Dometic classic, only 1 spark, won’t fire

[Krak]

Not sure of the model number , but we only have access to propane so we can’t test the AC on our fridge .   Normal operation, you turn it on and it will fire the igniter up to five times and then break for awhile before repeating .    Currently it only fires once, doesnt lite and then won’t attempt to lite again .   Any suggestions? 

Edited June 16, 2020 by Krak

[RWeigant]

You may have a bad board. If you decide to buy another, go to https://www.dinosaurelectronics.com/Ignitor_boards.htm They are the best, not like Dometic junk. They have boards for everything. Made in USA

[oldjohnt]

Same as you stated, most I've had the ignitor tip will spark/fire several times before it times out. Most have the HV coil/transformer located right on the main control circuit board while a few have a separate HV Ignitor module. I agree with RW the problem could be the control circuit board as that's what controls the HV sparks, but I've had far more Ignitor Tip problems then bad circuit boards. For no more then it takes you might examine the Ignitor Tip for hairline cracks, carbon traces and correct gap (fairly critical) and especially look for carbon or soot in the burner and ignitor tip area. CLEAN THAT ALL OUT !!! Another problem may be rust or corrosion or a loose connection or a faulty resistive ground. Check the sheet metal screws and mountings and all electrical connections while you're in there. Even a loose, dirty or corroded connection from the cable to your board can be problematic. Once a buddys acted that way and the burner and ignitor tip area was full of soot. I assume you have adequate gas and pressure ??

PS Low voltage can cause weird problems, yours okay ?? Does it matter if you're plugged to shore power and a good converter/charger has your batteries adequately charged ?? 

John T

Edited June 16, 2020 by oldjohnt

[Kirk W]

I would use a vacuum applied to the burner area first, just to be sure that there isn't some material or bug nest that is preventing the propane lighting. While it is true that it could be the control circuit board, which board is the problem in such case depends on Dometic model that you have. If you look on the side wall of the refrigerator, just inside of the door you should find a plate that will have both the model number and the serial number. Without that information, we are just guessing about what to suggest. 

Am I correct in assuming that your water heater and your stove top both light and work as expected? Low propane pressure could also cause the problem that you have. 

[Krak]

Yes my mistake, definitely should have gotten the model # , will do next time ( 2 hours away ) .   I did give everything a pretty thorough clean.  Battery is 12.3V and propane works on stove, although I’m not sure that equates to adequate gas pressure.  
 

I didn’t look closely at the igniter for hairline crack, and don’t think this one is adjustable for gap.   We have no access to AC as fridge is in a cabin off grid and without a generator .  
 

I don’t smell any propane while I’m waiting for it to lite, is that normal ? 

[oldjohnt]

4 hours ago, Krak said:

 Battery is 12.3V

Thanks for the new info. A full charged lead acid battery at rest and stabilized should be around 12.61 volts at 67 degrees...While 12.3 volts is around 75% charged and should suffice, you might try plugging to shore power when a good working converter/charger raises the voltage just to see what happens.. HOWEVER with no electricity or a generator as you stated, take the battery out and connect it to a good battery charger (get at rest and stabilized voltage back up to near 12.6) and replace it and see what happens !!!!!!!!!!!!!!!!!!!  Or maybe try to use jumper cables to the battery and see if that helps ?????????????

NOTE your voltage reading may not be very accurate IF THE BATTERY VOLTAGE IS LOW that can cause all sorts of problems INCLUDING faulty circuit board (which controls ignition) operation MAYBE YOUR PROBLEM IS ONLY A WEAK BATERY !!!!!!!!!!!!!!!!! 

 

"I didn’t look closely at the igniter for hairline crack, and don’t think this one is adjustable for gap"

 

Just see if there's a bunch of carbon or soot in the burner and ignitor area (if so clean it out) which can cause a problem. If not a carbon trace or hairline crack can cause an ignitor problem which you can later check if necessary.

 

4 hours ago, Krak said:

I don’t smell any propane while I’m waiting for it to lite, is that normal

  Typically if all is working you don't smell propane during the ignition process, especially if the gas valve is closing right away when there's no flame start up. If the gas valve is held open a longer time and there are multiple HV sparks yet she fails to light after multiple attempts, that's when one may smell LP.  

  Without any manual or more detailed info I'm back to my "guesses" (NO warranty, just my best effort to help) if its NOT any soot or carbon issue, the problem could be LOW BATTERY VOLTAGE  Or the control circuit board,,,,,,,,,,,,Or the HV Ignitor Coil/Transformer if its separate from the board,,,,,,,,,,,Or the ignitor tip assembly which includes the tip itself, the HV cable from board to tip and all its connections,,,,,,,,,,Or a loose or resisitve ground or other wiring connection. Insure any sheet metal mounting screws in the burner area are tight with no obvious rust where components mate up. You might check any cable to the circuit board connectors as a voltage drop there can cause problems (remove clean and re attach).

