3 way fridge, flame goes out

[Willbiker]

Hi all

 

I have picked up an old 3 way fridge. 230v works fine, 12v also works fine as the rear element gets nice and hot. The gas side of things works ok except the flame will not stay alight. The fridge looks like it has an aftermarket control box and the wiring looks all chopped about.  Anyhow, I can light the fridge using the piezo igniter and can keep it lit by holding the button in. I hold for as long as 1 minute, enough time for the thermistor "I think that's what it's called" to heat up but the flame goes out when I release. I know that the thermistor is working correctly as if I blow the flame out while holding the ignite button in, i cannot relight it again with a lighter ( i have the burner out of the flue) so I know its cutting the gas as it should. 

 

So I think the issue is the gas solenoid. I thought these things took a 12v supply which keeps the gas flowing and when the supply is cut, the gas shuts off? Well this fridge appears to have a 230v supply to it. Is that correct?

 

Thanks

 

Will

Edited August 11, 2020 by Willbiker

[Willbiker]

I resolved this 5 minutes after posting! The thermister wasn't positioned far enough into the flame. After a reposition and a clean, its working.

 

[Jaydug]

2 hours ago, Willbiker said:

I resolved this 5 minutes after posting! The thermister wasn't positioned far enough into the flame. After a reposition and a clean, its working.

 

If it's the bulb that sits in the flame, that's the thermocouple.   The bulb heats up producing a current which holds open the gas valve.   Initially, you open the gas valve by pushing in the knob then the bulb heats up and produces the current to take over.   The thermocouple needs to produce around 25mv to work.   When mine was becoming unreliable last year, it was only producing 19mv - not enough to hold the gas valve open.

[Townie]

Just an aside. When using it on gas, the fridge needs to be quite level, otherwise the pilot light won't stay alight.

[James Donald]

Mine runs on gas when towing the van and has only ever gone out once to memory .

[WispMan]

In the UK it is a bit different as no naked flames are allowed at Service areas. 

We tend not to travel with the fridge on gas. 

[Fenester]

2 hours ago, James Donald said:

Mine runs on gas when towing the van and has only ever gone out once to memory .

IMHO :Towing with the gas fridge is not a good idea. In a accident with leaking fuel about it is not a good combination. Albeit the 12v supply is not great on efficiency, that is what it is for. Never leave fridge on gas on the car deck of a ferry either please.

Edited August 12, 2020 by Fenester
Grammar/Punctuation

[WispMan]

James is in New Zealand

[Fenester]

3 hours ago, WispMan said:

James is in New Zealand

Wherever; it is in my view not a good idea. I didn't want people on here thinking towing with a fridge on gas with a naked flame was normal practice.

[WispMan]

I agree so I hope James can explain how it is different in NZ

[Willbiker]

Thanks for the info. Maybe one of you guys can help me figure out how the igniter button is supposed to be configured. This dodgy looking control box has a button which pulls on a cable operating the gas bypass and piezo igniter. But how is the cable meant to connect into the mechanism.  Maybe its  missing parts. Anyone have an example picture or diagram? Cheers!

Edited August 13, 2020 by Willbiker

[Brecon]

I have never, ever, seen anything like that in any van I have worked on in over 20 years.

It may help to know what make of fridge it is, but I doubt very much if there is any information anywhere about it.

[Willbiker]

The fridge is a camping gaz internation and I think its a t618 model. But I'm sure this is an after market bodged up control unit. I may make a new one but I cant see where I can buy one of those push ignitor buttons which connects to a bicycle style  cable.

[WispMan]

You are altering a Gas powered device in an enclosed space where you and your family  sleep in a 22 year old van. 

You really should use a Gas Safe engineer as you are putting your lives at risk. 

[Jaydug]

13 hours ago, Willbiker said:

 But how is the cable meant to connect into the mechanism. 

 

Someone seems to be trying to make a simple device more complicated.    A piezo ignitor doesn't need to be connected to anything other than the gas burner pilot jet.   Neither does it need bicycle bowden cables.   As others have said - get an engineer to look at it for you.

[Brecon]

I have found an old UTube video of your fridge and the control box is the same as yours, so it is original.

However, there was no decent video footage of how it actually works and was not stripped down as you have, and it is in Italian !!  

 

 

At 22 years old I doubt very much if any spares are available and that is probably why you got hold of it.

 

Yu would be much better advised to obtain a more modern unit for which spares are available, as well as manuals.

Edited August 14, 2020 by Brecon

[James Donald]

Had a gas fridge in a 33ft boat for 14 yrs , used  to go day and night ,very rough or calm , worked perfectly and still here to tell the story? Do you think fridge makers would make and sell them if they considered them so dangerous? I do not run it when on our Interisland ferry but that's only a 3 hr trip . We don't stop at the huge big service areas in NZ as you people seem to do. They certainly have a safety cut of valve to stop any flow of gas once the flame goes out to.  Accident ! Well I'm not sure about that concern ! If that were the case , you'd never leave home ??

[DACS]

On 12/08/2020 at 10:53, Townie said:

Just an aside. When using it on gas, the fridge needs to be quite level, otherwise the pilot light won't stay alight.

This will apply equally in all three modes of operation, not just gas.  Each power source just provides heat to evaporate the ammonia.  The rest of the system needs to be reasonably level to function as some sections flow down a fairly gentle gradient.

25 minutes ago, James Donald said:

Had a gas fridge in a 33ft boat for 14 yrs , used  to go day and night ,very rough or calm , worked perfectly and still here to tell the story? Do you think fridge makers would make and sell them if they considered them so dangerous? I do not run it when on our Interisland ferry but that's only a 3 hr trip . We don't stop at the huge big service areas in NZ as you people seem to do. They certainly have a safety cut of valve to stop any flow of gas once the flame goes out to.  Accident ! Well I'm not sure about that concern ! If that were the case , you'd never leave home ??

The problem is not with the flame failure device but that the naked flame provides a source of ignition for spilt fuel etc..  I have experienced an explosion aboard a yacht with a petrol auxiliary engine.  Petrol leaked into the bilges and after a period of stiff sailing the fumes reached the fridge pilot light.  Similarly, a naked flame near petrol pumps at the roadside poses a serious risk.

[Ern]

9 minutes ago, DACS said:

This will apply equally in all three modes of operation, not just gas.  Each power source just provides heat to evaporate the ammonia.  The rest of the system needs to be reasonably level to function as some sections flow down a fairly gentle gradient.

The problem is not with the flame failure device but that the naked flame provides a source of ignition for spilt fuel etc..  I have experienced an explosion aboard a yacht with a petrol auxiliary engine.  Petrol leaked into the bilges and after a period of stiff sailing the fumes reached the fridge pilot light.  Similarly, a naked flame near petrol pumps at the roadside poses a serious risk.

You needed drop holes. You dont get the problem when youve got drop holes. Nice big ones!