Gas and Oil Home Heating Furnaces - Should I replace 17 year old Well Mclain gas boiler?

I just purchased a house last summer and just noticed the date on my gas burner for heat that it is almost 17 years old well-mclain 175,000 btu. It worked okay past winter but i was wondering if i should replace it with a new one since its really old. How much more efficient are they now then the one i have? Would I make up for the cost of replacing with more efficient one in couple of years? Thanks in advance..

The most important thing is proper sizing. 175,000 BTU/hr is a lot of heat. Before looking at boilers, do a manual J heat loss calculation. This is where major savings could come in. After you determine the correct size boiler for your house, then you can start to look at equipment.

The most important thing is proper sizing. 175,000 BTU/hr is a lot of heat. Before looking at boilers, do a manual J heat loss calculation. This is where major savings could come in. After you determine the correct size boiler for your house, then you can start to look at equipment.

Thanks Grady..
How do I get info on donig the J heat loss calculation? My house is 2 story with a basement total of around 2500 sqft. and i am in NYC.

One of the best online programs I know of is available from http://hvaccomputer.com.
It costs around $50 for a homeowner & provides tech support if you need it.

i agreen that's a lot of BTU, do you have on demand hot water from the boiler?

I've use the load clac that Grady link you to, and it's a great program. I used on my own place, and my parent's. home.