Thetford fridge freezer

[dakota]

I have a 2010 autotrail savannah with a thetford fridge freezer with auto function , ive just had my van serviced this included the fridge and no one seems to be able to sort my problem , which is through the day working on gas everything goes well no probs , but at night it keeps going off , i relight it 2 or 3 times over night , now ive heard of fridges not working because of a cold envoirenment so im wondering seeing as the temperatures go down so much at night is this the case with my fridge and what can be done about it anyone got any ideas because im losing loads of sleep through it , thanks . (?)

[Wooie]

Do you use the " Vent Covers " when the temperature cools at night ?

[Keithl]

Are you using Propane or Butane?

 

Butane won't 'gas off' at low temps (below approx 5 deg C) so will not work when it's cold at night.

 

Keith.

 

Edit. Or are you using refillable cylinders? Some LPG has a higher concentration of Butane then Propane so the situation above may occur.

[dakota]

Yes i use the vent covers if its windy but it has still happened with them on , and im using calor propane , the evening temps have been down a bit lately , so i reckon i need to see if this gets better when the temperatures warm up , thing is ive always used propane and never had this problem with other fridges .Does this mean i may have to switch to butane for colder nights ??

[Keithl]

dakota - 2013-05-27 6:29 PMDoes this mean i may have to switch to butane for colder nights ??

 

No! Propane is the one to use. See my reply above.

 

But sorry I couldn't help with your original problem :-(

 

Keith.

[dakota]

Thanks for your answers , ill just have to carry on using the vent covers at night untill the nights get warmer i reckon .

[Derek Uzzell]

The purpose of fridge vent-covers is to improve the performance of the appliance when the outside temperature is below 8°C, or to minimise water ingress when the leisure vehicle is being cleaned or during winter storage.

 

Fitting a cover to a lower ventilation grille MAY help to avoid a fridge's gas-flame from blowing out if the weather is very windy and the vehicle is parked with the grille facing the wind's direction, but the gas-burner is (or should be) well shielded, so such occurrences should be rare.

 

As propane (boiling point of -42°C) is being used, choice of gas is not an issue.

 

I've no hands-on experience of Thetford fridges, but I'd expect dakota's fridge/freezer to function on gas in a similar manner to my Dometic model, with the gas-flame shutting off and relighting automatically according to the temperature within the appliance's interior. If that's correct, even if the gas-flame blows out it should be expected that the gas-burner should relight without human intervention.

 

If the problem never occurs during the day it's logical to assume it's outside-temperature related, but I suspect the fault's electrical and that the addition of winter covers is a red herring.

 

Presumably the appliance indicates that it's gone into 'fault mode' (a flashing LED?) that warns dakota that he needs to react. That he is able to relight the gas-burner when this happens suggests that it's the appliance's automatic relighting function that's problematical.

[HWO]

We found with our Savannah that if the off- side was not level or was lower than the on-side the fridge door would not be shut properly. there is a micro switch built into the catch/light unit inside the fridge. The small blue light in the control panel would flash for a bit and then the fridge would turn off.

 

If we could not get levelled up enough , we would leave the travel catch on all the time to make sure the door was properly shut. That cured our fridge shutting down problem.

 

HWO

 

[dakota]

Derek , you have a valid point with the theory of an automatic relighting problem except that through the day the fridge/freezer does go off and relight automatically i hear it do so , but through the night it doesnt unless i do it manually , this can only be because of the cold , i used to think it was the wind but even with the covers on it still happens , and as you say the flame is well covered anyway and when the covers are on the temperature in the fridge/freezer warms up slightly which isnt a good thing when youve got stuff in the freezer as well , so ill have to wait untill the nights get warmer [ if that ever happens ]

and see if that solves my problem .

[woodburner5]

dakota, It sounds very much like the thermo couple is just out of tolerance with the flame, seems possible the engineer has nudged it undertaking the service, Get your engineer to check this out and reset the thermo couple position.

 

Hope this helps.

N

[Derek Uzzell]

woodburner5 - 2013-05-29 1:18 PM

 

dakota, It sounds very much like the thermo couple is just out of tolerance with the flame, seems possible the engineer has nudged it undertaking the service, Get your engineer to check this out and reset the thermo couple position.

 

Hope this helps.

N

 

If dakota's Thetford fridge had suddenly begun to exhibit at-night relighting problems after the recent service had been carried out, it would be logical to blame the servicing. I'm not sure that's the case, though, as the conclusion is a natural one and I'd expect dakota to have demanded that whoever performed the service should fix the problem.

 

I get the impression that the problem existed prior to the service, was mentioned as something that needed to be addressed during the service, but continues to persist "and no one seems to be able to sort..." it out.

 

Perhaps dakota could confirm whether or not the problem was evident before the recent service as well as after?

[dakota]

You are correct this problem was evident before the recent service and is still happening , no one seems to be able find the problem , im going away for 17 days next week ,the first week is on ehu so no probs there , i hope the next 10 nights wil be warmer just to prove the gassoff theory , if not then ill be taking the van back to the people who serviced it and let them have another look and i will mention the thermo coupling .

[dakota]

After searching fo a possible cause for my problem , there seems to be a number of people saying theyve had this problem and when the thermal coupling has been adjusted it has sorted the problem of night time shut downs [ again possibly caused by cold temps quickly cooling the coupling ] ive had a look at the thermal coupling on my fridge/freezer and it looks to be about 3 mm from the flame / burner , it does glow red when the burner is on , so has anyone out there got any idea what the spec /distance should be for the coupling to the burner , i would have thought it close enough .

[Derek Uzzell]

I suggest you ask Thetford about this

 

http://www.thetford-europe.com/en/contact.aspx

 

I note that (in a MotorHomeFacts thread) it is said that, on a Thetford fridge, the thermocouple also acts as the gas-igniter. If that's true, then the position of the thermocouple may well be critical.

 

In principle, as the tip of your fridge's thermocouple glows when the gas-burner is operating, it should be hot enough to perform its flame-failure function. Obviously, the tip does need to be within the flame but, otherwise, I would not have thought it's exact position would be that important. However, if the thermocouple is dual purpose, it's position may be OK regarding detecting flame-failure but the 'gap' between its tip and the burner may be too wide (or too narrow) for a strong spark to be produced.

 

This link is to Thetford fridge trouble-shooting advice

 

http://www.swift-owners-club.com/support/oem_handbooks/thetford/troubleshooting_fridges.pdf

 

The advice for Error code 9 is that the electrode gap should be set to about 4 mm above the burner, which suggests that your "about 3mm from the flame/burner" should be OK. You could try experimenting with the position of the thermocouple/igniter to see if you can obtain a stronger spark and/or a brighter 'glow'.

 

Unless the problem worsens to the point where it occurs during the day (and can then be demonstrated to a technician) its cause will be hard to diagnose. It's probably not practical but, as you'll be familiar with the sound your fridge makes when it relights successfully, it might be possible to tell whether (when it fails to relight) the igniter does not 'fire', or the igniter fires as normal but the gas fails to light, or the gas does light and then the fridge switches off. This could help point to where the problem lies.

 

Unless the parts (eg. the thermocouple) at the burner assembly are badly out of position - which one might have thought would have been apparent during the recent service - I can't see a lower nightime temperature affecting those components. However, these modern fridges have a lot of electronic bits and these (eg. the ignition module) might develop temperature sensitivity resulting in a sporadic fault..

 

[dakota]

Thanks a million derek for your info especially the troubleshooting pdf ill keep that for future reference , over the next couple of weeks ill be using the fridge so im hoping everything goes ok , this time im better armed with info about it so if anything happens ill be able to analize it better . ;-)