Miller Furnace

[Tim]

I own a 1998 Commodore 55x14 home that is equipped with a Miller (forced hot air) Furnace, Model MGHB056ABFC-09. It is fueled with LP gas. I've only owned the home since December 29, 2003. I use this home only a few nights each week (it is not my primary residence).

During periods when I'm not at the trailer, I lower the thermostat to approx. 60 degrees. I raise the temperature during periods when I use the home. The furnace has worked well, until last night.

When I entered the tailer last night, I turned the thermostat to 70 degrees. The typical sequence for the furnace is to begin with the burner coming on to heat up the heat exchanger. Within a minute or two, the circulating fan comes on to distribute the heated air through the duct work throughout the trailer. Last night, the burner came on as usual. However, when the fan started, it only ran a matter of 5 seconds or so and stopped. About 10 seconds later, the fan attempted to start again, but shut down in the same 5 second time frame. This continued for about 4 minutes until I lowered the thermostat. I raised the thermostat again totry again, but the same process repeated. The fan WOULD NOT STAY ON!

I called a plummer friend (who lives about 100 miles from the trailer). We talked our way through the Miller operating manual. Unfortunately, despite my description of the problem along with the MIller manual as reference, he could not offer any suggestions to correct this malfunction. Before I ended the call with him, I shut off the breaker which supplies power to the furnace. When I turned the breaker back on and tried again, amazingly the furnace returned to normal operation. I kept a clost eye on its operation through the evening and through the night and itI has worked fine since last night.

I'm trying to find out what caused this problem because, as I said earlier, I only use the home a few nights each week and I'm concerned that if this happens again (it is located in Western PA where winters are brutal) while I'm not there, the results could be catastrophic ( frozen pipes, damage to the furnace, fire, etc.).

I had a local HVAC technicial inspect the furnace today. He called this particular problem a "lockup" but he could not detect any malfunctioning components. He said that he could only pinpoint the exact problem by inspecting the system when the "lock-up" occurs (before I turned off the breaker). This HVAC technicial was recommended by one of my new neighbors so I have no knowledge of how much experience he has with this model of Miller furnace.

I'd like to know if anyone has experienced this particular problem. If so, what corrective actions were taken to solve the problem.

Thanks.

Tim

[Tom]

Hi, since this is a intermitent problem, sort of hard to diagnose here in the forum. I would contact a local Miller tech. If its a common problem, they may be able to give advice. Check in your yellow pages, either in Manufactured Homes or could also be listed in the heating and ac listings. Tom

[Eugene]

Hi Tim, it sounds like you lost one leg of your 220v circuit. This is not uncommon in 220 volt circuits. The ignitor box is 115v to 24v so it would light properly. The fan motor is most likely 220 volts. It sounds like when you re-set the breaker, you re-established 220 volts so the fan works properly. I would check the breaker panel and tighten all screws on all the breakers, as well as the high voltage connections on the unit itself. This is a good practice to perform on all electrical connections since heating and cooling will tend to loosen them over time. JUST BE SURE TO TRIP THE MAIN BREAKER SO ALL POWER IS OFF. I hope this helps.

[Marilyn]

Had a similar problem with a new miller furnace on my 2001 home. Turned out, the circuit board was defective.