Its a Ideal Mexico Super 2 rs125
Everything works great, just that I have to bleed the system regularly.
Thanks for the boiler info; you must have an extremely large or very old house if you need one that size!
It sounds as if the air problem was there before you purchased the house as combined feed and vents are often used in an attempt to solve the problem.
Ideal say that you must have an overheat thermostat if a combined fed and vent is used.