Thetford gas oven

[Woodster]

Help please our Thetford oven in our new motorhome has decided not to work we are currently in Scotland it has worked fine for 5 days but every time we try to light it fires up ok but as soon as you release heat control button it goes out no matter what Any ideas please.

 

[Stealaway]

You should be able to see the safety thermocouple. It's probably been dislodged. Move back to where the flame is on it constantly.

 

[Two on Tour]

The part of the thermocouple that the flame plays on can get coked up with grot from time to time and this coking can acts as an insulator.

 

[Two on Tour]

Are your gas rings staying alight ?

 

[Woodster]

Yes gas hob working fine just the oven being a pain lights ok but as soon as you let go of the temperature control knob it goes out. many thanks for your help. Mick

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[XxAnthxX]

As already mentioned ensure the thermocouple is clean and in the pilot flame.....if that doesn’t work replace it.

 

[MisterB]

as most have suggested, its thermocouple related. without getting too technical or telling you what you might already know, the thermocouple is a bi metallic strip that sends a small (minute) electric current when its heated, that 'signal' is enough to hold open the gas valve to allow the oven (or boiler) to ignite. when you hold down the control knob, it allows a small amount of gas to pass to the pilot light (which is a very small pipe with a little burner or opening at the end) its the flame from that that heats the thermocouple which then sends the 'signal'. if the pilot light flame goes out when you release the control knob, then its usually an issue with the thermocouple either not being heated because its sooted up, not actually in the flame of the pilot light (so therefore is not being heated) or is faulty.

you can buy universal thermocouples for around £5 that fit 90% of appliances or the actual one for your appliance - its a simple fix though sometimes a bugger to get at! if it is a real pig to access, i think i would be looking at replacing with a new thermocouple rather than spending ages getting to it, if easily accessed then try cleaning it with a bit of very fine emery cloth and making sure it sits within the flame of the pilot flame when youre trying to light the oven

 

[Minxy]

Daft question, but is it windy? Could the wind be getting in the external vent at the rear and causing an issue?

 

[Woodster]

I take your point about sooting up but the m/h is only 5 days old so I would hope that wouldn’t be an issue? Looks like it’s bloody salads from now ON.

 

[125BEER]

I take your point about sooting up but the m/h is only 5 days old so I would hope that wouldn’t be an issue? Looks like it’s bloody salads from now ON.

Bbq ?

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[XxAnthxX]

I take your point about sooting up but the m/h is only 5 days old so I would hope that wouldn’t be an issue? Looks like it’s bloody salads from now ON.

Yeah sounds extremely unlikely......just check the probe is in the flame, even check the nut at the gas valve end if it’s easy to get at.

 

[Woodster]

Funny thing is that both oven and the grill are doing the same thing light up straight away then go out. Three burner hob is fine.
Thanks everyone for your input and help,

Much appreciated

 

[cmcardle75]

I take your point about sooting up but the m/h is only 5 days old so I would hope that wouldn’t be an issue? Looks like it’s bloody salads from now ON.

Sounds like a warranty job, then! (Assuming that you're holding it in long enough before releasing).

 

[XxAnthxX]

Funny thing is that both oven and the grill are doing the same thing light up straight away then go out. Three burner hob is fine.
Thanks everyone for your input and help,

Much appreciated

I guess you’ve tried holding the Knob in for longer (pardon the expression )......just to try to get some more heat into the thermocouple?

 

[Two on Tour]

Our Thetford hob and oven two separate units rather than an all in one and if the OP's is the same then if the hob is okay it might be the thermal cutout in the oven/grill that's gone west which will break the the circuit of the thermocouple.

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[MisterB]

if its got a thermal cut out (high temp stat) then a universal thermocouple shouldnt be fitted - you can tell by looking at the thermocouple, if it has wires coming from it then you need to get the specific replacement

as for sooting up, if it is new than the burners might not be correct or the operating pressure set right (if there is a way of adjusting the burner pressure) - which would also affect the gas flow through the pilot light. if its too rich then sooting could occur quite quickly. it would be unusual after only 5 days (and non continual use) though. if you can see the flame when holding in the control knob, is it yellow and smokey or blue and clean?

 

[Woodster]

Thanks everyone but now sorted spoke to the gas technician at Becks and the problem was solved by putting a small piece of tissue in the control knob. This restricted the control knob so didn’t go in so far. So hopefully all good.