Frustrating problem with fridge on Gas - Dometic RMD 8505 (1 Viewer)

[namwaldog]

The Fridge on our van, a 2010 Burstner Solano has worked properly for the 15 months we have had it until now..
I had to uncouple the gas bottles in the locker and then re- connect them. Bled the gas through the hob no problems, so cooker and heater work fine on gas .
Fridge works on 12v and 230v no problem. When I switch it over to gas (or having AES, it selects gas) the display alternates between "AES" and "GAS" as it should and the blue "on" light displays for about two minutes then flashes red and simultaneously the red "failure" triangle flashes and a "beep" alarm sounds. I should say at this point that I cannot hear any clicking as though trying to ignite.
The manual gives the advice below....

There IS gas in the bottles.
The Shut off device is open
There is gas in the pipes at the back of the fridge at least up to this elbow...

I have 'switched the appliance off and started again' until my finger is worn to a stump but still cannot get it to work on gas.

I searched the internet for answers and found on another forum that it is possible to reset an appliance with a similar Dometic number after gas disconnection by pressing the red flashing triangle for a couple of seconds but there is nothing to press on mine..

I have filled in an online enquiry for with Dometic but it was rejected as it did not support the "Article No" that I supplied!!
There is electrical power to the appliance so can I rule out a blown fuse?

Anyone any suggestion before I call out an engineer?

This is the spec of the appliance..

I am reluctant to try and get to the burner to blow it clean as it is not very easy access and I can't see what I am doing other than with a reverse image in a mirror which makes my head hurt

 

[Hettie's Crew]

Whilst ours is an 8505 (2014) it looks different to yours, when this happens on ours we press and hold the alarm button rather than the on off button. Then it resets and try’s to get gas again.

 

[peterc10]

Whilst ours is an 8505 (2014) it looks different to yours, when this happens on ours we press and hold the alarm button rather than the on off button. Then it resets and try’s to get gas again.

Yep, that's what we do with our too.

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[Just smiffy]

Could be that disturbing the system has caused a bit of debris to block the jet...?

 

[Lenny HB]

Whilst ours is an 8505 (2014) it looks different to yours, when this happens on ours we press and hold the alarm button rather than the on off button. Then it resets and try’s to get gas again.

Same here, its looks nothing like the 8505 with have had on the last two vans.

If its not trying to light it is either the ignition module or its not getting the right signal from the control panel.
Worth checking the ignitor & flame failure leads, I had them burn through the insullation on my last van, but normally still clicks but tracks to earth.

 

[DavidG58]

we have an 8555, still a pile of cr@p but we get similar issues to you when our gas runs out

If left on AES it never relights the gas, we don't have a fancy alarm option, but I always have to remember to either turn off and back to AES, or turn to gas to light, then back to AES, it always lights then

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[The Dudess]

Our MH is currently at the dealers because the fridge won't work on gas despite pressing the reset button a million times. Got the cover off and managed to check that it was sparking but no flame. Took it to a Dometic engineer in Spain who took an air gun to it in case it was debris but this didn't make any difference. Will let you know if the dealer has fixed it and what he has done. Although it's not the same model it may give you a clue.

 

[The Dudess]

@namwaldog
Hi Barry, Just got our MH back from the dealers and they have fixed the fridge not workinf on gas problem. It was originally thought to be a gas valve which needed replacing, however replacing this did not cure the problem. They have now changed the control unit and the problem appears to be solved. I asked for the part number but because most of the staff are away at Newbury show they didn't know what it was. Hope you manage(d) to get yours fixed.

 

[Mr B]

We have the same as you.
Can you select gas only from the panel?
Does it try to ignite then?
Might be a loose/broken igniter.
Sorry, can’t help any further.
I know ours was struggling on gas when we were in the south of France last year.
I ended up giving the burner/flue a little tap, and the noise of the burner suddenly got a lot louder..... result was cold beers and ice for the Gin

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[Duck Truck]

cold beer and Gin
All on tap?

 

[namwaldog]

Thanks for all the advice. Still not sorted but I am learning a lot !!

