Poor Fridge Performance (1 Viewer)

[bigtwin]

We have a Dometic TecTower in a 2012 vehicle and have been struggling with the performance of the fridge (freezer is fine) on EHU and gas.

Ordinarily, I’d have put the blame on deterioration of the thermal paste. However, I have replaced the paste with the GD900 that uncle Lenny HB recommends and this has made little difference.

Would too much, as well as too little, paste be detrimental to performance?

The gas burner appears to be fine with a good healthy flame.

Access to the top of the flue is impossible without removing the fridge but I have blown air up through the flue with no significant soot/debris coming out. I have also ‘brushed’ the lower part of the flue with a rag attached to fibre cable ‘mouse’ again with no evident dirt/soot being visible.

Any other suggestions on what the root of the issue might be? I had contemplated the cold air escaping out of the bottom of the door seal but that doesn’t seem to be the case.

Ian

 

[TinaLes]

Check out the many threads on adding Fridge fans, both at the rear top exit vent, and also one inside the fridge to help circulate the air inside the fridge with cheap Chinese thermostats to switch on/off at required temperatures.
I would start with 2 fans pulling the heat out the top vent first, you should see an instant improvement on hot days especially. Ready made kits are available, or you can simply use good quality computer as as many have.
LES

 

[bigtwin]

Check out the many threads on adding Fridge fans, both at the rear top exit vent, and also one inside the fridge to help circulate the air inside the fridge with cheap Chinese thermostats to switch on/off at required temperatures.
I would start with 2 fans pulling the heat out the top vent first, you should see an instant improvement on hot days especially. Ready made kits are available, or you can simply use good quality computer as as many have.
LES

Thanks for your response, the fridge has previously performed satisfactorily without fans and I’ve been testing the fridge over the past week when we’ve had cooler ambient temperatures.

I omitted to say that I have fitted cooling fans to this vehicle (and on our previous van).

The freezer is fine, it’s just the fridge that is struggling. Temperature first thing in the morning is only getting down to 8°C.

Ian

 

[DavidG58]

What setting are you using, we find 2 is cooler than anything else , highest it actually gets less cold

 

[bigtwin]

What setting are you using, we find 2 is cooler than anything else , highest it actually gets less cold

Ive tried it on both 3 and 4. I’ll give 2 a try later on as I’ve just pulled the temperature sensor off the fins (so that it’ll read a higher sensed temperature) to see if that makes a difference.

Ian

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[TinaLes]

bigtwin does the fridge temp vary between using 240V or Gas?
Gas is normally favourite for some reason, but I have to say these AES 3 way fridges are no where near as good as compressor ones, but compressor types do draw a lot more current.
Might be an obvious question, but I take it you have checked the fridge seals are making good contact, it might be a wise move to clean and lube them up with some silicon spray.
Other than that as the gas burner seems OK, and the 240V/12V elements it would then maybe need a Dometic service engineer to check its fully gassed, and the temp stats are working OK.
PS: we had a problem with our van when new, the problem was storing the van on our elevated drive, the cooling fluid took 4 plus days to settle back down at the bottom of the cooling loop, before it started to circulate properly.
Good luck.
LES

 

[rosalan]

Too much thermal paste will not work. A much earlier answer suggested the paste thickness (I forget exactly) should be minute. I got it wrong first time. The screws that hold the fins on should be quite tight to make sure of best contact to the cold freezer pipe behind. The process is rather crude and simple, also able to fail . Answer if it does not work, do it again.
Normal setting is 3

 

[bigtwin]

@bigtwin does the fridge temp vary between using 240V or Gas?

Not noticeably so.

Gas is normally favourite for some reason,

Agreed and this is why I have focused on gas use during my investigations.

Might be an obvious question, but I take it you have checked the fridge seals are making good contact, it might be a wise move to clean and lube them up with some silicon spray.

I have had a cursory look but will perhaps have a more detailed look. The air at the bottom of the door isn’t obviously cooler than ambient but perhaps it’s time to dig out my infrared thermometer to check a bit more accurately.

Good luck.

Thanks Les.

Ian

 

[1967bowesj]

Does moving the temp sensor affect things much.
Our 8505 started to be a bugger in last France trip, ended up froze over when gas started to circulate after it stopped when we parked on a slant. Took 4 days to right itself. Was not the same after so not sure gas/liquid settled 100%

 

[bigtwin]

Does moving the temp sensor affect things much.

Hard to tell but it hasn’t resolved my issue.

In theory, the fins should be the coldest point in the fridge and the sensor is measuring the fin temperature such that when the sensor detects that the fins are cold enough, the heat source would be switched off (hence stopping the refrigeration process). By moving the sensor off the fins, the sensor would see a slightly higher temperature so would keep the heat source on (and hence keep the refrigeration fluid circulating) for longer as it tries to lower the temperature seen by the sensor.

Ian

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[mitzimad]

have you cleaned or changed the jet even a flame that looks good isnt enough you should be able to hear it roaring through the vents?

