Dometic 7855l issues, (1 Viewer)

[Al-Di]

RM7855L
can one of you clever people look over these test results and give me an opion
the reason i ask is that on on our 1st trip out(Hawick) the fridge would not hold temp,
this was after being on mains for 3 days at home, we found that the gas side was pathetic
there was no roaring of flame at the burner just a steady blue flame,
also when home and running these test if I altered the thermostat down to no 3 it went into full defrost
and when put back to 4 it would not recover,
1st is on Electric

freezer fridge
1200 +18 +25
1300 +4 +20
1400 -8 +10
1500 -12 +8
1600 -13 +8
1700 -13 +8
1800 -15 +5
2000 -17 +3
0900 -14 +3
1200 -12 +5
3 days later on Gas
1100 +20 +22
1300 +22 +22
1500 +15 +22
1700 +8 +22
1900 +3 +21
2100 -1 +20
0900 -10 +8
1100 -15 +5

Thank you for any input, I think its fubared

 

[DP+JAY]

Flame not roaring sounds like the problem
DP

 

[Jimbohorlicks]

Check the flue and see if it needs a clean,cover up the burner first.also you can clean out the burner jets with compressed air from a can,the type that are used to clean keyboards,poundland, I cellotaped a couple of drinking straws together ,to the air can, to reach mine.

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[SandraL]

On electric the fridge dropped 15 degrees in 2 hours.
I suggest this is ok, therefore the refridgerant circuit works ok.

That means if sufficient heat is put in it will work, as the electric side does.

So gas side needs fettling. Jet blocked, flue clogged up, position of burner etc.

Generally speaking these absorbtion fridges get to about 20deg C below ambient temp at best, so 5deg C is about right. Fitting fans should improve this to 25? ish

 

[Al-Di]

Check the flue and see if it needs a clean,cover up the burner first.also you can clean out the burner jets with compressed air from a can,the type that are used to clean keyboards,poundland, I cellotaped a couple of drinking straws together ,to the air can, to reach mine.

yes done all of that and put new jet in,my main concern is(from previous posts) I do not get any form of roar from the burner, and if I alter the thermostat it makes no difference to the flame, it just sends it in defrost from which it will not recover,

please keep idea's coming, thank you,

 

[Jimbohorlicks]

Have you tried cleaning any crud off the thermostat tip where the flame is? Or even change that thermocouple? If it's not reacting to the flame it will not open the gas valve.
From your test results its OK on electric and OK on gas eventually, it's just slow getting there on gas.
I would opt for the thermocouple on the burner.

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[Al-Di]

Have you tried cleaning any crud off the thermostat tip where the flame is? Or even change that thermocouple? If it's not reacting to the flame it will not open the gas valve.
From your test results its OK on electric and OK on gas eventually, it's just slow getting there on gas.
I would opt for the thermocouple on the burner.

its a bit pricey just on a guess,

https://rover.ebay.com/rover/1/710-...0001&campid=5338547443&icep_item=372371944041

 

[bigtwin]

My fridge has never roared when on gas! Just a nice hot blue flame.

Ian

 

[Jimbohorlicks]

its a bit pricey just on a guess,

https://rover.ebay.com/rover/1/710-...0001&campid=5338547443&icep_item=372371944041

It's still cheaper than a fridge though.
Again from the results you quoted, it does cool down eventually. I would at least recheck the jet. Have you taken it out and cleaned the gas pipe and blown through the jet. If you have, how about trying a new jet.?

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[Graham of Madrid]

What were the ambient temps?

 

[Graham of Madrid]

I don't think 12 hours is unreasonable to expect the temps to drop to acceptable / usable levels

 

[DP+JAY]

yes done all of that and put new jet in,my main concern is(from previous posts) I do not get any form of roar from the burner, and if I alter the thermostat it makes no difference to the flame, it just sends it in defrost from which it will not recover,

please keep idea's coming, thank you,

Strange, the burner is very audible on this & previous van.
DP

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[bigtwin]

Strange, the burner is very audible on this & previous van.
DP

Say again!

Ian

 

[Al-Di]

yes on our previous van you could hear the burner fire up
right have ordered a new burner and another jet(which i have changed already)
have also pulled my shotgun cleaner up through the chimney(bloody tight),

please keep idea's coming we may get there,

 

[jockaneezer]

With the vent in place and standing within a couple of feet, you should be able to hear a feint "roar" from the burner (as long as your hearing is ok !)
My flame had a lovely blue hue to it, no roar and the fridge was defrosting. I removed the jet from the pipe and blew through it but also got the missus to briefly switch the fridge onto gas (careful now !) for a second and blew some rust particles from the supply pipe. All was fine after that.
Other things to think about is maybe your regulator is on the way out, does your hot water/heating work ok ?

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[Al-Di]

had all pipes off blown through smaller ones, bottle brushed bigger ones,
water heating cooker all work fine,
waiting on this new burner then see what happens,

keep them coming thanks,

 

[Al-Di]

Update time,
new burner and jet fitted Jimbohorlicks
test figures over last 3 days

freezer fridge
1300 25 25
1700 -9 18
1900 -12 15
2100 -14 12
0900 -18 2
then turned stat to no 3
1100 -14 5
1300 -15 5
1700 -5 10
turned stat back to 4
1900 -12 8
2100 -14 8
0900 -18 2
1100 -18 2
1300 -17 2
1700 -16 3

so we may have a working fridge, what do you lot think, and would a fan kit improve it any
Thanks all for the input

 

[Jimbohorlicks]

The temps look to be ok, - 18 in freezer, that's really good. Seems to have cured your problem. A fan in the upper vent area on a thermostat will help keep the fridge cooler, probably at a lower setting and save you some gas.
Well done in persevering and sorting the problem.

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