Furnace starts and then stops... :(

[bosstone75]

Hello, Thanks for your help!

I have an Infinity ICS - Model 58MVC060
It was installed in 2009 by the previous owner. We took ownership November 2012 and it ran well that winter and the next summer. It's been about a month since we've tried to use it for either heating or cooling. It would appear though that now that we're in heating mode there is a problem.

First thing I noticed was that the house was not getting warming to the the temperature set on the thermostat. So, after a day of this, I went and checked the air output from the vents. There was none. Then I went down and listened to the furnace. There was no noise at all. I pulled off the cover and noticed a flashing light (not knowing it was the status light or what to do with it, I knew it couldn't be good). I then used the troubleshooting guide in the manual to shut the power and the control switch to the off position and then turned them both back on. Here's what happened.
- The blower motor started (I was so excited and thought I fixed it)
- The gas lit and I could see the flame through the window
- The status light went solid
- I quickly ran upstairs to check the air flow from the vents... none.
- I went back downstairs and noticed that the furnace was off and the status light was blinking again. So I did the restart again.
- This time I stayed downstairs and watched the whole process (and learned a bit about status codes). Blower motor starts, flame starts, then after about 2 minutes, the blower motor starts to wind down and the whole system shuts down. I learned that the status code that was flashing was 41 - Blower Motor Fault. The system started to run again. Same thing. It all starts up and then it all shuts down and the status code that displays is 15.

My friend says I should sand the temperature probe.

Thoughts?

Thanks again!

[HayZee518]

heat unit

check the motor to see if it has oil holes on the end bells. if it does, put a few drops of a light machine oil into each oil hole. if there are no oil holes, then your motor may have ball bearings which are not oillable and need to be replaced.
do you have any way to check the amperage draw of the motor at each speed, usually a clamp around ammeter is used.
Lowes or Home Depot sells a relatively cheap one made by the IDEAL Co.
Next thing to look at is watch the flame on the pilot. If after two minutes it goes out, then your flamerod circuitry is locking out the fans and burner.
check for busted wires at the flamerod or loose wires.
pictures if you can get them will help as will a schematic diagram.

[bosstone75]

As I was rooting around through my documentation on the house (which we recently bought), I discovered that the previous owners purchased an extended warranty that is extended to me, so... I called in the pros.

Thanks for your post and I'll update this to let you know what the service technician does.

[HayZee518]

furnace

I should have looked at the site before opening my "mouth." your system does not use a pilot but a hot surface igniter. it does use a flamerod detector. cleaning it up with sandpaper isn't going to do much good because the instant the flame comes on, any cleaning you did will be covered with soot again.
the flamerod functions by reacting to the ionized air within the flame path.

[bosstone75]

Fixed

It ended up being the control module on the blower motor. We removed that and put a new one on and it's a good as new!

Thanks for your help!