Furnace Blower RFI - Suggestions?

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  • Updated 7 months ago
Sorry but the pictures that follow are gruesome and may churn the stomach of even the most stout OM or XYL...

I have a 1.5 yr old Goodman furnace that has an ECM blower motor.  In diagnosing the situation, when at the furnace and watching my waterfall, 10m gets blown out as visualized below (2nd one) the moment the relay flips and blower starts moving.  These aren't birdies they are a flock!





I am in the process of working with installer and mfg but it's not looking promising.

I have found these two articles and am headed down a path of suppressing RFI on the wires to the motor- hoping its there....  Curious if any of you have seen such a signature and have any tips as I hate to stumble around for months to sort this out - although the 10m prop is shot for a year or two more so I guess I have time....

Resolving Furnace and A/C RFI (Radio Frequency Interference) - ARRLwww.arrl.org/files/file/.../Solving%20Furnace%20and%20AC_RFI_KM4LHZ_v9.pdf

https://www.eham.net/articles/32146

Thanks,

-Dave
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Dave - N6XVZ

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Posted 8 months ago

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Mark Aaker K6UFO

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When my new furnace had this problem several years ago, the following steps helped.
The manufacturer had a "RFI kit" available to installers, and it was basically just an 
AC line filter. It helped. I then used a small loop as an antenna "sniffer" as I tried to 
see where the noise was coming from, even taking the front panel off. The motor wires 
were the worst, so I replaced them with a "twisted pair" with a small ferrite at each 
end and the noise was reduced to negligible levels at my antennas.