Gas Tankless Water Heaters FAQ

Greentherm 9000 Models
It seems to take a long time to get hot water at my fixtures. Is this normal?
Is there any regular maintenance that should be carried out on the Greentherm 9000 Water Heaters?
Can Greentherm 9000 models that include Wifi connectivity be used on all types of wireless network?
What is "Auto Tuning", and when should I use it?
I'm seeing CF, C1, C2, or CE codes. What should I check?
My air intake entry is allowing dust, pollen, debris and insects to be pulled into the water heater, what can I do to prevent damage?
I have my Greentherm 9000 unit installed in a domestic hot water recirculation application. Can I select when the hot water recirculates?