 

[1967bowesj]

Hard to tell but it hasn’t resolved my issue.

In theory, the fins should be the coldest point in the fridge and the sensor is measuring the fin temperature such that when the sensor detects that the fins are cold enough, the heat source would be switched off (hence stopping the refrigeration process). By moving the sensor off the fins, the sensor would see a slightly higher temperature so would keep the heat source on (and hence keep the refrigeration fluid circulating) for longer as it tries to lower the temperature seen by the sensor.

Ian

Agreed, I know when ours was playing up I moved it down the fins and it made a large difference so removing it should have the circulation in over drive. If it works ok on 240v and 12v but not gas then it’s not a sensor or paste issue it must be the burner

 

[bigtwin]

have you cleaned or changed the jet even a flame that looks good isnt enough you should be able to hear it roaring through the vents?

The issue is the same whether on EHU or gas, and the freezer is working fine.

I can hear the burner fine through the vents.

Ian

 

[bigtwin]

If it works ok on 240v and 12v but not gas

It’s the same on all power sources.

Ian

 

[1967bowesj]

Could be the refrigerant has a blockage, that’s a fridge out and stand it upside down then return leave for gasses to settle then test. Not a guaranteed fix but sometimes works.
Have you smelled any ammonia type smells? Gas leak? refrigerant leak

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[Flairy]

I’ve just put the latest Dometic burner in our fridge it’s working better,because before it was sometime firing but not always.Now it’s running nicely on number 3 it’s -15 in the freezer between +5 +8 in the fridge and that’s as good as it’s ever been,I have twin fans it doesn’t seem to make a difference.that temp is at about 28 degrees.Plus my old world fridge mod done in Germany.See you at Malvern

 

[WESTY66]

Just gone through all this with our tec tower fridge, fine in Croatia in 36 degrees in 2022, then last year in Obernai the fans packed up and well really it’s been crap for 18 months, so I thought it’s not going to beat me, new door seal, new fans 3 at top pulling out, 2 at bottom shoving in, then I buggered the burner up, so I put new burner on it and this was it yesterday

In the full glare of the sun at the side of the vents
Top temp = freezer
Middle temp=fridge
Bottom temp, in the full glare of the afternoon sun.
On gas and at No4

Happy with that

Flairy ill pop by at malvern and say hello

 

[1967bowesj]

I’ve just put the latest Dometic burner in our fridge it’s working better,because before it was sometime firing but not always.Now it’s running nicely on number 3 it’s -15 in the freezer between +5 +8 in the fridge and that’s as good as it’s ever been,I have twin fans it doesn’t seem to make a difference.that temp is at about 28 degrees.Plus my old world fridge mod done in Germany.See you at MalvernView attachment 934862

See now that’s how old fridges used to be, vented directly outside, no residual heat in the cavity.

 

[Richard n Ann]

Do the aluminum fins inside ice up, or just condensate?
What is the ambient temperature?

 

[Flairy]

Just gone through all this with our tec tower fridge, fine in Croatia in 36 degrees in 2022, then last year in Obernai the fans packed up and well really it’s been crap for 18 months, so I thought it’s not going to beat me, new door seal, new fans 3 at top pulling out, 2 at bottom shoving in, then I buggered the burner up, so I put new burner on it and this was it yesterday
View attachment 934864
In the full glare of the sun at the side of the vents
Top temp = freezer
Middle temp=fridge
Bottom temp, in the full glare of the afternoon sun.
On gas and at No4

Happy with that

Flairy ill pop by at malvern and say hello

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[Flairy]

I look forward west66

 

[WESTY66]

I look forward west66

You might regret it, ask a few on here

 

[Flairy]

I’m afraid we haven’t got any biscuits

 

[1967bowesj]

I’m afraid we haven’t got any biscuits

He won’t be put off, he can smell them out lol

 

[WESTY66]

I’m afraid we haven’t got any biscuits

There’s time to go shopping don’t listen to that Coastal Cruiser. he’s a bad man

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[Flairy]

I’ll go shopping

 

[Coastal Cruiser.]

I look forward west66

I wouldn’t

 

[Coastal Cruiser.]

There’s time to go shopping don’t listen to that Coastal Cruiser. he’s a bad man

I have had to sell my van just to stop you hounding me around Europe

 

[Flairy]

That’s very extreme

 

[bigtwin]

Could be the refrigerant has a blockage

The refrigeration cct is good otherwise the freezer would be affected and it’s all good.

Have you smelled any ammonia type smells? Gas leak? refrigerant leak

No, nothing on that front.

Now it’s running nicely on number 3 it’s -15 in the freezer between +5 +8 in the fridge and that’s as good as it’s ever been

That’s similar to what I’m experiencing but the fridge temperature is too high (and higher than previously experienced).

Plus my old world fridge mod done in Germany.

I shall have to ask you about this at Malvern.

See you at Malvern

I shall look forward to it.

Ian

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