# Three Flashing Lights



## heruide (Feb 12, 2008)

Went to sleep last night with my Atwood furnace working well but at 3:00 AM I heard the furnace blower come on and the ignition tried three times with out the furnace lighting. This occurred a couple times and I figured out I was out of propane. :smack-head:

Now DW doesn't really like the cold and I really wanted her to wake up to a toasty PUP, so I got dressed and when outside into the freezing cold to switch over to another propane tank. 

However, I learned the hard way that one should not assume that an unused tank (which is covered) is connected. :comfort_:

Also learned the hard way that you should not rush to turn on a propane tank. :bang:

Anyway after a couple trips outside in the cold, I confirmed gas was in the line when I got the stove to work. However, the furnace continued with the same symptoms. Took off the cover and saw the LED flashing light three times. Turned on my lap top (thank goodness for my Air card as I'm in the middle of nowhere with no lan connection) and down load two Atwood manuals. The first technical installation manual had the following codes:

1 Internal Circuit Board Failure Steady on, no flashing
2. Limit switch/Airflow problems 1 flash with 3-second pause
3. Flame Sense Fault 2 flashes with 3-second pause
4. Ignition Lockout Fault 3 flashes with 3-second pause

So I know I have a ignition problem. The second document I downloaded was the service manual and for the ignition is said the following:

As power is applied to the circuit board, the system does the following:

a. timing circuits allows the blower to purge the heat chamber for 15 seconds.

b. current is supplied to the gas valve and causes it to open to high burn. (The controller module activates the low burn operation on the valve.)

c. as the valve opens, the ignition module sends a high voltage spark to the electrode at the burner. The ignition module detects the presence of a flame. If the flame is not sensed after 7 seconds of sparking a signal is sent to the controller module that there is no ignition and shuts off the valve. After another 25 second purge, it will try again. After a third try, the controller will go into “soft” lockout, timing for one hour and the diagnostic LED will flash a code, see chart. After the timed hour, the controller will initiate (3) more tries for ignition. If there is no ignition, the timing sequence begins again.

d. If the system does not ignite and the thermostat is still calling for a heat demand, the blower will run for 90 seconds as a post purge then shut off.

This is exactly what happened to me - Yes after an hour the system tried again and the furnace was back in action. This is the second time I've had this problem and had to wait for some time for the system to reset after starting up without propane. Net I will be buying a automatic change over regulator and never trust the propane gage that told me I had lots of propane. 

Ruide


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## antigua (Dec 17, 2007)

LOL!!! I love to read what you write Ruide. That must have been something. I'm glad the heat came back on. I have an automatic change over on my trailer. But I still use the gauge too just to confirm. I have a couple of them just for that reason.


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## heruide (Feb 12, 2008)

Antigua,

Thanks for the compliment. Did you try the gage with the remote feature? Maybe if the gage was in the camper I would look at it more often... Right now it is outside and I'm inside fat dump and happy ... until 

Ruide


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## antigua (Dec 17, 2007)

No I haven't. Mine is attached to the propane tank. It's not digital at all. I look at the needle it's either pointing to full green, almost empty yellow or uh oh red which is empty. I check it everyday just to keep on top of it.


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## heruide (Feb 12, 2008)

Antigua, Thank you.

Ruide


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## Lester (Feb 3, 2011)

OK, thanks for informative discussion. I had similar problem and just got heater to work by disconnecting the circuit board and reconnecting it. 

I don't want to run out of propane on both tanks. So I usually leave one turned off and when smth doesn't lite, I manually switch and refill the empty tank..

NOW my question for you is: if I turn on both tanks and one runs out, the auto changeover regulator will switch to other tank (assuming it is connected and turned on). How will I know this has happened?


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