sizing a replacement boiler

mjp82

So the other day I'm speaking with a friend who just replaced hide homes steam system with radiant. Now he'd like to sell me the boiler (mid 90's peerless) for $100 as a back up in my rental (1968 something.)

My question stems mostly around BTUs, the the current unit shows output BTUs as 120k his shows 97k.

The current system works well but I know a boiler that old is a bit of a time bomb, so to get this cheap and store would be a nice safety net.

The home has has 3 radiators removed since the original boiler was installed (by the prior owner) which makes me think it may be over sized for the current system. The home it will heat is only a 1300sqft bungalow with8ft ceilings, though it is mostly not insulated. Would this be a suitable replacement boiler or is there a way to measure the system to make the call?

Also if it will work what's the best way to store a used boiler?

nicholas bonham-carter

This post goes through the procedure of sizing a steam boiler correctly:
http://forum.heatinghelp.com/discussion/153320/help-with-radiator-heating-capacity-boiler-sizing-calculations
On the new boiler tag will be a rating for steam square feet, and that is the number which should equal the total of the radiators.
It has everything to do with the radiation capacity (EDR) of your radiators. You may well find that your present boiler is oversized and the spare one is a better fit, costing less to run.
Post some pictures here of these boilers and their piping.--NBC

mjp82

I can get pics of the current old boiler piping, the newer boiler I no longer tied in to anything. I'll get pics of the plate on the new boiler

mjp82

New boiler plate

KC_Jones

Have you done an EDR calculation on your house? That is the only way to know if the boiler is appropriate or not. The boiler plate just tells what the boiler can do, not if it will work in your house.

Fred

The new boiler can deliver 304 Sq. Ft. of steam. Total the EDR of all radiators in your building and see if that matches or is relatively close to 304 sq. ft.

nicholas bonham-carter

Also a picture of the new boiler piping (whatever remains) could show whether it had been piped in such a way as to put excessive strain on the block.
That could explain why it was switched out for a radiant system.--NBC

RobG

I don't know I would risk installing a 20 year old boiler in a rental. Too much in installed cost to risk it lasting a short period of time.