Removing Old Boiler Mains

Josh Schneider

Thanks everyone for the tips.

Jackchips, I sized my boiler based on advice from other folks who've redone their houses around here, and all the houses of my style are pretty much the same. I'll do a rough heat-loss calculation, but these are old, loose buildings, and I figure there'll have to be some guessing. All of the lines going to existing radiators are 1-inch, and the baseboards are 3/4" copper, so I figure these are plausible sizes for the new mains (1-inch, generally). Since the fittings on new boilers are 1 1/4", I suppose this is also an option. I know that a circulator needs to work against some resistance, and 2 1/2-inch mains designed for a gravity-feed system aren't optimal. Not to mention which, I'm sick of hitting my head on them, as they hang about a foot below the first-floor joists.

Josh Schneider

Removing Old Boiler Mains

Hi. I posted this to a newsgroup and someone sent me here:

I'm getting ready to scrap the old heating system in my 1900
Philadelphia house. It consists of an oil-burning converted coal furnace with an added B&G pump feeding through 2-inch and 2 1/2-inch cast-iron (or steel) mains and returns to 1 inch for cast-iron radiators and 3/4-inch copper for
one room of baseboards. I plan to repipe the mains with 1-inch and/or 3/4-inch copper, with appropriate tees and a couple of zone valves. I've got a Viessmann gas boiler ready to go.

Now my question (but if anyone wants to throw in any other advice, that's fine -- I'm a novice). Is there any way to remove the old mains without demolishing them? I thought I might be able to loosen the threaded fittings once I removed some copper ends, but no dice so far. Propane heat on the
joints appears to make no difference. I've got a metal cutting blade for my circular saw, a 4-inch angle grinder with metal-cutting wheels, and a sawzall, so those are my fall-back options. But I figure someone might want this pipe, so if I can leave it usable, that'd be nice.

Thanks,

Josh Schneider

Philly

Jackchips

Most of the

old fittings were cast iron and it is possible to break them off the pipe using a couple of hammers. You should wear good work gloves, heavy safety goggles and be sure no one is in the area as the pieces can fly off without warning.

Hopefully you have done a heat loss on your house. Your note about changing to 1" or 3/4" pipe raises a red flag that many pros here may question. Pipe sizes should not be guessed at but sized for the load.

Good luck

Steve Whitbeck

The easiest way to remove the old pipes is to put a 10 lbs or larger sledge hammer BEHIND the fittings and then hit the front side of the fittings with a short handle 2 lbs sledge. After a few good wacks the fitting will fall apart.
(wear safty glasses ) also some mud will fly. The pipe may even still be usable - that is if anyone still wants it.

Unknown

Just like Steve and Jack said

If you want to be able to reuse the pipes , make sure you dont bang the fitting too much in one place , it will bend the pipe threads . If I am banging a 2 inch fitting off , I try to hit the part of it that isnt near the threads . Once you hear the banging sound go from high pitch to low , you broke the fitting . Around here black steel pipe is pretty cheap , the fittings are the expensive items . If you get no takers with the pipe , a sawzall is the fastest way to get rid of it . Good luck Josh .

Tony Conner

I've Found The Best Saw...

...to be a hand-held bandsaw. I've got a Milwaukee deep cut (it'll do 4-1/2" material), and it'll just walk through steel (among most other materials) pipe/angle/channel, etc. It won't fit quite everywhere that a sawzall will, though. They also make a standard depth cut. It won't go quite as deep, but it's cheaper.

One of the fabrication shop welders at a customer's plant watched me cut a 1" sch 80 steel pipe with it, and it went through it fast enough that asked (he hadn't seen one of these saws before) "Is that plastic pipe?"