Replies

1. 
   Tim_Rice | Feb 28, 2002 04:22pm | #1

   *
   In most furnaces and heat pumps, the various devices are started and stopped by relays mounted in the unit. The blower is not usually on a separate breaker. If it is a thermal overload or a "breaker", being slightly warm to the touch doesn't necessarily mean anything bad, too hot to touch is different. If it is a relay, being warmer than the surrounding air could indicate that its going bad. If a breaker tripped, it would not start back up. A bad relay will sometimes "let go" and then restart the motor.

   Questions: make model and age of the unit? how often does this happen? Do you ever hear "clicking" from the unit when it happens? Does it happen only after its been running continuously for a while?

   Best advice is to have a service call, and tell what's going on.

1. 
   wildone_ | Feb 28, 2002 05:14pm | #2

   *Thanks for your interest. Unit is about 6 years old and is a Lennox B24 series (buider grade). Regarding blower circuit protection, what I meant to say is that their are two circuits for the heating coils. Power for the blower is split off one of these circuits inside the unit. The significance to me was that the breaker for this circuit was warm to the touch. I assumed the breaker would be a no resistance device and not build up any heat. The problem seems to occur randomly every two-three minutes and after the unit has run for awhile. Pressed my ear against the furnace and could not hear a clicking noise. While at the furnace you can hear a thumping every so often it can be felt though the sheet metal. Cannot hear a difference in air volume at the furnace so am not sure if the thumping and "hiccuping" is the same. I have been very unhappy with the service support I have received on this unit from problems discovered after installation and subsequent repair. Did the last diagnostics/repair myself. I am not sure how to identify a good service contractor for Lennox in my rural area. So here I am worried about a potential failure in below freezing weather.

1. 
   Tim_Rice | Feb 28, 2002 10:09pm | #3

   *Modern, common breakers work in two ways. First, as the current approaches the breaker rating, it heats up. It is not a "no resistance device". As the heat reaches a certain level, a bimetalic strip in the device trips it. Second, if there is a large overcurrent, a coil in the device creates a magnetic field and "pulls" on the trip arm, and trips the device. In either case, manual reset is required.Watch your HP with the cover off and verify that the blower is actually stopping and something else is not causing the noise changes. If you can verify the motor is stopping or can verify at least that the current/voltage to the motor is being temporarily lost. Shutoff the power, trace back from the motor to the relay and look at it. You'll prabably see worn contacts, maybe some arc marks/charring. Somewhere on it will be ratings, or makeand model number and get a replacement.If you do not have the equipment or the comfort level to do these things, find some help. This is basic electrical troubleshooting and any competent electrician should be able to help/do this. No need to go with the Lennox guy if he not good to deal with.

2. 
   TimC123 | Jun 14, 2020 06:14pm | #4

   Hello,
   I have an old GE heater/blower and Armstrong A/C unit system. The A/C unit seems to cool good. However, lately I've been hearing some hiccups on the blower while running. You can hear the sound of the blower kind of slows down a little (as if it going to stop), but then it picks up again and continues normal. It happens sometime during the first few minutes after it starts. Then after a while it kinda stops doing it. But not every time though. I tried to sound tape it. But when I do, it doesn’t do it or I does it one last time. Then I hear again. But then, by the time I get my cellphone to tape it, I kind of get to the end of it (hear attached). It puzzles me. Do you know what might cause it to do that? Thanks, Tim.