Black iron pipe in open vented system.

mR_Slug

Looking at designing a system based around a wood boiler that is required to be open vent. Copper is 3 times more expensive than black iron pipe. Now from what i've read cast iron and open vent is not the best thing. However I will be using a carbon steel boiler and cast iron radiators, so it will need inhibitor anyway. Then I've been studying old gravity systems. These are often open vent and black iron pipe and are 100+ years old.

What kind of inhibitor can be used in old open vent systems? Do they work?

hot_rod

should be able to find the open system treatments online

retiredguy

First you ask about black iron piping then mention cast iron. How about installing a totally sealed hot water system with absolutely no leaks or make up water. It can be gravity or pumped your choice. And what do you mean by "open vent" system? Most of the early steam or hot water heating systems were installed with wrought iron pipe when it was available and then black iron piping. Copper was only used because it was easier to work with, was faster to install, and almost anyone can learn to solder. If you want to have a good system installed why not call one of the contractors listed on this site. They do this work every day.

mR_Slug

retiredguy said:

First you ask about black iron piping then mention cast iron.

Yes they both rust.

retiredguy said:

How about installing a totally sealed hot water system with absolutely no leaks or make up water. It can be gravity or pumped your choice. And what do you mean by "open vent" system?

Open vent = unpressurized. The wood boiler is not rated for pressurised systems. Here in the UK they rarely are. Our code or regs are very different. It would be financially unviable to connect it to a pressurized system. Via heat exchanger in some of the methods in idronics 10 would be fine. However unpressurized or open vent thermal stores are the norm here.

retiredguy said:

Most of the early steam or hot water heating systems were installed with wrought iron pipe when it was available and then black iron piping. Copper was only used because it was easier to work with, was faster to install, and almost anyone can learn to solder.

Did not know about the wrought iron pipe. Done a lot of soldering both electronics and plumbing.

retiredguy said:

If you want to have a good system installed why not call one of the contractors listed on this site. They do this work every day.

I could do but I enjoy plumbing. I thought this was a place to discuss heating systems & their design?

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hot_rod

Thanks, the site you've provided answered some of my follow up questions. Love your lectures btw. Very interesting.

GroundUp

Any wood boiler inhibitor should be adequate in the proper concentration. Not sure what's available in the UK, but here, it's all pretty much the same stuff and can be purchased by the gallon.