Low-Water Cutoff Auto Feeder Switch problem

JohnA

I have two problems with my low-water cutoff mechanism on a one-pipe steam heating system with a weil mclain boiler:

1. The switch that activates the auto water feeder keeps getting stuck (about once a year), even though I blow out the water every week.

2. After the stuck switch in #1 above was fixed last time (by my oil company), the minimum water level in glass had changed--it was activating the auto feeder when the water was at a higher level in the glass than it had in the past. Normally, the auto feeder activates when about 1/4" of water was visible (minimum water line), but after this repair was done, it was activating when about 2" of water were visible.

Does anyone have any thoughts on the above? Much appreciated.

John