Fridge - gas ignition problem

[jonohara1]

Hello

I had to take out my fridge it's a RM184 EGI from 1985 westy. The gas used to light very reliably, but now i can get no spark at the ignition.

I've tested the voltage of the braided wire/spark plug and it's getting about 9.5v to the end that sparks. But no spark. The image below shows what's there, does this look ok? Is there something missing (when i took it apart i found in the chamber what looked like then end of a small rivet, but thought nothing of it and threw it away!)



What's the other ceramic thingy the one connected to the metal tube? And are they close enough together for the spark to arc across?

Thanks in anticipation.

[lloydy]

you seem to be missing the actual pilot light, you should have a pilot tube[gas pipe]coming from the top of the fridge and joining onto the assembly in the photo, you have only got thermocouple an electrode. You can check if electrode sparks by holding a screwdriver close to it and seeing if it arcs [hold plastic handle on screwdriver!]
If your not to sure what your doing, you would be wise to get someone qualified to fit it for you. LPG a very dangerous gas not something to DIY really.
I'm a gas engineer, if you do fix it be doubly sure theres no leaks, good luck!

[jonohara1]

Thanks for your response. I've removed the pilot light. I'm just trying to get some spark. So i've got 9.5V going to the rightangle sparker, what does it arc to, the gas burner/pilot? Still no spark when the burner/pilot is reinserted.

[kevtherev]

it jumps to earth so you need to create a gap from the electrode to earth that it will jump successfully.

try a short wire that's grounded and offer it to the electrode

and yes it usually jumps to the burner

[jonohara1]

Thanks Kev

Can't get it to jump to a grounded wire. Do you think it might be a problem with the voltage is 9.5-10v too low?

[1664]

9.5v wouldn't wake a sleeping bacteria. A decent spark requires thousands of volts to jump the air gap (very low current though so it's not dangerous) and is instantaneous so you will not be able to measure it. Think of it as being a bit like static - when you touch a door handle etc you get a quick spark and a 'shock' but it's over before you know it. Where are you measuring the 9.5v between? The electode and the fridge body? Is that a permanant voltage regardless of whether you're trying to use the ignition or not? As I say you'll never measure the spark voltage (you wouldn't half feel it though......)

[jonohara1]

I've measured the voltage out of the black box on the top, where the braided wire/electrode is attached and at the electrode its self. So is it the gas switch (on the three way switch) which should trigger this spark? Any idea what order each step is in?

Cheers

jon

[lloydy]

check along the lead and see if its arcing elsewhere look where the lead joins the electrode, if you find anything, insulate it

[1664]

Problem here is I don't have a westie (thankfully ) and westies tend to do everything different to British conversions. I can only advise based on British but they shouldn't be too far removed......

Right, lets start by replacing the burner pipe as that is (probably) where the spark will be jumping to. Check you have a 12v supply to the 12v connections on the fridge and the polarity is correct. Trace the wires to the ignition switch and check for the voltage there. If you have 12v at both of these, and the ignition switch is working you should get a spark unless the electrode and burner pipe are not aligned properly, the gap is too wide or the spark might be jumping to some other metalwork or tracking across damp and not jumping to the burner. If the burner pipe or electrode are dirty or carboned up this can interfere with the spark too.

Do not be tempted to bend the electrode or burner pipe............

I'm off to the boozer now but I'll be back on later - see how you get on (I bluddy hate westies ) and watch your fingers!!

[jonohara1]

Thanks everyone so far. There is no spark anywhere along that braid covered wire although it's seen better days. I've a 12v battery correctly linked to the 12v connection to the fridge. I've measured 12v at the switch all fine. I've also measured 12v going into the black 'ignition' box and a steady 9.5-10v on the terminal on the black box where the braid covered wire connects. When it's all connected and the gas button pressed absolutely nothing happens no clicking no red ignition light - there is no voltage on the terminal from the black box which feeds the red light which normally lights when the ignition is working.

I've check all the earths are good. At a bit of a loss as what to do next!

Cheers Jon

[1664]

At a bit of a loss as what to do next!

running out of ideas here too. I have never actually ventured into the 'black box' - based on the old adage of 'don't fix what ain't broke'. Give me tomorrow to have a try of a few things with my fridge to compare with yours. There is a metal enclosure that surrounds the electrode/burner etc. Have you tried it with that back in place? I have a vague recollection that that made a difference when I had fridge problems back in '05 - that was a piezo ignition but worth a try.............

[jonohara1]

Question...What stops the ignition working when the fridge is lit. Is it the thermo couple? Could the thermo couple be faulty?

[jonohara1]

Answer...When there's a flame between the burner and the electrode there is less resistance than when there is just a gap (no flame). The ignitor can measure this and decide when to spark i.e when there is no flame. Probably then a faulty ignitor.

[Plasticman]

I had the same prob a bit ago, fitted a manual (kerchung kerchung) peizo button works everytime kerchung kerchung
Mike

[kevtherev]

Answer...When there's a flame between the burner and the electrode there is less resistance than when there is just a gap (no flame). The ignitor can measure this and decide when to spark i.e when there is no flame. Probably then a faulty ignitor.

process of elimination...

elementary my dear watson