Humidifiers and Dehumidifiers - Aprilaire 600 not working, water not flowing, any help is appreciated

Hi,
I bought my house this summer with an Aprilaire 600 whole house humidifier. During inspection, the inspector found the humidifier did not work, so the owner had a contractor to come and fix it (I have receipt). The contractor replaced the humidistat (even though the inspection report suggested the solenoid valve was broken).

Now I am living in the house and want some relief from the forced hot air dryness, but I can't get the humidifier to work. The humidistat is brand new (matches Aprilaire 600A control panel), has power when furnace runs, detects humidity, and is on manual setting. However there is just no water coming through the solenoid valve. I confirmed there is water coming through the saddle valve.

I put the humidistat on test mode and the water still does not flow through the solenoid valve. So I ordered a solenoid valve replacement, and installed it, but water still doesn't flow through on test mode NOR operating mode. The Humdifier On light is on (then blinks) during test mode AND is on during operating mode (when RH is low enough).

What else am I missing that causes the water to not flow? What else can I try in order to trouble shoot?

Is the humidifier wired to the H/H at the humidistat?

Is anything wired to W/G and Cf?

Is mode switch set to "A"?

my light comes on mine (the bottom light) when you hit test mode to confirm that its "running", The model 600A also turns off after test mode after 60 seconds. Aprilaire has .pdf manuals of their products on their website if you never got one.

Is the humidifier wired to the H/H at the humidistat?

Is anything wired to W/G and Cf?

Is mode switch set to "A"?

I'll check on these tonight. I know for sure the W/G and Cf is wired to the R and C (which is wired from the furnace), it's a setup that I couldn't find a exact diagram to match in the installation manual.

my light comes on mine (the bottom light) when you hit test mode to confirm that its "running", The model 600A also turns off after test mode after 60 seconds. Aprilaire has .pdf manuals of their products on their website if you never got one.

I do have all the manuals, the previous owner was very good about keeping them. Nothing happens, in terms of water flow, after entering the test mode, the bottom light does come on, but starts blinking after a couple of seconds.

Thanks for the help!

I turned the mode switch to A mode (it was on B) and it worked like a charm! What's B mode? What's A mode?

I honeslty don't know... I never been around it to see for myself, other than what the manual shows.