I have identified the gas valve and disconnected the gas-out port and tried to switch on the fridge but there is no gas coming out of there.
I have checked the electrical connections to the gas valve with the multimeter but cannot find any current there trying to open the gas valve. There are three wires to the gas valve and tried different combinations with the probes but cannot get a reading.
I have checked the Printed Circuit Board and am getting readings on both the A.C. and the D.C. supplies to their respective feeds to the fridge but cannot get a reading on port X110 that feeds power to the GFA box. The GFA box controls the power to both the gas valve and the burner ignition system.

This leads me to suspect a fault on the PCB but I am still groping in the dark so I am not drawing any conclusions.

I would appreciate any advice on how the gas valve works so that I gan isolate it from the onboard power supply and try to open it via an independent power supply to eliminate that from the problem.

The three arrows show the electrical connections to the gas valve. Is the yellow arrow, the earth?

The gas valve is shown within the red square as GV 100.
Thanks

 

[Makingtrax]

The Fridge on our van, a 2010 Burstner Solano has worked properly for the 15 months we have had it until now..
I had to uncouple the gas bottles in the locker and then re- connect them. Bled the gas through the hob no problems, so cooker and heater work fine on gas .
Fridge works on 12v and 230v no problem. When I switch it over to gas (or having AES, it selects gas) the display alternates between "AES" and "GAS" as it should and the blue "on" light displays for about two minutes then flashes red and simultaneously the red "failure" triangle flashes and a "beep" alarm sounds. I should say at this point that I cannot hear any clicking as though trying to ignite.
The manual gives the advice below....
View attachment 232019
There IS gas in the bottles.
The Shut off device is open
There is gas in the pipes at the back of the fridge at least up to this elbow...

View attachment 232020

I have 'switched the appliance off and started again' until my finger is worn to a stump but still cannot get it to work on gas.

I searched the internet for answers and found on another forum that it is possible to reset an appliance with a similar Dometic number after gas disconnection by pressing the red flashing triangle for a couple of seconds but there is nothing to press on mine..


View attachment 232022

I have filled in an online enquiry for with Dometic but it was rejected as it did not support the "Article No" that I supplied!!
There is electrical power to the appliance so can I rule out a blown fuse?

Anyone any suggestion before I call out an engineer?

This is the spec of the appliance..

View attachment 232023

I am reluctant to try and get to the burner to blow it clean as it is not very easy access and I can't see what I am doing other than with a reverse image in a mirror which makes my head hurt

When we first got our van, I had a similar problem. I was switching on and off to restart, thinking there was air in the lines. Sat down and read the manual carefully and realised what @Hettie's Crew has just said. Worked first time

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[namwaldog]

Thanks @Makingtrax , I think ours must be an earlier version as the the red flashing triangle is not a button so I cannot press it.

 

[namwaldog]

Still trying to get my head round this problem but discovered this .pdf document that may help both myself and anyone with a Dometic 8 series fridge freezer.
It is an official Dometic Service instructions document and the models covered are included on the first page (shown below).

https://www.4mcculloch.co.uk/images/mediator/559/599719262.pdf

It includes the model I have and has answered a few questions already on the first read through!

 

[namwaldog]

Finally got this problem sorted

After much head scratching and trawling of the internet I eliminated all the other reasons for the failure and came up with a possible fault on the Burner Control Device.

This is a sealed standalone unit on the back of the fridge (see GFA on attached wiring diagram) which takes seven wires in a 8 way plug...

3 for power from the Printed Circuit board
3 from Gas Valve
One earth to Gas Burner
One is vacant

There are two other cables that are have single plug-ins ( and not interchangeable by size - one plug is bigger than the other) that go from the Burner Control Device to the Igniter & Ioniser on the Gas Burner

This Burner Control Device takes power and signal from the Printed Circuit Board and opens the Gas Valve, causes ignition spark at the burner and tests for flame failure at the Gas Burner all in a predetermined sequence .

