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Leytonexile
28-08-2011, 09:13 AM
Firstly, apologies if someone else has answered this question but I couldn't find it using the search button. I have a motorhome with a three way fridge. (Dometic.) It's working fine on mains and on 12v when the engine is running but won't cool when on gas. I recently changed the burner unit and this has improved the situation but only marginally. Can anyone point me in the right direction to solve this problem?

Grizzly
28-08-2011, 11:13 AM
As all 3 power sources are there to heat the refrigerant.
Which in turn causes the chemical changes that create the heat absorption necessary to cool!
Therefore your problem still lies with the gas heat source.
I would assume that it is either poor gas flow or an incorrectly adjusted flame?
Just a guess mind!
Grizzly

sedgy
28-08-2011, 11:33 AM
hi laytonexile.
you say you changed the gas burner, has the gas burner got the correct gas injector for which ever gas you are using to give the right calorific value, is the flame < sharp<without < lifting < of is the flame yellow and sloppy< leaving black soot on the vent ?= sedgy

Leytonexile
28-08-2011, 07:23 PM
hi laytonexile.
you say you changed the gas burner, has the gas burner got the correct gas injector for which ever gas you are using to give the right calorific value, is the flame < sharp<without < lifting < of is the flame yellow and sloppy< leaving black soot on the vent ?= sedgy

Hi Sedgy

Flame looks good. Blue with a slight yellow tip. No sign of soot in the vent. If I hold my hand over the vent, I can feel warmth, which is puzzling as the fridge won't cool on gas.

sedgy
28-08-2011, 07:57 PM
hi leytonexile,
well that sounds ok , but the only adjustment there could be is if there is a screw into the burner body , between the ventura and the pilot light , you can then screw it in to restrict air flow ,
the gas injectors gas volosity drags air into the burner and mixes to give correct mixture,
the only problem is< on the legal side < is that you are requiered to hold a CITB ACS-GAS card to work on the above, let us know the outcome , all the best sedgy,

Gary
28-08-2011, 09:31 PM
Possibly a problem with the gas pressure regulator?

Magoo
29-08-2011, 03:33 AM
generally the only problem I have had with the gas side is the pilot goes out when you are not around, either blown out due to draughts and needs resetting if a new gas head

Leytonexile
30-08-2011, 07:52 PM
Many thanks to all of you for your advice. I'm happy to report, I now have a fully functioning fridge. How did this come about? You don't want to know!

What do you mean, You do want to know?

OK. Let me hang my head in shame and embarrassment!:o:o:o

Being a motorhome fridge, it's of the absorption type. These are not very tilt tolerant. My drive is on an incline. You can see where I'm coming from! It would appear the degree of slope on my drive is sufficient to prevent the fridge working on gas, but not sufficient to prevent it working on mains electricity. If anyone can explain this, I'd be grateful. A couple of days ago, I went for a one night stopover in Exeter. Before I left, I put the fridge on mains and cooled the freezer compartment down to -8c. A two hour drive on 12v dropped this to -10c. On arrival, I turned on the gas only hoping that by morning, it wouldn't be warm enough to turn the milk off. Next morning, the freezer compartment was at -16c! I was obviously parked on the level. Just a slight problem with separating the frozen rashers of bacon for my breakfast.

Grizzly
30-08-2011, 09:24 PM
Simple the refrigerant solution was still surrounding the electric heater element therefore the heat transfer was not compromised.
Had you parked your van the other way around then it probably would not of worked in 12v or mains either.

Thanks for being honest.
As I now understand one more reason why having these type of fridges level is important.
(Which I had not really considered before).
Glad all is well.
Steve.

taz24
31-08-2011, 08:38 AM
.

I was just going to say..

Make sure your fridge is level, honest I was, I was honestley, I WAS........... :)

Glad to hear you fixed it....

All the best

taz

.

mikeref
31-08-2011, 12:02 PM
Simple the refrigerant solution was still surrounding the electric heater element therefore the heat transfer was not compromised.
Had you parked your van the other way around then it probably would not of worked in 12v or mains either.

Thanks for being honest.
As I now understand one more reason why having these type of fridges level is important.
(Which I had not really considered before).
Glad all is well.
Steve.
I was surprised, Grizzly. For someone who maintains industrial systems, you have a depth of knowledge that knows no bounds. Good explanation my friend ;).

Grizzly
31-08-2011, 04:36 PM
I was surprised, Grizzly. For someone who maintains industrial systems, you have a depth of knowledge that knows no bounds. Good explanation my friend ;).

Just a thirst for knowledge like many others on the forum.
Thanks for the complement all the same, just to correct you there Mike.
My background is Industrial but sadly like many others "We" work on almost anything refrigerated (excluding transport, so far!)
As maintenance contracts seem to cover any equipment nowadays.

I find the help and assistance offered on the forum a huge benefit and where possible like to return the favour.
Keep up the good work Mike.
Thanks Grizzly.

Leytonexile
31-08-2011, 08:20 PM
.

I was just going to say..

Make sure your fridge is level, honest I was, I was honestley, I WAS........... :)


Glad to hear you fixed it....

All the best

taz

.Thanks, Taz.

I should have explained that the fridge stopped working on gas a couple of months ago, on the level(!) and I suspected the burner unit might be the cause. Having replaced it, it was quite corroded, I tested the fridge, on my drive! I should have had more confidence in my work.

Regards

Dave aka Leytonexile.

taz24
01-09-2011, 08:59 AM
Thanks, Taz.

I should have explained that the fridge stopped working on gas a couple of months ago, on the level(!) and I suspected the burner unit might be the cause. Having replaced it, it was quite corroded, I tested the fridge, on my drive! I should have had more confidence in my work.

Regards

Dave aka Leytonexile.

It sounds like it was a combination of the two, but well done on sorting it
and like others have said thanks for posting back the results.....

All the best

taz

.