Controlling Zone valves and Pumps

thermodynski

In short, I'm curious how you would control a low temp zone circulator pump when the rest of your zones have valves. long form below:

I'm revising the piping my house from an old gravity setup with CI rads to home run pex. In doing so, I'm going from 1 zone (zone circ on when boiler is on) 2 3 zones with the basement, main floor, an 2nd floor on their own zones. Keeping the Rads on main and 2nd floors and putting in radiant wall heating in the basement. DHW is a separate unit but I'd like to have the option of an indirect if it ever dies.

The plan is to use smart thermostats on each floor (So I need a C wire), balancing valves on uponor EP manifolds for balancing, and then maybe TRV's on the rads to get a little more room by room control if I need it.

2 Taco sentry zone valves on the 1st and 2nd floor and thew will be pumped by a secondary loop circulator (thought I've seen some setups where the boiler circ does this as well). This will be on ODR with 180 max temp. My boiler circ is grundfos 26-99.

the basement will be on a mixing valve and it's own circ. No zone valve needed here. This will parallel the ODR with a 130 max temp.

Boiler: Lochinvar knight 80 with their "SMART" features.

- One thought was a taco valve control unit (ZVC 404) and use the priority end switch to
run my low temp pump.

- Another way would be to just have a 2 zone valve controller and a 1 zone pump
controller that can talk to each other and use the DHW priority off one of those.

Just curious what strategy is most common/best. I'll verify sizing for everything after I have established my control strategy.

Thanks!

Rich_49

Wanting to know in simple terms w/o mentioning emitters how many Low temp zones and how many high temp zones ? I already understand that there is a DHW zone that will be priority

hot_rod

I'd like to see a piping schematic to confirm, but this Caleffi ZVR should work. The key is the 3 pump outputs and ability to configure their status. So the radiant would be zone 1. You would lose priority for DHW using relay 1 like this.

thermodynski

Rich, 2 high temp and 1 low temp.

HR, would a separate pump control re-enable me to use DHW priority. It's another controller to buy but that may be simpler for someone else to come service. The other question is is it worth it to buy 2 controllers for 2 zone valves and 1 pump. If I have to pump anyway, maybe just run 3 pumps + dhw.

hot_rod

A number ways to do this. Some, many control functions can be handled by the boiler control now. So you might just need a zone valve box to get you enough transformer to handle power hungry zone valve for example. Hard to design a control system when the piping info keeps changing and  info just trickling in.

thermodynski

Would I be better to just post up my system parameters and just let the folks at heatinghelp design it? Didn't want to bother anyone with that, kinda figured that was my job. 

How do I best help you help me?

Dave H_2

The ZVC-404 can control upto 4 zone valves but also the associated circulator. Whether they are Zone Sentry's or actuators on a manifold.

The SR panels can control your multiple circs zoning systems. You can use both in a system especially if using the -EXP panels, you can mix and match SR panels and ZVC's. This pic shows just SR panels, but they can be substituted for a ZVC.


If you have a sketch of your zone valves, circs, and the piping; we can probably find a way to control it.

Or if you want to peruse your options and the many, many different ways to wire and control, take a look at the attached book here.

Dave H.