1925 hot-water system; rust in pipes

ALH_4

I dont see any reason why vertical pipes should rust more than horizontal ones. My guess is that there has been a hidden long term leak of some sort and makeup water has introduced enough oxygen to rust the pipes from the inside out. Get the system water tight and you may not have any more problems with leaks for a very long time. Shut off the makeup water and see how quickly the pressure drops. Is this sytem all cast iron radiators? There are stories floating out there of maintenance people thinking a fill valve on the boiler piping was a hot water tap.

As far as installing a condensing boiler, it could very easily make financial sense depending on what the existing heat source is. A good strainer is going to be necessary in a system with that much rust.

L. Collier

1925 hot-water system; rust in pipes

In our building of three apartments, built around 1925, we have recently had two vertical pipes of the heating system leak due to rust. We had several replaced, but I can still see a couple of vertical pipes to which the valves are attached with some rust . A master plumber said the horizontal pipes are fine, but verticals tend to rust.
How can we check the integrity of the system? Who should we contact? What technology exists, if any?
Two apartment owners want to replace the old furnace for a new more efficient one at a cost of $10,000. Is it worth investing this much in an old system which has had two pipes leak?

Thanks in advance for any advice.