colin weston Posted April 7, 2014 Share Posted April 7, 2014 I knew I would be back again soon with another problem! Doing a check on all my systems I found a problem with my Dometic RM 7271 L Adsorption Refrigerator when operating on gas. When switched manually to the gas mode I got a blinking light rather than a steady light. Operating the fridge on mains electric overnight it works fine. However, when in this electric mode and the fridge is down to temperature, if the switch is turned to the gas mode sometimes the light will be steady for some time before going to blinking mode, at other times it will start blinking straight away. Question: If the light is steady is this indicating that the fridge is down to temperature and hence the gas system does not need to activate? Then when the temperature increases the gas system fails to operate and hence the light blinks. The fridge has been OK since 2007 without a service and has been operated on mains electric most of the time. I have had the ventilation covers off to look for any obvious problems such as a loose wire to no avail. It looks a bit dirty behind the fridge and I wonder whether damp has caused an electrical problem. I do not suspect the gas supply as I have full bottles and I have operated the system on gas for extended periods as per the manual to ensure there is no air in the system. Final question: Is it possible to service the fridge in situ or must it be removed? My assessment is that to get to the gas igniter and jet the fridge would need to be removed. I will attach a wiring diagram. Link to comment Share on other sites More sharing options...
Patricia Posted April 7, 2014 Share Posted April 7, 2014 I have a Dometic fridge but I can't tell you the model because my motorhome is back in the UK. Normally it runs of electric or if travelling on 12V (it is one of the automatic ones) but when not on hook-up it takes a lot of effort to get it working on gas for the first time. I have to keep switching it on, then listening for the two clicks, then trying it again if it does not light. Sometimes I have to do this many times before it will stay on properly. Link to comment Share on other sites More sharing options...
lennyhb Posted April 7, 2014 Share Posted April 7, 2014 Serviced my 76 series myself, easy enough to get the burner through the bottom vent, cleaning the flue & baffle was a bit of a pain (it didn't need doing clean as new after 3 years on Autogas). Top of the chimney was about a foot below the top vent and an aluminium baffle across the width of the enclosure that needed to be removed first, if my arms were a foot longer it would have been easy. Sounds like it is losing the gas supply and trying to re-light, these models have what is listed as a temperature probe rather than a thermocouple could be this that is faulty or the a electronic fault on the control PCB. As Mike says a good clean of the gas lines & jet would be a good starting point. Link to comment Share on other sites More sharing options...
Brian Kirby Posted April 7, 2014 Share Posted April 7, 2014 In addition to the above, remove the bottom vent, switch the fridge to gas, and get down by the vent opening to see: a) if you can see/hear the piezo igniter sparking and clicking, and b) whether you can see if the flame has lit. If the igniter ignites the gas, watch to see if it dies a little later on. No clicking may indicate an igniter problem, or just a loose or dirty connection somewhere. Clicking with no flame may be a failed gas valve or connection, or a blocked jet. If the flame is ignited but dies, it may indicate that the thermocouple has failed, or that the regulator is shutting down. Possibly a trip to a Dometic service centre is indicated since after 7 years, and in view of this problem, a general check over would probably be wise. Link to comment Share on other sites More sharing options...
lennyhb Posted April 7, 2014 Share Posted April 7, 2014 Brian Kirby - 2014-04-07 2:06 PM No clicking may indicate an igniter problem, or just a loose or dirty connection somewhere. That reminds me had a similar problem a couple of years ago, light was flashing but no igniter, while tring to work out the wiring gave all the fuses in the Elektroblock a good push, it worked and never went wrong again. Link to comment Share on other sites More sharing options...
colin weston Posted April 7, 2014 Author Share Posted April 7, 2014 Thanks for your responses. I think it is probably the igniter as I dont get any clicking sound when switching to gas. I did have the problem some years ago and by removing the main fridge fuses in the van and replacing them full operation was restored. This time removing and refitting the fridge fuses had no effect. When you refer to the Electroblock Lenny, presumably this is the bank of fuses within the vehicle. There is a small multi-connector on the rear of the fridge but I haven't managed to fathom out the release mechanism yet. I intended to remove and reconnect this to check if there was a poor connection here. Link to comment Share on other sites More sharing options...
lennyhb Posted April 7, 2014 Share Posted April 7, 2014 The Elecktroblock is the charging & 12v distribution unit that Hymer & a lot of other German vans use. Link to comment Share on other sites More sharing options...
BKen1 Posted April 7, 2014 Share Posted April 7, 2014 colin weston - 2014-04-07 4:32 PM Thanks for your responses. I think it is probably the igniter as I dont get any clicking sound when switching to gas. If its not clicking on gas I would check out the connections from the igniter control (marked with White Arrows ) Just give them a firm pull and they will come out . Check for corrosion or dirt on the pin then check at the sparking end(Red Arrows) make sure there is no dirt or rubbish causing a short circuit. It is possible to adjust the gap for the spark so make sure its not to large other wise you wont get a spark(clicking) Also unplug and replug the white muti connector on the igniter unit too make sure theres a good connection. You can also test for 12 volts at the connector in the pic. Brian Link to comment Share on other sites More sharing options...
JonMac46 Posted April 8, 2014 Share Posted April 8, 2014 When we were having problems with ours, the OH held the gas knob down while I lit the jet with a candle lighter. It lit OK and stayed on so we knew the problem was with the sparker, not the flame detector. Link to comment Share on other sites More sharing options...
lennyhb Posted April 8, 2014 Share Posted April 8, 2014 Colin's fridge has full electronic control so that is not possible, life used to be simple no so any more even camper fridges have microprocessors. Link to comment Share on other sites More sharing options...
gwyn Posted April 9, 2014 Share Posted April 9, 2014 If you need a dometic engineer, I don't know how far he travels but Phil Lorriman on 07944682664 came out to our fridge in the late autumn as the fridge died on holiday. He repaired it sorted out one or two other niggles with it and didn't charge a fortune either. Link to comment Share on other sites More sharing options...
colin weston Posted April 16, 2014 Author Share Posted April 16, 2014 Thought I should give you an update. After finding nothing obvious wrong I decided to call in a Dometic approved Engineer. Nearest to me was Martin Beer of Sylmar Services Limited at Market Drayton. After eliminating the ignition unit, gas valve and the electronics board the fault was traced to one of the wiring looms on top of the fridge. As he had pulled out the fridge with some difficulty due to it being a very tight fit he replaced the loom and fitted a new gas jet. Final bill £155.64 for 11/2 hours labour and including parts. No VAT payable as I guess he is not VAT registered. If anyone else needs help his Tel No is 01630 695549 (Mobile 07710 422500) www.sylmarservices.co.uk He also covers Boats and other appliances. Link to comment Share on other sites More sharing options...
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