Taco ZVC406 and Intellicon HW+

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Seeking some advise for the near-term and future.
(We live in upper New England and only use window air conditioners as needed during the summer.)
Our main energy use is oil which heats the house with the help of a wood pellet stove.

I have reviewed a lot of online blogs and videos, but because I have not studied how my system is currently running in any depth, I'm not sure about these items puzzling me so far.

My current heating system has the following:
-A zone for each floor of the house including the basement, = 2 baseboard heating zones plus a Modine for the basement.
-An indirect DHW storage tank wired as a fouth zone, it does not have a seperate circulator only a zone valve.
-All 4 of the zone end switches are wired in parallel, and feed the Honeywell L8151A Aquastat on the T-T/3 terminals
-Each zone has its own setback thermostat (except the basement which uses a regular thermostat) connected to its zone valve, the DHW being run by the L4080B Aquastat on the storage tank for the 4th zone valve.
-The boiler is an Ultimate PFO-4 with a Beckett AFG burner and an R7184B burner control.

My first system upgrade will be to install a Taco ZVC406 to cleanup the zone valve wiring and provide me with a better system status.

My first question is this:
Should I move control of the system circulator to the Taco ZVC406, or leave it on the L8151A Aquastat C1 C2 terminals?


Next, I want to install an Intellicon HW+ on the L8151A Aquastat to try to optimize burner cycles and save some on fuel oil.

My second question is how to set the Intellicon?
I currently have the Aquastat set ~182 for the Hi Limit, the Lo Limit is turned all the way down (~110), and the Diff is set to ~15.
What would be your recommendation for the HW+ settings?
Should I change any Aquastat settings or leave them as is after installing the HW+?


In the future I might upgrade the Aquastat to an L7224U, but that might be down the road a bit.


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Peace valley missouri
Guess your not running out of dhw the way the controls are wired. The taco control will give you dhw priority which you don't have. The only other thing is lights showing zone valves are powered. Lights can be added to the zone valves a boiler outdoor reset might give you a small energy savings. Normally i would want a high low limit setting above 140° with a differential above 130° for the burner not to condensate. Cast boilers like to be warm as to not be shocked by cooler water that can crack a section. Apparently your not.running into that problem. How does the refractory look?
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