primary secondary w/ outdoor reset

Dan_33

Installing three 84% eff. boilers and concerned when all zones call for heat and outdoor reset is set to low temperature supply that return water temp will be too low for boilers. Can you point me to a diagram that shows a primary secondary loop with the most effective way to control the return to an acceptable temperature for the boilers?

ALH_4

TV Valve

Thermic Valves are a good way to protect the boilers.

Rich L.

Tekmar

I've used this application on mutiple boiler setups just like you're talking about. The Tekmar 356 controller monitors outdoor temps to give you full reset control by way of an injection pump. You can also set it up to monitor boiler return water temps for boiler protection of non-condensing boilers. You could combine this with a Tekmar 264 boiler control then it would stage your boilers on and off as needed based on loop temps.

Check out:
http://www.tekmarcontrols.com/literature/acrobat/a356.pdf

http://www.tekmarcontrols.com/literature/acrobat/a264.pdf

Gerry May

What Kinda heating? baseboard? infloor? FanCoils?