Cast iron water heating system question....

tecsol1

Looking for some knowledgeable thoughts on a house I just bought. The system is an old water heat, not steam. There are a number of broken cast iron radiators and no information for what happened, all utilities have been turned off, at least now, so no knowing what happened. My guess is frozen system and the cast iron burst on about half of them, no seeming pipe related damage, so far.

Any thoughts guys???

TIA

EBEBRATT-Ed

Since you have already bought it you need to start pressure testing the system to find out what's good and what is bad.

Do not test with air, a cracked radiator can turn into flying shrapnel.

Depends how bad it is what your approach will be. I am sure the boiler is probably shot.

A couple of cast iron radiators can be replaced. If the piping is shot pex would probably be the best replacement with manifolds.

Depends how much of the system is shot

Alan (California Radiant) Forbes

Did you get a home warranty policy when you purchased your house?

I hope you aren't living there yet just when it's getting cold.

tecsol1

Thanks folks! The house was bought from a bank, as is. Is water pressure testing the best way? I was considering 10 psi air pressure testing till I saw this reply!!!!!

Best thoughts moving forward for testing? Have worked on hydronic systems before but all with finned copper tube systems, not cast iron radiator systems.

JUGHNE

You could isolate all the obvious cracked rads.
Valve off or cap both pipes.
Start fill in basement slowly.
Boiler may be cracked.

Any pictures of basement piping?
Where is this located? Some basements may not freeze in the winter.

Solid_Fuel_Man

Pretty much any system I've seen with one cracked (frozen) rad has every one frozen in that floor. Sometimes the first floor will stay warmer due to heat from the basement and will not have cracked rads. But my 100% experience with freeze ups is top ones freeze first, then the next floor down, then the boiler last. 

If the boiler froze and split first then a rad or several could have drained and be ok, but I haven't seen that happen. 

Personally, I test with air. 10 psi or less to find splits. Dont go higher with air. If you test with water, there will still be air in the system and the stored kinetic energy is still there, so I think it's a moot point. Just keep the pressure low. All the splits will be gaping holes most likely so no pressure will build. 

Is it small diameter pipe like copper or threaded, or large diameter (1.5 or bigger) that would be a gravity water system. 

hot_rod

A water test could cause a bit more damage to flooring, etc. You would need to watch each radiator as the water in the system rises. I suspect more than one are cracked, possibly some fittings also.