NOTE a manual will have Troubleshooting Tips which you can follow and hopefully find the problem, however the items I mentioned are typical in many cases so they may provide a start until you get a manual. While the problem may well be the board, I like to try easy simple checks first including cables and connections and grounds and mountings and for low voltage then the ignitor tip assembly in hopes you find a CHEAPER CURE then a board which is more expensive. I've replaced a ton of boards over the years with one from Dinosaur Electronics which worked great no problems.   

FIRST GET THE BATTERY FULLY CHARGED AND SEE IF THAT CURES YOUR PROBLEM

John T

[Kirk W]

5 hours ago, Krak said:

I don’t smell any propane while I’m waiting for it to lite, is that normal ? 

In most cases you can't detect any odor of propane in a refrigerator.  If this refrigerator is like those used in an RV, the propane supply is very small and much like a pilot light so it takes a long time for enough propane to come out for you to smell it and the refrigerator will have a limit of how many times it will try, after which the propane is turned off for safety reasons. While a cracked ceramic of the igniter could cause the problem it is an issue that I have only seen one time in an RV refrigerator over the 40 years that I have owned and worked on them. 

What you could do is to try lighting it with one of the barbecue lighters by holding a lighted one there as the refrigerator is turned on a by a helper.  You are correct that the stove top might burn with a lower than normal gas pressure, but if it seems to be the same as in the past that is at least a hint. 

                                     

The RV refrigerators are designed to operate down to 10,5V but a great deal depends on how you measured that voltage and if it was taken under load as a bad battery can present a voltage when not under load and then drop significantly as soon as any load is supplied. Since your dealing with a cabin and not an RV, what type of battery are we dealing with? If you have one of the automotive style batteries that can be easily removed, take it with you next trip and have it load tested at a local battery shop as they will do that free of charge. In this case you could also bring a known good and fully charged battery to the cabin for use with the refrigerator. Are we correct to believe that the refrigerator was working properly when you left from one visit and then failed to work when you returned and didn't fail while in use? Are the indicator lights on the front panel showing properly as they do when things work correctly? 

Since you are off grid, do you have a solar system and battery bank, and if so, do other electric appliances work properly? 

 

[Krak]

It’s a deep cycle battery and yes I definitely did not measure it under load .   The lights come on and function as expected .   I charged this battery on a solar panel,  but we don’t use that for anything else .   Stove is from the 70s, just straight propane .   I’m new to this , taking over for the father inlaw who’s not able to help or advise anymore . 
 

will get some more clues after this coming weekend .  Many thanks everyone !!!  

[oldjohnt]

18 hours ago, Krak said:

It’s a deep cycle battery and yes I definitely did not measure it under load

Krak, You're Welcome and thanks for the update.

  The thing is while the voltage reading alone at rest and stabilized provides an indication of the State of Charge (SOC), that's NOT a full representation of the batteries energy storage and delivery capacity when under a load, it takes an actual Load Test to tell the whole story. If your reading of 12.3 Volts is accurate ??? while in theory that represents a 75% charge, unless the battery is near total shot, since it doesn't take very much current to power the fridge and ignite the flame, Id expect it to still function in the 12.3 (or even much lower provided load capacity is still adequate) volt range no problem. With a good battery having sufficient storage and delivery capacity, I've seen far lower voltage then 12.3 prove functional.  Still, in 49 years of RV ownership, I've seen low voltage or a weak battery cause problems, so it doesn't hurt to check it out. A good charge and Load Test is cheap n easy and there's a chance that alone could be the problem even if slim. 

 If that's NOT the problem, then I'm back to my "guesses" above, absent any information. While this may or may not be what an actual manual for your fridge suggests, its fairly typical of the many fridges I've owned and repaired over the years, so take it with a grain of salt until you get more accurate information.  For your convenience I have copied and pasted my tips above, hope this helps.

       "I agree with RW the problem could be the control circuit board as that's what controls the HV sparks, but I've had far more Ignitor Tip problems then bad circuit boards. For no more then it takes you might examine the Ignitor Tip for hairline cracks, carbon traces and correct gap (fairly critical) and especially look for carbon or soot in the burner and ignitor tip area. CLEAN THAT ALL OUT !!! Another problem may be rust or corrosion or a loose connection or a faulty resistive ground. Check the sheet metal screws and mountings and all electrical connections while you're in there. Even a loose, dirty or corroded connection from the cable to your board can be problematic  (remove clean and re attach)."

PS If Murphys Law applies (often it does) since a circuit board is more expensive then an Ignitor or simple cleaning and re grounding etc connection or low voltage problem, and since the board is what controls the HV sparking (one versus several) the LAW says the board is your likely problem grrrrrrrrrrr lol but try cheap simple fixes first............

     There ya go let us know what you find. I'm sure I missed other possible problems which the other fine gents can add...Hey this is plenty to chew on for now lol 

  John T

Edited June 18, 2020 by oldjohnt

[Lafitte]

New Dinosaur board time.....