16' Series Dometic freshjet 3200 disapointing

WogsRus

New Member
May 14, 2020
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Hobart TAS, Australia
So my jayco came pre-wired and set up for a roof top ac. Once I got all the drawings and the like from jayco, i purchased a dometic freshjet 3200 as I was after the reverse cycle heating function. (Ps I'm a mechanical engineer by trade hence me being pedantic)

I installed the AC today, very easy and happy with the install, however in heating, the thing is useless.

It is suppose to have 2.4 kw of heating rated, which for out 16.49-4 van, should be shitloads.

I've had the unit running for a few hours, its 10 degrees outside and I can nearly get 18bdegrees inside...

Wtf, the unit was recommended by our local guys and on spec, looked really good.

Our $250 diesel heater in the old van was 10 times better.

Cooling seams ok.

Anyone had similar issues?

How does your AC works?
 

Drover

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Nov 7, 2013
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Big Mal originally had a Dometic B3000, cooling was good, heating not bad, tested July in Canberra but the whole unit would rock the van when doing a restart and was a horrible noisy beast, thanks to a hail storm I now have an Aircommand Ibis III, whisper quiet, chills really well and the heater does need turning down, Big Mal is a 23ft rig so needs some air flow and we are very happy with the Ibis, can sleep during the night without it waking you up all the time thinking an elephant has landed on the roof.
 

BJM

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Sep 29, 2018
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Yamba
There is someting wrong with the unit.You should nearly have to throw all your gear off even at 10c with the heating specs of the unit.I presume your van is not a poptop as they will loose more heat than normal van..but still should heat well.test the hot air temp coming straight out of the unit at roof level.This will tell you a lot of info.plus is cooling working as it should?
 

WogsRus

New Member
May 14, 2020
24
7
3
Hobart TAS, Australia
The unit is a poptop, hence why I went for the bigger unit due tonhear loss.

Given my background, mech eng, is why I'm asking the question as the unit should certainly be heating much more then it does.

Additionally, you set it to say 22 and it turns off when it gets to 17 deg c as if it had reached temp, which isn't the case, even the remote tells you that it hasn't reached temp.

Have written to dometic to see what we can do.
 

WogsRus

New Member
May 14, 2020
24
7
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Hobart TAS, Australia
Ok so went outside to test this morning. The inside van temp was 13. I Turned the unit on, set to 24. Unit compressor kicks in, a bit to noisy seams like something is rubbing, the air on the outlets runs all the way to 31 deg c, whcih is very warm, but the unit only runs for about 4 minutes at this ten the fan turns back down and unit compressor cycles on and off with the air dropping back down to 26 or so....
 

Drover

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Nov 7, 2013
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I have found auto settings do that sort of thing, I always go heat setting and manual fan otherwise they tend to cycle hot/cold/hot/cold van or house.
 

WogsRus

New Member
May 14, 2020
24
7
3
Hobart TAS, Australia
Well been all day and still disappointed. The only way I can get the space to being close to 22 degrees c is to have it on heating 31 deg and full blast on the fan. And its 16 outside.

Time for a call to dometic Australia to get some performance testing data.
 
Last edited:

Drover

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Keep us in the loop then be interesting to see the outcome ...................... I recall problems with a thermostat position someone had but then that was affecting cooling not heating.
 

WogsRus

New Member
May 14, 2020
24
7
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Hobart TAS, Australia
Will do, doing some more testing, one thing i found is that the return air temp, even after 2 minutes of operation, reaches 20 degrees c, like we have leakage or something around the plenum. Maybe look into getting some 2mm expanded foam to provide wetter insulation on the plastic plenum.
 

WogsRus

New Member
May 14, 2020
24
7
3
Hobart TAS, Australia
Ok so found the issue, the unit throws out very hot air when in heating, sub 42 degrees c, to spec more or less. The issue is that in a 16ft van, that air forms a stratified hot air layer, on the roof, and within minutes sits at well over set point temperature.

As the return air sensors is what cycles the supply air to deliver hot air and drives the compressor, the heating turns off.

SO unless i can find a way to de-stratify the hot air layer and or move the return air sensor from the unit onto a wall, doable as i looked today, the heating issue will exist for ever.

DAM IT
 
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BJM

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Sep 29, 2018
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Isnt the 3200 model meant to heat cool larger motor homes ,caravans as well ? You would think the lower vents in the door etc would let the hot layer quickly displace out the cooler lower layer.! Still doesnt sound right ,plus there should be other dissatified customers.If this does turn out to be the problem I would complain to Dometic.Not really fit for the purpose.
 

Drover

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So it is thermostat position, I would have thought vent adjustment would sort that sort of thing all I could think of to test/check would be a wall mounted fan to circulate the air, might help narrow the possibilities.
Notice on the ibis the air is drawn in from the centre of the unit with the outlets on 4 sides, thusly forcing the hot/cold air away from the unit.....my earlier Dometic didn't, blew fore and aft and drew in from side, might have been why it was a bit of a pain at times.
 

WogsRus

New Member
May 14, 2020
24
7
3
Hobart TAS, Australia
Well all i can say is that the unit is useless on heating, period, and i mean unless. I spoke to dometic tech yesterday and until i can get the van to service, we wont know.

The unit draws cold air in through the center, but form what i can see, cant throw the air far enough to mix it so stratifies the hot air and thats it. Unit turns off as soon as return air temp get to set point, even though the room is stone cold.

And the 'I feel' Function is uslessssss. Yes it works by using the room sensor to adjust unit output, however, as it still has some interaction with the return air temp sensor, the unit still turns off to prevent the unit going out on High Pressure alarm on the compressor due to high discharge temperatures, wonderful.

I even built a 40mm drop box to lower the main discharge plenum off the roof, made no differance.
 
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WogsRus

New Member
May 14, 2020
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Hobart TAS, Australia
Well full day of testing for the same disappointing results. I went as far as taping on some clear plastic diffuses to blow the air down to the floor to try and get the unit to work better and within 3 minutes return air temp reaches like 28 and unit shuts off.

Off to Mr service center and speak to demotic as i certainly am not happy.

Now i know people will say its an conditioner not meant for heating, sorry, but when you spend 2 K for unit with 2.4kW of heating capacity with an ambient air temp of 10 degrees C and not being able to get a 16 foot caravan to 22 deg C is bullish and fundamentally, the design of the air distribution box is crap.
 

Drover

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Nov 7, 2013
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On the flip Side, cooling works a bloody treat, and i mean a treat, it cools rally fast and really well. LOL. Silver lining.....

ah yes but the outside temp was what ?????? ....... It might also be rubbish when the outside temp is in the 30's and climbing............ I would be banging on a table if I had just bought the thing certainly not up to par, its just annoys the crap out of me when this happens and I really hate having to do it.......
I do hope it gets a good resolution for you...........
 
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WogsRus

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May 14, 2020
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Hobart TAS, Australia
All good mate, totally understand., mechanical engineer specializing in HVAC hence why i;m commenting on the issues with the Air Distribution box and poor design.

FYI, this is a clip taken this morning of the unit starting up and the compressor noise, yes will be taken up with Dometic, however just wanted to post it for other to listen to, probably form about 56s onward.

 

Drover

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Thats is BS, I put my sound meter on the desk and it was popping at 58 to 60db, I'll see what Big Mals Ibis does tomorrow, my diesel heater which sounds like the APU of an aircraft starting up isn't that loud.................