noise in furnace/ hi and low

[captbanjo]

We have noticed that after we run our heat, there is a fairly low but audible sound coming from the area below our kitchen counter (we have a 3400RL) as if steam is escaping. Does anybody know if this is considered normal? Also, we can only run one speed, apparently high, for heat. There is a high/low switch but it only affects the ac. Anyone chime in on that?

[DrivesBGM]

Can't help you with the noise you are hearing but the fan speed as well as "auto" vs. "manual" setting are for the AC only. The heater fan is one speed and is separate from the air conditioner fan.

Craig

[Montana Sky]

Wayne,
Heater only has one speed on my 3400RL as well. I have been listening for the noise your are talking about and the only thing I could hear that would come close to what you are talking about is when my hot water heater kicks on while using propane. It sounds exactly what you are saying. I am not sure if this is what you are hearing, but thought it might help.