Cast Iron Boilers, any good??

[caper150]

I think I'm close to finding a solution for my problems with my in-floor heat problems, I'm undersized for what I need and am now having natural gas hooked to the shop and want to use a boiler, now since I'm on a small budget I have been looking a a used boiler. I can find lots with in my budget but when I was talking to the plumber who was going to do the gas line install he told me to be careful of using a cast iron boiler for my operation because if the temp coming back to the boiler is too hot it will rot it out. Not sure what he meant but I think he means that I just need to regulate it right but he was talking about some type of loop the is needed to keep the temp right. Can anyone explain in layman terms what he means.

 

[koditten]

You should be able to find the installation manual for any current boiler (less than 10 yrs old). The manual will show you proper piping schematics.

You stated above that the boiler could rot out if the temp is too warm, what you meant to say was if the returning water was too cold. This is easy to do using a recirculation zone. If you search your boiler maunufacturer, and print out the installation manual you will see what I mean.

Using a cast iron boiler is an excellent way to heatg an in floor heat system. You just need to make sure it is plumbed up correctly. This is the fun part anyways.

This is what I did. Used boiler at a 1/10th the price of a new one. Couldn't be happier.

KO

 

[Jackfre]

The problem is that you need to have a return temp at the boiler sufficient to prevent thermal shock to the boiler. You can either crack or corrode a cast iron unit that way. You put a mixing valve on the return feeding the hot side with supply temp water. That will raise the overall return temp.

 

[sneezer41]

Save up your money and buy a new up to date unit. A used boiler is only coming out because it cost someone else too much to run. You will pay for it forever.

 

[caper150]

Thanks for the info guys this is the way I'm going for what I need.