I have a new Dave Lennox Signature Collection SL18XC1 AC/Furnace. Shortly after it was install I discovered the thermostat was changing programs when I was using my HF rigs. I finally placed toroids on the line going to the back on the thermostat which doesn't seem to help. I was running 400 watts which I've lowered to 200 watts voice. It now does it less often, but still happens. My previous
Lennox about 8 years old which I replaced never had the issue.
Please let me know if you help as I haven't contacted the installer company.
73
Wade w7ute