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  1. #1

    Blower speed selections for heat, cool and continuous fan.

    Hi everyone.
    Thank you for answering my return air and static pressure questions in another thread. I have one other question for yall.
    I will try and give you a quick overview of our situation.
    This spring we bought a 7 y.o. 2600 sq. ft. L shaped ranch with a full basement in se lower Illinois. It has a Heil 125k btu, DC90 furnace with AC. Im am not sure what brand the AC is. This is our first does it get cold in Illinois.
    We had a local company come out to do the furnace service. The company came very well recomended by a couple neighbors. From what I posted in the other thread it looks like the guy did a great job. He left me with a lot of documentation on the readings he took and made some adjustments that he said should have been made by the company who serviced it last.
    I asked if the serviceman had any advice for our first winter here. He suggested that we run the furnace fan continually. He said we would be more comfortable and it would help stabilize the temperature in a cold bedroom that is at the end of the house. (it helped a lot)
    At first he turned the thermostat fan to on. He said I wouldnt be happy with that because it had the fan blowing on high. He went back down to the furnace and changed a couple wires so the fan runs slower. The thermostat fan is still set to auto but the fan is running. He has a note on the paperwork that he has the "Continuous Fan Speed" set at "medhi"
    My question is can the fan speed be set to a lower speed? It is noisy and a breezy from the floor registers.
    I called the company and they said my furnace only has 4 speeds and that the low speed is already being used by the AC and he can not set it so both the "Continuous Fan" and AC, both use Low speed.
    Does anyone know if this can be changed?
    Should I call a "Heil" only serviceman to come out?
    The electronic board that he changed the wires on says Honeywell. Should it be a Heil?

  2. #2


    The company came back out to the house to install a new setback thermostat they suggested I buy. This is our first winter up here and they told us the new thermostat will pay for itself in a month. They sent a different serviceman than before.
    While this serviceman was here, I asked him about lowering the continous fan speed.
    He went down and looked at the wiring and in 5 minutes he did what the other serviceman said he couldnt do. He said the continous fan should only be run on low blower speed, not medium low like it was currently set. He said he could install a "jumper wire" to the cool terminal and continous fan terminal so they both would use the blowers low speed. From what I saw him do, he cut a red wire, added a new wire with a terminal, crimped them together and plugged the two terminals into the board. The new wire looks smaller than the original wire. I asked and he said it would be fine. He said the smaller wire is connected to the continous fan terminal and doesnt draw as much "amperage"

    After sleeping on this, I am a little concerned. Does anyone think this setup will cause me any future problems?

  3. #3
    Join Date
    Dec 2007
    Usually the cooling speed is set to high. I don't think there is problem with what the second guy did. Honeywell makes a lot of circuit boards for a lot of different companys.

  4. #4
    Quote Originally Posted by mikesands View Post
    Usually the cooling speed is set to high. I don't think there is problem with what the second guy did. Honeywell makes a lot of circuit boards for a lot of different companys.

    Thank you for your reply.
    The same company came out earlier this year to do the AC service. We complained because the house was humid when the AC was on and it was very uncomfortable.
    The serviceman said that the blower speed for the AC was set at high from the factory. He changed the blower speed to low.
    On the receipt he hand wrote a note "3.5 ton AC" should be 1400 cfm changed fan speed to low"

    If you think it is ok, I wont worry about it. It just seemed like the wire he added was quite a bit smaller than the original wire and I dont want to have a problem when we turn on the AC.

  5. #5
    Join Date
    Dec 2007
    Was the actual wire smaller or did it just have less insulation on it ? Someimes two of the same size wires can have two different thicknesses of insulation on them.

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