Boiler fills with water

[scottbeau]

I have a penco steam Boiler ( GAS) The water level fills too high causing the pipes and radiators to bang loudy when the heat starts. If I drain the water It seems fine . There is a valve on the top and one on the bottom of the site glass what do these do ? Should they be open,closed or what ? The only place I see water feeding in ,is from the hot water heater , but that is controlled by a manual valve .
Any suggestions.

[Ed Imeduc]

When was the last time you cleaned out the auto fill there on the boiler. If you have one.You can have yuck in it that lets it over fill The valves should be open so you can see the water level. If you have only a manual valve is it leaking water into the boiler?

ED ;)