Hi folks,

What's the most common size radiator pipe?

Thanks!

That's kind of a broad question. Define radiator. ..

Radiators for heating. Like the ones found in old Victorian homes back east.

Smaller radiators were fed with 1 inch. Larger were fed with 1 1/4 or 1 1/2.
The main leaving the boiler was usually 2 inch.
Some of the old gravity systems had 3 inch mains and the branches to the radiators were bigger.

Good to know. Thanks Packy!



Edited 1 times.

The size was dependent on the size of the radiator, and whether it was one pipe or two pipe steam or hot water. Small hot water could be fed by a 1/2" riser, while the same size steam radiator might use 1".

while i agree some smaller radiators could be fed with 1/2 pipe, the question pertained to "Like the ones found in old Victorian homes back east"..
maybe the radiators in Phoenix have smaller feeds but back east they are bigger.

Radiators in Phoenix? You are kidding right? Anyway, I doubt they have "Victorian mansions" in California. I was basing it on Chicago systems with a circulator. Victorian mansions would usually have gravity hot water or one pipe steam systems.

Gravity systems= larger pipe, forced system=smaller pipe.

Victorians in CA:

[en.wikipedia.org]