Removing 25-Year-Old Vent Stack

I am removing and subsequently reinstalling my baseboard boiler (I am replacing the pedestal). It is 25 years old. The following image shows its current location:

http://pipsisiwah.home.bresnan.net/images/boiler1.jpg

The installation has an expansion tank at the rear and behind the vent stack. All the connections between the tank and the boiler are rusted solidly together, so the tank will have to come out attached to the boiler. The vent stack is in the way. Please see the following image:

http://pipsisiwah.home.bresnan.net/images/boiler8.jpg

No play exists between the vent stack components, probably because the connections are corroded together.

Will I have to cut the stack away and then replace the parts or is there some way I can separate them without destroying them???

 

Are you sure there aren't sheet-metal screws holding the different pieces of smoke pipe together? I think that I see them in your pictures.

Also, it looks as if you have copper piping soldered in the picture where you detail the "frozen" piping.

 

What about putting in an efficient boiler and indirect tank as well? That would make the venting far simpler.

 

I will cut and move the copper piping you see out of the way.

Yes, there are some sheet metal screws, but I removed them after taking the pictures and none of the parts would budge. I think they are corroded together and I would like to salvage them. I'll try a bit of Liquid Wrench and see if that works.

No money at this time for a new boiler. I'm just replacing the pedestal and the water heater.

By the way, what is an "indirect tank"? Expansion tank? One that is mounted elsewhere? If that's what you mean, I'd like that, but not sure what kind of piping I must use - galvanized water pipe? Steel-braided hose? Copper pipe?

Can you elaborate a bit?

 

Well, I pulled a Popeye and was able to remove the expansion tank and leave the vent stack intact.

The Burnham Model 234C gas boiler must weigh a ton! I can barely budge it. Any of you out there have an idea how much it weighs? Couldn't find any info on the website, nor in the manual pdf. Burnham is shut down for the weekend.

If I knew about what that thing weighs I might be able to oink it down by myself (pedestal is about 20 inches high).

 

Indirect as in indirect fired water heater. It's a water heater that with dedicated passages for the boiler water to heat up the domestic water. With a mod-con boiler you'd find no more fuel efficient way to way heat your water unless your electric is absolutely dirt cheap.

With an indirect you don't have any flue where heat leaks out of it.