Ask Experts Questions for FREE Help !
Ask
    DEK3355's Avatar
    DEK3355 Posts: 1, Reputation: 1
    New Member
     
    #1

    Dec 28, 2007, 09:06 AM
    Fan Motor want go off
    I have a Bryant gas sys. @ 20 yrs. Old. When the heat goes off the fan continues to run. If I cut it off on the wall and back on it will continue to run.
    donf's Avatar
    donf Posts: 5,679, Reputation: 582
    Printers & Electronics Expert
     
    #2

    Dec 28, 2007, 09:27 AM
    Most companies build overrides into their designs. For example, you would not want to turn the blower motor on until the heat exchanger was hot enough to release heat into the house, so they may hold off on starting the blower motor until a temperature level is met and then turn the blower motor on.

    You would really have to read the furnace's schematic to see how it actually works. Usually the schematic is with the furnace or attached to the furnace. I'm not a HVAC guy but if a motor does not shut off it is because something did not tell it to.

    Take a hard look at the motor circuits and see if you can see a shutoff timer. If you can find it on the schmatic, then trace backwards to see what conditions have to be made to turn off the motor.

    A Volt/Ohm meter or a clamp on Am Meter would be real handy for you right now, or an experienced HVAC tech. Personally I'd vote for the tech.

    One other quick check would be to make sure no one has changed the setting to have the fan run all the time. Usually this is a switch on the Thermostat. It will usually say, Fan ON --- Auto. Make sure it is set to Auto.
    hvac1000's Avatar
    hvac1000 Posts: 14,540, Reputation: 435
    Heating & Air Conditioning Expert
     
    #3

    Dec 28, 2007, 09:47 AM
    With a 20 year old unit you probably have a fan and limit control mounted to the furnace at the wall area behing the gas valve. Usually this is located to the right or left of the gas valve up near the top of the compartment.

    Fan/limit controls do go out of calibration

    See the sticky notes at the beginning of this board to locate the control.

    Look at this page for the two types of fan controls.

    https://www.askmehelpdesk.com/heatin...s-58313-2.html
    donf's Avatar
    donf Posts: 5,679, Reputation: 582
    Printers & Electronics Expert
     
    #4

    Dec 28, 2007, 10:01 AM
    Hvac,

    How far off were my suggestions. I'm curious and I can always use the education.

    My furnace, oil, was rejected by Noah when he was building the Ark. It was out of date by then. This heap of metal also supplies hot water to the rooms for heating the house.
    hvac1000's Avatar
    hvac1000 Posts: 14,540, Reputation: 435
    Heating & Air Conditioning Expert
     
    #5

    Dec 28, 2007, 10:55 AM
    Your suggestions were good. I usually try all the simple things first. Home owners usually do not have meters and many tools to work with but some of them do and some of them know how to use them.

    Most of the time we are guessing at what is wrong because we are not there.

    Bryant furnaces also has a few different setups for fan control. The one I mentioned is the easiest for a homeowner to find. If his system does not have that style then it could get more difficult.

    The only way we learn in life is practise and that takes some time.
    There are many things in the HVAC biz that I am not good at because my company never worked on the items.

Not your question? Ask your question View similar questions

 

Question Tools Search this Question
Search this Question:

Advanced Search

Add your answer here.


Check out some similar questions!

AC Motor [ 3 Answers ]

Can I Run 5 HP 1440 RPM AC Induction Motor at 0.5Hz. By VFD if I get desired torque and if my current is within limit?

Ok now the motor went out again! [ 1 Answers ]

OK I put the capasitor in. and now it starts on its own. Were is before I had to give it a push but, it runs for a couple hours and goes out. I ran down this last time and the motor was cool as a cucumber. Now what? Thanks... is a 15 year old carrier.

Blower motor going off [ 6 Answers ]

I just replaced the blower motor because the a/c guy said it was bad and was going to charge me $420 to fix it so id id it myself. I got another motor, the old one was 4 spd 960 rpms, and the new one is 3 spd with 1075 rpms, the people said it was okay to do it like that and got a new capacitor as...

GE motor [ 1 Answers ]

I have a GE motor that I believe is from an old washer. It has 5 wires. Black to white is 0 ohms, red to white or red to black is 3.9 ohms, yellow to blue is 2.0 ohms. There appears to be "no" centrifugal switch, so I don't think it's a capacitor start but with all the wires I think it might be a...

AC Motor [ 1 Answers ]

How Do You Rewire a AC Motor that is used on Conveyors?


View more questions Search