Miller Furnace Shuts Down and blinks 3 times
Posted: Mon Feb 19, 2007 1:43 am
Been having some strange days with my furnace, a Miller MMHA-075AAHR-01, with not staying on. Years ago it went into lockout and the control box was blinking 3 times. I called a professional (?) that pressed the reset button on the upper limit switch and called it a ($) day.
6 years later my problem is back. At first I was thinking upper limit switch is faulty. But when it is fussy it does start properly and runs in full for 30sec to 5 min (varies), then shuts down too soon, blinking 3 times. After a few resets (off then on) it finally stays on long enough to warm up the house by the thermostat. Then it runs properly for a few days or a few weeks. Weather does not seem to be a factor, only the need for heat.
Since it is going completely through the startup/ignition and shutting off/error after being in full operation I am confused to the real cause. I am a vestal mechanic with electrical, electronic, and computer experience. I cannot find a good manual on this unit or anything close.
It is obvious something is telling it to shut down, but what component?
Dave
6 years later my problem is back. At first I was thinking upper limit switch is faulty. But when it is fussy it does start properly and runs in full for 30sec to 5 min (varies), then shuts down too soon, blinking 3 times. After a few resets (off then on) it finally stays on long enough to warm up the house by the thermostat. Then it runs properly for a few days or a few weeks. Weather does not seem to be a factor, only the need for heat.
Since it is going completely through the startup/ignition and shutting off/error after being in full operation I am confused to the real cause. I am a vestal mechanic with electrical, electronic, and computer experience. I cannot find a good manual on this unit or anything close.
It is obvious something is telling it to shut down, but what component?
Dave