HELP! Old Boiler assist needed!

[evergreen1985]

Folks,

There is a 1950's Kohler 22" Oil boiler which was converted to gas in my mother-in-laws basement.
The pressure in the boiler is rising extremely high every time the boiler fires.
The only way I have been able to reduce the pressure at all is by manually using the lever on the pressure relief valve.
I did find the water feed valve open (that is loosened) and the bar pointing straight up. I am assuming this allowed a lot of water to build up in the boiler?

The water feed valve looks like this:
http://www.republicsupplyco.com/Pro...=41&HeatingSubCategoryID=429&ProductID=125760

The pressure relief valve looks like this:
http://www.grainger.com/Grainger/WA...48&srccode=cii_9324560&cpncode=26-115170367-2

The pressure entered the danger red zone last night so I shut the whole system down a released some pressure.
What are some of the common causes of this pressure and is there anyway I can fix it?
Do I need a new pressure valve?
Is the boiler too full with water?
What position should the feed valve be in?

ANY help is greatly appreciated!
Thank you!

 

[D_Hailsham]

This is a UK based forum; we do things differently this side of the pond! You will get more appropriate advice if you use a USA based forum such as Heating Help.