Boiler zone control

[toasty]

I want to separate one large zone into four separate zones. current setup is a b&g pump controlled by a Honeywell 845a relay. i would like to have four thermostats controlling 4 Honeywell zone valves (about 30 feet away from pump and boiler) not sure how to do this will a simple 4 zone controller do the trick like a taco zvc404? One more thing to note there are three other pumps in system each controlled individually by Honeywell 845a's.

Thank you to anyone who can help

 

[Dana]

First, what's the boiler (model make, BTU in/out) and how much of what type of radiation will you have on each zone?

Breaking it up into zones can potentially short-cycle the boiler into lousy efficiency and an early grave, even with modulating boilers. If you can share more information about the system it's possible to avoid most of the pitfalls. Many pre-existing boilers installed out there are already oversized for the whole-house radiation, and RIDICULOUSLY over sized for any individual micro-zones. It's possible to make it work reasonably efficiently, even with the oversizing factors, but this is much more than just an plumbing exercise.

It's also worth taking the time to run a fuel-use based heat load calculation before re-configuring the system. Both the boiler's oversize factor for the heat load, and the amount of radiation relative to the heat load may steer the possible solutions one way vs. another.