Author Topic: NOISY 2 STAGE FURNACE  (Read 2199 times)

Offline DANIEL SCOTT

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NOISY 2 STAGE FURNACE
« on: November 16, 2017, 08:40:40 AM »
I have an Aire-Flo 2 STAGE gas furnace and it is quite noisy even when the blower performance is set at its lowest CFM rating and especially when the 2nd stage heat kicks in.
Is there a way in which the 2nd stage can be shut out completely and only run on the 1st stage.
The thermostat is a single stage one.

Offline Admin

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Re: NOISY 2 STAGE FURNACE
« Reply #1 on: November 16, 2017, 09:01:16 AM »
I'm not sure what model of furnace you have.  I attached a picture of the Aire-Flo control board in the furnace.  Just move the jumper from the 5 or 10 minute pins to NONE.  Now the furnace will not stage to high fire, it will continue to run on low fire.

How many BTU's is the furnace and how many square feet is your home?

Quote
Single Stage Thermostat Operation (A80UH2V and 80G2UH-V Models )
The automatic heat staging option allows a single stage thermostat to be used with two stage furnace models (A80UH2V or 80G2UH-V). To activate this option, move the jumper pin (see Figure 31) to desired setting (5 minutes or 10 minutes). The furnace will start on 1st stage heat and stay at 1st stage heat for the duration of the selected time before switching to 2nd stage heat.
W1 on the control board must be connected to W1 on the thermostat.

Offline DANIEL SCOTT

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Re: NOISY 2 STAGE FURNACE
« Reply #2 on: November 16, 2017, 10:43:47 AM »
Thanks for the quick response.
My furnace model is 95AF2UH070V12B and home sq.ft. is approx. 1500.

I will change the automatic heat stage option to NONE as it is now set on 5 mins.

Daniel

P.S.  If I change the pin setting to run only on 1ST STAGE Heat, will this mean that the Btuh will be reduced and the furnace will run longer to heat the house.?

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Re: NOISY 2 STAGE FURNACE
« Reply #3 on: November 16, 2017, 11:11:27 AM »
Yes, the furnace will use 41,000 BTU's instead of 62,000 BTU's.  The run time will be longer which will improve comfort.

At 1500sq ft, that 70,000 BTU furnace is likely oversized.  A new F280 HVAC design would have likely called for a 45,000 BTU furnace.

The 1st stage will use a lower fan speed which hopefully will reduce the noise.

Offline DANIEL SCOTT

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Re: NOISY 2 STAGE FURNACE
« Reply #4 on: November 16, 2017, 12:09:00 PM »
Thanks again.   I will keep checking to see the outcome .

Cheers,

Daniel

p.s  JUST AN UPDATE.   By mistake I gave you the SQ.FT of the foundation outline and not the actual sq. footage of my 2 storey side split which would be 2500 SQ.FT. So in actual fact the furnace size is maybe a little bit oversized.

Offline NoDIY

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Re: NOISY 2 STAGE FURNACE
« Reply #5 on: November 16, 2017, 01:18:55 PM »
if your running low fire only from here on out. keep an eye on you  thermostat set back programs.. i you like a 5C drop over night but like to be warm around breakfast time you may find it takes longer then you want. not this month but once the deep freeze sets in.. just something to consider you may want to tweek your programs on your thermostat

Offline DANIEL SCOTT

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Re: NOISY 2 STAGE FURNACE
« Reply #6 on: November 17, 2017, 08:17:27 AM »
Following on from my original question, the furnace, as you may guess has a variable speed blower motor and at present the furnace taps on the integrated control for the heat mode is set on its lowest heating speed, but I feel that this may still be too high.
Can the variable speed blower motor be adjusted to an even lower speed by myself or would I need a technician to check this out.?

Offline NoDIY

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Re: NOISY 2 STAGE FURNACE
« Reply #7 on: November 17, 2017, 09:29:16 PM »
have a tech come in. your playing around with the design aspect of the system if you start slowing down the fan... you need to maintain proper temperature rise and static pressure..

cant see why on first stage you would find it very noisy unless of course maybe the blower motor is starting to make noise?

Worth a service call for piece of mind. Ensure its operating safely