I obtained the replacement Burner Control Device from www.swordcrowncaravans.com
who are near Seaton in Devon. at a delivered cost of GBP 105. They were about GBP 20 cheaper than anywhere else I could find. I ordered at 11am yesterday and they were delivered by Royal Mail at 11 am today. Sword Crown Caravans recommend you contact them prior to ordering and they will verify with Dometic that it is the correct part for your Fridge based on the Model number on the plate inside your fridge.

To find the Device on the Internet I Googled combinations of "Burner Control Device", "P810", and "Dometic" and selected Images which showed all the images of the Device on the Internet and then looked at the website that had loaded each image.

Wiring Diagram

The Replaced part

Have learned a lot during this repair and gained a lot of satisfaction from sorting it out.

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[Hettie's Crew]

I know this is unrelated to your problem but maybe useful to know, we pitched up a couple of hours ago and had the ‘door open’ alarm going off repeatedly and the blue light flashing, fair spoilt my lunch worrying what it could be.
Turned it off and on repeatedly to no end. After Liz did a bit of internet searching it turns out to be condensation behind the light/door catch. Took it to bits and dried it all out, everything fine again. Going to put some Vaseline on the plug when we can work out what it is in French.

 

[Fletton]

Still trying to get my head round this problem but discovered this .pdf document that may help both myself and anyone with a Dometic 8 series fridge freezer.
It is an official Dometic Service instructions document and the models covered are included on the first page (shown below).

https://www.4mcculloch.co.uk/images/mediator/559/599719262.pdf

View attachment 232815

It includes the model I have and has answered a few questions already on the first read through!

Downloaded and saved to my Knaus folder.... I’ll copy to the resource section on here too

 

[Lofty1]

Ours stopped working on gas l checked all the connections suddenly started clicking again turned the gas on and the fridge caught fire , gas off and fridge replace with a simpler one non electronic

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[tonyidle]

Finally got this problem sorted

After much head scratching and trawling of the internet I eliminated all the other reasons for the failure and came up with a possible fault on the Burner Control Device.

This is a sealed standalone unit on the back of the fridge (see GFA on attached wiring diagram) which takes seven wires in a 8 way plug...

3 for power from the Printed Circuit board
3 from Gas Valve
One earth to Gas Burner
One is vacant

There are two other cables that are have single plug-ins ( and not interchangeable by size - one plug is bigger than the other) that go from the Burner Control Device to the Igniter & Ioniser on the Gas Burner

This Burner Control Device takes power and signal from the Printed Circuit Board and opens the Gas Valve, causes ignition spark at the burner and tests for flame failure at the Gas Burner all in a predetermined sequence .

I obtained the replacement Burner Control Device from www.swordcrowncaravans.com
who are near Seaton in Devon. at a delivered cost of GBP 105. They were about GBP 20 cheaper than anywhere else I could find. I ordered at 11am yesterday and they were delivered by Royal Mail at 11 am today. Sword Crown Caravans recommend you contact them prior to ordering and they will verify with Dometic that it is the correct part for your Fridge based on the Model number on the plate inside your fridge.

To find the Device on the Internet I Googled combinations of "Burner Control Device", "P810", and "Dometic" and selected Images which showed all the images of the Device on the Internet and then looked at the website that had loaded each image.

Wiring Diagram
View attachment 236058


The Replaced part
View attachment 236059

Have learned a lot during this repair and gained a lot of satisfaction from sorting it out.

Nice work and a good outcome. It is always worth trying to sort things yourself .

 

[swiftsteve]

I know I'm resurrecting an old thread, but I would like to thank motorhome fun and in particular namwaldog for this thread.
I had the same problem with my fridge/freezer at the weekend (not on EHU ). After a quick google up popped this thread. I bought the burner control unit, it arrived today. I fitted it in 5 minutes, put the fridge on gas, checked it an hour later and it was cooling beautifully.
I could have took it back to the dealer as it's still under warranty, but we're away again this weekend so I was reluctant. Many thanks again. I love this forum .

 

[Fletton]

I could have took it back to the dealer as it's still under warranty,

Why not ask dealer to refund cost of part ?

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[swiftsteve]

I could do, but I don't want to waste any time on it. I'm just happy I managed to fix it quickly.