I had the same heating system (one pipe steam) and the same age dwelling.
The steam boiler was installed around 1940 as a replacement for a gas/coal
system. Dumped it last year for a new boiler and fhw baseboard.

An hour and a half is a tad to excessive. It should only take less than
fifteen minutes for the air vents to start hissing.

It could be any number of a hundred or so things that could be wrong - pipe
insulation, air vents, main vent, dirty combustion chamber, etc.

http://www.heatinghelp.com. is full of valuable info. You could post your
question on "The Wall".

One thing you should think about doing is have a *steam* heating pro clean
and check out the system.


"Vito Cavallo" wrote in message
...

I have an old 1920's house with a big old rectangle oil furnace. The
system
is steam heat. The furnace is about 4 feet tall, 3 feet wide and 6 feet
long. House is 2 floors (plus finished attic), 1400 sqft.

When my furnace turns on, it takes about 1 1/2 hours before I hear steam
hissing through my radiators and feel heat. I have 9 radiators in my
house.
House is uninsulated, but will be soon.

Is this too long of a time for a furnace to burn before I can feel heat?
What is a normal range before I should get heat? I live in Boston and
went
through 700 gallons of oil last winter ( very cold last year).

I know the system is old and I will weigh the options of furnace
replacement
vs. oil price when I get some feedback.

Thank you.