[mpd671]

Doesn't reach set temperature

6 yr old N9MP2 with Honeywell SV9541M Smart Valve

At self induced shut down, flashes 6 and one blinks, which translates as Soft Lockout, Failed to light pilot during 90 Sec trial for ignition, Combustion blower is de-energized, Circulating blower is de-energized after Off delay. After 5 minute delay time, control system will reset and initiate a new ignition sequence.

Prior to relighting, the flash will change to the 3 blinks - Pressure switch open when should be closed.

There is a slight squealing sound from the combustion motor - almost like it needs some oil. I doubt it's running long enough to overolad the motor and trip out.

Where should I start?

[hvac1000]

It is possible the combustion motor is having a problem. The unit depends upon a proper operating conb motor to create the force to prevent a safety control lockout. In other words the pressure switch is not activating because the conbustion blower is not working properly. Just a thought and also check hoses for restrictions and cracks.

[mpd671]

Can I oil the summavabeech?

Getting durned chilly around here, and of course the parts places think today is Sunday - LOL!!

[hvac1000]

You may try that but easy does it since I have no idea if the little motor has oil holes and that means you might have to take it apart. If you do that is a sealed housing and will have to be resealed to work properly. Usually those are just replaced as an assembly.

You might also wiggle the wires on the honeywell dumb valve since they have been known to cause problems also.

[mpd671]

OK, pulled the dust cover off the motor housing, found that there was a plastic fan blade at the end of the spindle that had broken free, so besides no airflow over the motor to cool it, there was also the friction of the hub against the broken fan.

I've put things back together without the little fan blade, and unit runs quite a bit longer before shutting down, but still cycles off before reaching set temperature

[hvac1000]

First things first. Replace the defective part then post back. It is possible that the new part will correct the problem since the combustion blower motor might drag a bit more the longer it runs.

[mpd671]

Just wanted to check in with you, let you know I'm solved and grateful.

Found another test to do, I wired the motor direct to AC, and sure enough it was overheating and shutting itself down - thus the short cycling.

I was able to get a replacement - a story in itself, thanks to International Comfort Products "dealer only" policy on parts - And all is warm and toasty again.

Thanks to you, HVAC1000, and all the moderators that keep us up and running!

[hvac1000]

Glad you got it going.