Main Vent Help

Hello,

I've been fidgeting with my steam heat system since I bought my house almost 3 years ago. I recently decided to get a repair man to finish off the rest of the job but after his initial visit I've sent him 3 messages and still haven't received a itemized estimate from him. Because it's starting to get cold (and I want my system to be working correctly) I've decided to see if I can do some of his suggestions myself.

One thing he said was that my main vent was too small. He held his hand to the piping next to the vent and said it took about 10 minutes to warm up from a dead cold (this was the first time my heat had been turned on that season) and that it should take about 2-3 minutes. He suggested replacing my current main valve with a Gorton Size 1. However, when I checked the size of the main vent after he left, it already is Gorton Size 1. Should I size up to a size 2 or could this indicate another problem?

Thank you.