Product review (5 stars): Worked on Honeywell HE220A
In my rush to install my HE220A bypass humidifier i forgot to install the transformer and fried the supplied solenoid valve.  An OEM valve was about $10 more.  I ordered this one and was able to install it.  The only difference is that the mounting bracket is on the opposite end.  This meant the outlet feed didn't line up with the hole for the rubber water line and the fitting had to be angled slighty to keep the rubber tube from pinching closed, I also had to salvage the fittings from the old solenoid to match up with the tubing used on the HE220A.

Once I actually took the time to ensure everything was installed properly, the solenoid worked perfectly even in this application.