"succeeds"........"suck seeds ".............................................with chartrock on the road I thought I would chirp in.
Interior Thetford N3185 Fridge Issues
- Thread starter Rogerthatv2
- Start date
Thanks @Drover , I was far too slow to "get" that one. But I do thank you for your "chirp" for dumb galahs like me!! Cheers
Hi Guys,
I'm also having problems with my N3185 igniting on gas. However the problem is intermittent. Most times it tries to ignite, it succeeds. However, occasionally it will fail to ignite. It tries to ignite for ~30 seconds and then gives up and the panel lights begin flashing. It doesn't then try to ignite again until the power is cycled at the control panel. This obviously introduces a reliability issue when the thermostat tries to re-ignite the flame whilst the van is unattended.
It's not an air in gas line issue, as the fridge can run fine on gas for hours (even days) and then fails to re-ignite. Initially I replaced the regulator at the bottle, but the problem remained. More recently I observed what was going on at the rear of the fridge (with the vent removed) when it tries to ignite. Time to ignite ranges from maybe 2 to 20 seconds, and sometimes it fails to ignite altogether (as mentioned above). I noticed the gas solenoid audibly clicking in every time. I removed the burner cover and when introducing an alternate ignition source as soon as it tries to ignite, the burner lights immediately, every time. So this told me the issue lies with the igniter. The igniter always fires, but does not always ignite the gas. So I shined up the electrode and burner with some wet & dry, but the problem remains. The wiring/insulation to the electrode appears fine (no visible arcing to earth other than at the burner). I'm uncertain how to judge what is a strong vs weak spark. Could the electrode be worn even though it looks fine? Could it be the electronics that drives the electrode? There doesn't appear to be any built in method of adjusting the electrode to burner gap - should I bend the electrode to try different gaps? The van is only 3 years old.
Any ideas greatly appreciated. Thanks in advance.
Cheers,
David.
I'm also having problems with my N3185 igniting on gas. However the problem is intermittent. Most times it tries to ignite, it succeeds. However, occasionally it will fail to ignite. It tries to ignite for ~30 seconds and then gives up and the panel lights begin flashing. It doesn't then try to ignite again until the power is cycled at the control panel. This obviously introduces a reliability issue when the thermostat tries to re-ignite the flame whilst the van is unattended.
It's not an air in gas line issue, as the fridge can run fine on gas for hours (even days) and then fails to re-ignite. Initially I replaced the regulator at the bottle, but the problem remained. More recently I observed what was going on at the rear of the fridge (with the vent removed) when it tries to ignite. Time to ignite ranges from maybe 2 to 20 seconds, and sometimes it fails to ignite altogether (as mentioned above). I noticed the gas solenoid audibly clicking in every time. I removed the burner cover and when introducing an alternate ignition source as soon as it tries to ignite, the burner lights immediately, every time. So this told me the issue lies with the igniter. The igniter always fires, but does not always ignite the gas. So I shined up the electrode and burner with some wet & dry, but the problem remains. The wiring/insulation to the electrode appears fine (no visible arcing to earth other than at the burner). I'm uncertain how to judge what is a strong vs weak spark. Could the electrode be worn even though it looks fine? Could it be the electronics that drives the electrode? There doesn't appear to be any built in method of adjusting the electrode to burner gap - should I bend the electrode to try different gaps? The van is only 3 years old.
Any ideas greatly appreciated. Thanks in advance.
Cheers,
David.
Hi,
Definitely do NOT bend the igniter electrode. It is made of very brittle metal and will easily snap if you attempt to bend it.
I tried to bend mine to improve the spark. SNAP! That was a $34 lesson.
The electrode is held in with one screw. You can get a little adjustment by loosening the scew and repositioning the electrode.
The other way is to get a pair of pliers and carefully bend the metal housing where the electrode is screwed in.
