Thetford oven doesn’t light

[cglittle]

Probably a basic repair, but what would cause the igniter in the oven not to work? Do I need a replacement part, or could it just be a loose wire?
Does oven need to come out to fix?

Grill lights fine, as does the hobs. Oven works when lit with a lighter, but there’s no igniter spark.

 

[audiorob]

If the other has appliances light from the ignition switch then you can ignore this suggestion - all mine light at the press of one switch - audible click repeats until lit - is operated from the caravan 12v supply and therefore only works when my master 12v is switched on.

 

[cglittle]

If the other has appliances light from the ignition switch then you can ignore this suggestion - all mine light at the press of one switch - audible click repeats until lit - is operated from the caravan 12v supply and therefore only works when my master 12v is switched on.

Yes, grill lights fine, and it’s all the same equipment. Just seems to be oven not sparking up.
12v supply is fine.

I’m going to remove oven from cabinet and have a look for a loose wire… if not that, I’ll order a new sparky thingy… (thermocouple?)

 

[Mr Plodd]

Good luck with that!

Ovens can be a nightmare to remove!

Personally I wouldn't even think of it, I would go out and buy one of those long lighters and use that for the odd occasion I wanted to light the oven.

 

[ProfJohnL]

Yes, grill lights fine, and it’s all the same equipment. Just seems to be oven not sparking up.
12v supply is fine.

I’m going to remove oven from cabinet and have a look for a loose wire… if not that, I’ll order a new sparky thingy… (thermocouple?)

Hello cglittle,

The thermocouple is not the ignitor. The thermocouple is parts of a safety system called a Flame Failure Device (FFD) system and if the flame goes out it
will automatically shut the gas flow off after a few seconds.

The ignition system will use another electrode made of ceramic tube with a length of wire sticking out of it. it is designed to sit about 3 to 5mm above the burner, and when the ignitor is activated , the energy will produce a high voltage spark that will jump from the probe across a port on the burner bar to ignite the gas/air mixture.

The flame should be an transparent blue colour of an even height along the length of the burner. Where the ignitor and the thermocouple probes touch the flame it might turn orange.

If the flame is a solid yellow or is producing soot it means the its not burning correctly. This might prevent it from lighting, and it certainly needs checking out. It might just need the burner cleaning, and instructions for this should be found in the users handbook.

Bear in mind this is a gas appliance with an open flame that burns inside the living space of the caravan. If its not burning correctly it will be producing Carbon Monoxide gas which is seriously harmful.

For the safety of you and your family, I strongly recommend you arrange to get the cooker serviced by a member of the Approved Workshop Scheme (AWS) who will know how to check the function and safety of the appliance.

Postscript. Mr Plod's suggestion of a gas lighter stick would be simple solution, provided the flame on the burner is blue, Low cost potion and pretty reliable

 

[cglittle]

We already use a lighter, but my wife wants it fixed so it’s working as it should.

no problems with gas or flame once lit.

is changing the igniter an easy job, or one that involves dismantling the oven

 

[Buckman]

We already use a lighter, but my wife wants it fixed so it’s working as it should.

no problems with gas or flame once lit.

is changing the igniter an easy job, or one that involves dismantling the oven

If you remove the oven you may need to disconnect the gas supply and then reconnect it at a later stage. It would be very advisable to have a gas qualified person do that reconnection as you do not want gas to be leaking out.

Also it may invalidate any insurance you may have on the caravan if you do the reconnection and you are not gas qualified. As said the majority of us would simply use a lighter. Cheap, safe and effective.

Why not have the repair done as part of the next service on the caravan?

 

[ProfJohnL]

We already use a lighter, but my wife wants it fixed so it’s working as it should.

no problems with gas or flame once lit.

is changing the igniter an easy job, or one that involves dismantling the oven

If the hob and grille are igniting correctly, it means the spark generator (ignitor) is working, so the problem is almost certainly the high tension lead to the ovens spark electrode, or the electrode that has developed a fault. It might have just become disconnected from the ignitor.

Because you have needed to ask about removing the cooker, I have to conclude you are not gas qualified, and as such the removal and repair really should be done by a competent fitter who has the necessary tools and knowledge to ensure the appliance is repaired and refitted and tested in accordance with the regulations.

 

[cglittle]

No… I’m not gas qualified. I’d hoped it was on a rubber hose and not needed disconnecting.

we’ll make do with the lighter for now.

I am however, an electrician….But my other thread is an electrical problem….

 

[Martin_E]

Often with ovens in caravans oven trays are left on the bottom of the oven whilst travelling (not on a shelf) these can do one of a couple of things…..move the tip of the electrode or crack the ceramic surround of the electrode, if the former you maybe lucky and be able to realign it.
That is of course assuming gas it getting to the oven.

 

[ProfJohnL]

Often with ovens in caravans oven trays are left on the bottom of the oven whilst travelling (not on a shelf) these can do one of a couple of things…..move the tip of the electrode or crack the ceramic surround of the electrode, if the former you maybe lucky and be able to realign it.
That is of course assuming gas it getting to the oven.

The spark electrode over the burner does seem the most likely failure, and mechanical damage is one possibility, but also it could be spillage from something being heated in the oven. But we do know the gas does work as cglittle has told us it can be lit with a lighter.

Perhaps a picture of the unlit burner and it's electrodes might help us?

 

[cglittle]

I’ll take a picture next time I’m there.
Although the inside of the oven is highly reflective… you’re going to get my ugly mug in shot!

 

[ProfJohnL]

No… I’m not gas qualified. I’d hoped it was on a rubber hose and not needed disconnecting.

we’ll make do with the lighter for now.

I am however, an electrician….But my other thread is an electrical problem….

Internal gas appliances are considered to be permanent parts of the installation, and as such they have to use durable and reliable connection systems --- copper pipes and compression couplings. The exception being the cylinder connection pipes which need to be flexible.

Where "Rubber" or flexible hoses are used with LPG, they have to be compatible with Liquefied Petroleum products, as natural rubber and several other common flexible pipe materials will be damaged by LPG.

Even the compatible flexible compounds have a limited service life and should be changed periodically.