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Boiler Control w/ Buffer Tank / Boiler Flow Rate

dtrani Member Posts: 25
I've added two small radiant zones to my system and I'm adding a buffer tank to limit cycling (cast-iron boiler). This will be a pri/sec system with the buffer tank serving as the isolator.

The buffer tank has an aquastat well which I was initially thinking I wouldn't use. I was just going to control the boiler using its existing internal high-limit aquastat, and keep the boiler primary loop circ running whenever there is any heat call. But I'm wondering if I should use an aquastat in the buffer tank to control the boiler, and shut down the boiler circ with the boiler?

The other question I have is, what flow rate should I be trying for for the boiler primary loop? This is an iron boiler so I'm thinking a fairly low rate, just enough the cover it's heat output of 50K BTU/hr. Thoughts?


  • Ironman
    Ironman Member Posts: 7,119
    How small are the zones in btus? With a cast iron boiler that small, you may not need the buffer tank. What type of emitters?
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.