Carefully check your warranty. It may be three years. Mine was two years but I think it was increased.
take care
Mike
Definitely do NOT bend the igniter electrode. It is made of very brittle metal and will easily snap if you attempt to bend it.
I tried to bend mine to improve the spark. SNAP! That was a $34 lesson.
The electrode is held in with one screw. You can get a little adjustment by loosening the scew and repositioning the electrode.
The other way is to get a pair of pliers and carefully bend the metal housing where the electrode is screwed in.
Carefully check your warranty. It may be three years. Mine was two years but I think it was increased.
take care
Mike
Have had 2 of these type of problems and in each case it was a cruddy/bad connection................... To start on gas the solenoid will open and allow gas flow, the spark will ignite gas and the thermo couple (probe) will register the heat if it doesn't the solenoid will shut down, the current generated by the probe keeps the gas flowing, I found that the connections at the solenoid from the probe were the problem..............I think the installation manual gives you testing info for the probe if your handy with a multi meter....cobwebs will short the spark as well..............this all happens in a couple of seconds, HWS systems will usually try a few cycles before throwing a fault and I think fridges are the same....
I tested mine with a lighted taper one quick flash of gas then it shut down which showed the signal from the probe was not getting to the solenoid, I had tested the probe with my meter so I knew it works so it had to be a broken wire or bad connection, replaced connectors and all good..........one on a Dometic and one on a Thetford but I think all 3 ways are similar basically.
Oh and the flame is only small like a pilot flame, its not a flame thrower.
I tested mine with a lighted taper one quick flash of gas then it shut down which showed the signal from the probe was not getting to the solenoid, I had tested the probe with my meter so I knew it works so it had to be a broken wire or bad connection, replaced connectors and all good..........one on a Dometic and one on a Thetford but I think all 3 ways are similar basically.
Oh and the flame is only small like a pilot flame, its not a flame thrower.
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Thanks for the replies guys.
@mikerezny on mine there are two screws holding the electrode surround in place within the burner chassis - perhaps some movement is possible but nothing significant I expect. I'll have another look tonight. I might be able to put a shim under one side to tilt it and therefore change the spark gap. Did you have ignition problems similar to mine, and if so did you achieve consistent improved performance after changing the spark gap as per your description? Indeed I do have a 3 year warranty - was just trying to determine if there's a quick fix. Due to the intermittent nature of my issue it's highly likely a service centre will do a quick test and report 'no fault found'. My fridge can run for hours or days (many ignite/extinguish cycles) before there's a problem. Suspect the spark is borderline powerful enough such that sometimes it works and sometimes not.
@Drover I went looking for bad connections but everything seems solid. Agree with your description of the principle of operation. However in my case there's no evidence of problems with the solenoid or probe - it seems to be simply an ignition issue. Observing as it ignites the I've never seen the flame ignite and then extinguish - I understand what you mean here as I've have had this issue with a house oven & had to replace the thermocouple.
Cheers,
David.
@mikerezny on mine there are two screws holding the electrode surround in place within the burner chassis - perhaps some movement is possible but nothing significant I expect. I'll have another look tonight. I might be able to put a shim under one side to tilt it and therefore change the spark gap. Did you have ignition problems similar to mine, and if so did you achieve consistent improved performance after changing the spark gap as per your description? Indeed I do have a 3 year warranty - was just trying to determine if there's a quick fix. Due to the intermittent nature of my issue it's highly likely a service centre will do a quick test and report 'no fault found'. My fridge can run for hours or days (many ignite/extinguish cycles) before there's a problem. Suspect the spark is borderline powerful enough such that sometimes it works and sometimes not.
@Drover I went looking for bad connections but everything seems solid. Agree with your description of the principle of operation. However in my case there's no evidence of problems with the solenoid or probe - it seems to be simply an ignition issue. Observing as it ignites the I've never seen the flame ignite and then extinguish - I understand what you mean here as I've have had this issue with a house oven & had to replace the thermocouple.
Cheers,
David.
