusting the air it fires up but with a rumbling noise then stays ignited and the rumbling noise stops.

Do you think the fan is not pushing the mixture into the chamber correctly?
I have checked/cleaned the injector and fan assembly still the same thing, Just shocked it's decided to start working after I did this complete madness.

p.s please move this thread onto the combustion chamber forum if you feel it should be there.