Not getting enough humidity in the air

Are you able to fit a bridging wire between W1 and W2 with humidifier wired into either W1 or W2?

Hi,
Sounds like you are not getting the proper voltage to the solenoid valve...
Check for 24v coming off of the transformer...that may be 24vac not vdc...

Then check to see if there is power coming from the humidistat...
unhook the wires to check for the power at the solenoid valve...
check across the two wires...

if there is power the valve is bad and that alone will cost about 90 bucks with shipping...
if there is no power trace back and see where the power stops at...

heatman101

Hope this helps, check and see if humidistat is set to 35% humidity and that bypass damper on humidifier is in the open position or winter position.(humidistat is usually located on cold air return duct near furnace). Next, replace humidifier media pad, remember to replace media pad (filter) annually, you also may want to clean any lime deposit out of humidifier housing with a solution of warm water and white vinegar before installing your new media filter.Remember to turn power off at side of furnace when cleaning humidifier and replacing media. Before installing new media turn power back on to furnace, set humidistat to the on position, turn furnace thermostat above room temp., and inspect humidifier to see if water is running from top,(you may want to have a bucket under humidifier when checking for water), if you see water running, turn power back off to furnace, properly install new media filter, reconnect humidifier cover & set humidistat to 35%. If you do not see water present, check water supply valve to humidifier and make sure its turned on. If water supply valve is open, then check water supply tubing for blockage.And the last things to check is to make sure all registers through out your home are open and not blocked by any objects, also make sure furnace filter is cleaned, if none of this works refer to installation manual to see if humidifier was sized and installed properly, Good luck.

It sounds like you got it...

The solenoid will not open with only 13 volts to it. Jump or apply the full 24-27 volts to the solenoid and see if it clicks and opens and allows water to flow.

If the valve still won't open or pass water, start looking for a plugged inlet solenoid inlet screen or a faulty solenoid valve as well as a faulty humidistat.

if your using an outdoor thermostat then it may not be connected properly or the manual mode resistor wires are touching. these are connected on the humidistat just to the right of the H H terminals

Humidity must be hi enough in the house or Humidistat is not working. Do you any way to check humidity in the house?
If the Humidistat is set as Automatic, try to leave it as Manual.

you need to make sure your humidity level in the house isnt higher then what your humidifier will provide at any givin outdoor temp. this chart is in the owners manual. you cant remove the wires going to the ODS or it will give an error unless you have a resistor to put in its place. Anyway if the humidifier works in test mode according to AA it works so you may have higher humidity than you think, the highest your gonna get is 45% as the temp outside drops it will allow less humidity so it doesnt cause window condinsation (property damage) here is a copy of the chart. the #s on the left are the dial setting
TABLE 2 – % Relative Humidity Guide
Outdoor Temperature (°F)
-10°F 0°F 10°F 20°F 30°F 40°F
1 10% 10% 10% 15% 20% 25%
2 10% 10% 15% 20% 25% 30%
3 10% 15% 20% 25% 30% 35%
4 15% 20% 25% 30% 35% 40%
5 20% 25% 30% 35% 40% 45%
6 25% 30% 35% 40% 45% 45%
7 30% 35% 40% 45% 45% 45%

if it works in the test mode then it should be okay but you can get a humidity gauge from radio shack and set in the house to see how high or low its is. the humidifier is only going to give a max of 45% humidity

If I'm not mistaken, the 600 has a automatic or manual control built in to the same humidistat. The only thing required is the outside air sensor (oas) be mounted outside and wired into the humidistat. Don't forget to remove the "manual" jumper from the humidistat.

i have an aprilaire model 550 im getting no water to the filter but i am getting water to the solenoid