Another thing to consider is the thermo-couple, that part that senses the heat from the lit flame. If the igniter sparks okay, then it is generally not the igniter. If it sparks okay and lights the flame but the flame then goes out, it is the thermo-couple. For safety purposes, if there is insufficient heat sustained on the sensor, the gas will cut off and the whole process starts again with the igniter trying to re-light the gas. On those that I have had previous experience with, I found the end of the thermo-couple "carboned" up with some sort of coating. Removed thermo-couple, cleaned up the part that sits permanently in the flame with sandpaper and no more problems. Although I do not have the automatic type like you do, it is necessary for me to hold down the gas line button for about 15 secs after ignition until the thermo-couple has sufficient heat to keep gas line open for flame to keep burning. Only then can I release gas button. @mikerezny has already told you how to adjust the gap between electrode and GOOD earth.
Thanks @Boots in Action. Yes as mentioned above in my case the thermocouple appears fine. Unfortunately cleaning up the electrode and the burner where the spark arcs to has not improved things. I did wonder about the quality of the earth. There is no dedicated earth wire from the burner assembly back to the control board where the HV electronics for the igniter are - it appears to be just relying on the fridge chassis for earth - probably good enough given the high voltage involved?
Cheers,
David.
Cheers,
David.
The fridge turns the gas burner on and off?? My Dometic just stays on constantly ... interesting.
I had initial ignition issues when we bought our van, gas fine, peizo fine, thermo fine but the bugger wouldnt ignite. Like you, it lit with a match no problem. I eventually discovered that the strike point of the peizo spark was vital. Although it seemed to be striking fine, moving it 1mm was enough for it to light fine, as opposed to light rarely ... and visually, im buggered if i could see any other difference
I had initial ignition issues when we bought our van, gas fine, peizo fine, thermo fine but the bugger wouldnt ignite. Like you, it lit with a match no problem. I eventually discovered that the strike point of the peizo spark was vital. Although it seemed to be striking fine, moving it 1mm was enough for it to light fine, as opposed to light rarely ... and visually, im buggered if i could see any other difference
Again @D4DDave, @Crusty181 could have a point about "spark strike point." Watch carefully to see where spark earths to. If you can move the burner a millimeter or two either way, it might improve things for you.
Another way to check if earth is constant and always good would be to do the following:
Take a piece of low resistance insulated wire. At each end connect firmly a small but strong clip (with sharp points on each side of jaw). Connect one end onto a clean and good part of the burner (away from the jets) and the other end to a known and positive earthing point - a good clean and large surface area . See if that improves the ignition at all. If it does not, then you need to look at the thermo-couple again- just because it looks okay, does not mean it is. The coating that forms is the same colour as the metal, but tends to insulate the metal underneath from the heat of the flame. After that, I would be looking at a constant gas flow. Check solenoids. Also if you remove the burner jet that restricts the gas through the small hole,, check to see if is absolutely clean They have been known to block up with debris from the gas line. They usually incorporate a fine mesh filter just before the jet to prevent this. If in doubt, soak in petrol or good carby cleaner and blow dry. Under no circumstances try to poke thin wire etc into jet. Hopefully with these extra ideas completed, it will solve your problem. Because I am running out of ideas and experiences from the past!!!
Hi,
Great!
Now the problem is recorded, this issue will stay under warranty until it is resolved. Regardless of when the three year period ends.
Also, if after reasonable attempts have not fixed the problem, you can demand that the fridge be replaced. Keep track of all dates, phone calls, names etc, and get everything in writing if possible.
take care
Mike
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@mikerezny exactly. Warranty will have actually expired by the time the Thetford agent can fit it in, but as you say, the details are logged now. The agent told me that Thetford wouldn't be finicky about dates anyhow.
@Drover yep, as per my original post, lights immediately every time with a match.
Cheers,
David.
@Drover yep, as per my original post, lights immediately every time with a match.
Cheers,
David.