Whose Double Wall Indirects are you using?

The Steam Whisperer

We use these mainly in 6 flats and they need to be double wall (Illinois plumbing code). I was using HTP Superstore stainless units , but HTP has stopped producing these double wall models. The 80 gallon units seem to work well with the steam boiler providing hot water.

Alan (California Radiant) Forbes

Mercifully, the UPC dropped their double-wall requirement about 10 years ago. We were using Superstore’s and a few Amtrol’s. 

jumper

Alan (California Radiant) Forbes said:

Mercifully, the UPC dropped their double-wall requirement about 10 years ago. We were using Superstore’s and a few Amtrol’s. 

I didn't know that. Before double wall was coded in in the seventies I never heard of anybody harmed by water contaminated with steam or refrigerant.

Alan (California Radiant) Forbes

I didn't know that. Before double wall was coded in in the seventies I never heard of anybody harmed by water contaminated with steam or refrigerant.

I think they were more concerned about chemicals added to the boiler water getting into the domestic water system.

Alan (California Radiant) Forbes

I just noticed that Laars has double-wall indirects.

https://www.laars.com/images/uploads/products/11027E-NH.pdf

They also have single-wall, stainless steel models, but I don't remember them being mentioned here on HeatingHelp. Has anyone ever installed one?

Their MiniTherm boilers have been redesigned and are now JX models; the 125K and larger come with low-loss headers. Pretty much the same design as their JVS models. I've come around to liking these boilers; many in my area are still going strong after 20+ years and they are comparatively easy to service.