[RFI] RFI and furnaces

[Mel Crichton]

Here's a summary of responses to my query on RFI from high-efficiency gas furnaces, many of which use electronic control modules and variable speed (sometimes DC) motors. I chose a Carrier Infinity, 95% efficient unit with variable combustion blower controls, and so far have heard nothing from it, even on 160 meters.

Clean: Carrier Infinity (2 examples),  Lennox G51MP gas furnace/AC, Amana, Rheem (RFI for a few seconds only when the burner fires off), Burnham, Climate-Master Tranquility 20 ground loop heat pump.

RFI-prone - Lennox G71MMP, Trane XR15, Trane (no model mentioned, manufacturer's fix helped a little)

One guy traced his RFI to the new solid state thermostat that came with the hi-efficiency furnace. I can't speak to that, as I kept my old programmable thermostat.

As stated in so many posts on this reflector, your results may differ - case in point, the clean Lennox vs a similar Lennox with problems. Also, some high-efficiency units mentioned may have been 90% or so, and may not have the fancy speed and burner controls.

Suggest using a portable AM radio at an existing installation, if at all possible. And of course, try to get something in writing from the installer, although appliances are not covered under the RFI standards (such as the plethora of "dirty" plasma TVs)

Thanks to all who replied. I chose Carrier because it's made locally (in Indy), but so is Bryant (a Carrier subsidiary, probably the same RFI performance).

Mel KJ9C