On Sat, 22 Nov 2014, trader_4 wrote:

How large is the house? I've never been a fan of the bypass type
humidifier. I have the Aprilaire 700 which has it's own fan and
doesn't short circuit the blower air. I would think one possibility
is that the humidifier just doesn't have enough capacity. The fact
that the furnace is two stage, variable blower, might be a factor too.
I would think he might be getting less airflow, air not quite as hot
passing through it, etc.

Yes, how large is the house? How well sealed is it? You may need two. When
I had Aprilaires I had two of them.

You can also improve it a little bit by having the fan run continuously.

Don. www.donwiss.com (e-mail link at home page bottom).