Intermitent Pilot Ignition Problem - Trobleshooting Question

justjohn

I have a gas fired stream heat boiler about 15yrs old with a Honeywell Intermittent Pilot Module S8610U.  The IPM was replaced last season.  It worked completely well for the season.

On start-up this season, things appeared ok (call for heat resulted in spark and pilot and then main burners, good flame, no rollout.), but there are two error codes flashing and alternating for 10+ minutes:  4 flashes and 3 flashes. 

The code tables says:

4 flashes=flame sensed out of sequence.  Recommended action is "if pilot is present replace pilot gas valve", "if pilot not present...." 

The pilot was present immediately when the spark came and stayed lit.  So it seems ... okay.

3 flashes=Recycle flame failed during run.  Recommended Action is "If flame fails to light on next ignition check gas supply, pilot burner, flame sensor, contamination of flame sensor rod, and ground" 

The flame didn't seem to fail during the run.  The pilot was there for the spark and stayed lit as long as I watched it for....more than 10 minutes.  There was a little pause of 3-5 second between pilot and main burners.  The flame sensor looks clean and the ground and all wires are secure.

Some background:  System has the following wired in series: Thermostat, low water level, damper safety, and flame rollout switch.

I let the system heat for 20 minutes and opened water cutoff drain to purge and when the water level dropped, the burners went off.  And more to the point, when I closed the valve and the level came up, the system restarted like normal - meaning the spark came and the pilot lit, and the main burners fired.  Now, the faults were gone.

Not sure of the next step to take.  Any advice?   Replacing the pilot valve seems extreme when it all apears to work okay.  I'm thinking it might just be a lazy pilot valve since it was sitting all summer and perhaps it will lossen up with cycling (some optimism)

Please can provide some insight into what is happening and what I should do, if anything?  Do I have a possessed IPM?   I appreciate your advice.

  

Tim McElwain

It may just be that

on initial start up there was some air in the gas line and it reacted to a lean mix of gas. If it is now working and you recycle it several times and the flash codes do not come back it will probably be okay. I would not change anything without having a professional look at it.

justjohn

going to keep an eye on it and hope for the best.

Tim, Thanks for the response.