thermo couple

[garydickinson]

Please don't reply with 'get a qualified gas engineer!'
1st time caravaner, Very very green and fresh to touring.
Purchased a swift challenger 2010, would like to thank previous owner from new, for letting me find out what's wrong, after purchasing gas bottles and being able to check out the items.
Anyway, right rear hob lit but wouldn't stay on (thermo couple) yes.
Purchased, fitted, tried, tested, worked even the cut out when you close the glass lid.
Found a site that let commercial vans on, (shorefield - milford on sea) all booked and ready to go, checked the tourer over, like you do, opened up the lid on the hob tried the burners, all worked apart from the one I fixed, couldn't understand why, hadn't even used it, perhaps faulty! Went away for the weekend.
Ordered another Thermo couple, and have just fitted it., All worked fine, all burners stay on, thought I'd check the lid cut off, then I remembered that was the last thing i did last time, so turned off the one I just replaced, and left 1 of the front burners on, closed the lid, cut out like it should, brilliant, tried to light the burners back up all stayed on except the back one I just renewed, a (polite oh dear). Can only assume its a faulty cut out switch?
Anyone out there that can help / give advice?
Regards Gary

 

[paws]

Hi Gary and welcome to our forums.
You may not like what I am going to say next...
Please get a competent person to check out the gas problem..... this is for your own benefit and that of folks who may use your caravan and of course, other people who may unknowingly be close to your van...

Making repairs to a gas appliance is not a suitable activity for DIY...

Happy and safe caravanning
paws

 

[ProfJohnL]

Hello Gary,
It's very unlikely a new thermocouple would be faulty. They are generally a very reliable product hence their adoption in the role as a safety gas cut of role. In all my years of using them excepting damage, l cannot recall one that failed from new. Consequently and based on your description, where you imply the ring ignites but does not maintain the flame when you release the gas control fact the problem was still present with a new TC suggests the TC was not at fault in the first place.

As the problem only affects one ring, it seems logical the fault must lie with components unique to the ring, that leaves gas feed pipes, gas valve (which includes the flame failure solenoid, the injector Venturi, and burner assembly).

For the thermocouple to work, the established flame must touch the tip of the TC to heat it up unough to generate the cut offs hold current. If the flame is weak or missing the TC then the flame failure solenoid in the gas valve will shut off the gas flow. Unless the appliance has been tampered with, it's highly unlikely the TC will be in the wrong position, so the problem is more likely something else.

I'd first be checking if the flame was burning correctly, with a tight irredecent blue base with no candle yellow tips to the flame.and no gaps in the required flame pattern. Any evidence of gaps or candling would point to a blocked Venturi, or burner crown. Being a cooker, it quite likely that the burner may have become partially blocked with debris. See the manufacturers cleaning instructions.

If the flame is smaller than it should be, it could be a partially blocked, in which case it should be replaced.

If the flame seems normally and is engaging with the TC correctly, then it throws suspicion onto the solenoid in the gas control valve. This would require the gas control valve to be replaced.

The UK Gas Safety (Installation and Use) Regulations require ALL installation, servicing and removal of any whole or part of a gas installation or appliance to be carried out by a correctly registered and qualified person. Failure to do so is a criminal offence. However a special dispensation is included specifically for privately owned touring caravans and self propelled motorhomes, for the exclusive use by the owner not used for hire or reward, whereby the owner (and no one else other than a correctly qualified and registered fitter) is permitted to carry out gas installation and servicing, BUT thecwork must still be carried out to the accepted professional standards including the design and testing of the system.

I leave that thought in your mind, and to your concience about the safety of your family or anyone else who may use the caravan.

 

[garydickinson]

Thank you forum
All 3 burners were working fine and dandy after i fitted the new TCouple to the right rear. turned it on let go of the knob all 3 working fine, let it burn for 2-3 minutes, repeated, all good, left 1 of the front burners on closed the glass lid to check safety cut out, worked fine. lifted up the glass lid, tried rear burner the same problem. (now no longer stays on),

I've not removed any GAS fittings it's all electical.

Just thought someone may have had same problem and could help,

 

[garydickinson]

Hi all
Just a quicky, should anyone else have the same problem, after checking the t/couple, (youtube) it would seem that 1 out of the 4 cut out switches for the glass lid was sticky, cleaned/drowned it with break cleaner, let it air dry whilst pushing the button continuously, checked it worked by making up a little circuit 9v battery and light bulb, refitted and all working fine, lit the burners closed the lid ok, repeated 4 more times, still good,
(Didn't have to remove any GAS PIPES,) a bit of a struggle, but there Is enough room to slide the oven forward and lift/support it, not easy job, has taken all day, if you have the money, then yes pay someone to do it, I've replaced some screws that someone has not used the correct ones, previously, (jobs worth doing do it yourself)