Here's what I have:
Radiant floor heat boiler setup with circulator pump for primary and 3 circulator pumps for secondary loops.
- 1st secondary loop has a manifold with 2 actuators
- 2nd secondary loop has a manifold with 3 actuators
- 3rd secondary loop has a manifold with 4 actuators

I've been looking at taco ZVCs but have not been able to find any suggestions on how to wire a setup like that where I'd have circulator pumps AND actuators for the secondary loops.

Would I be able to get this done with using multiple ZVCs or would I additionally need a relay for the primary pump?

What I THINK would work might be:
- 3 individual ZVCs to control each secondary pump and the actuators
- relais to have each ZVC also control the primary pump

Would that work? Any better ideas?

Thanks,
Tim

Alternative thinking.
Assuming 1/2" loops of about 300' or less.
One Grundfos alpha pump, aim at 3 manifolds all with actuators, set Alpha to Auto plug Alpha into the wall. Done
Thermostats to TACO ZVC box, ZVC box turns on boiler as needed.
Alpha comes on automatically and will vary flow based on circuit open,
Dan

Dan,
You're saying I can just keep the Grundfos Alpha plugged-in (and on) even when all actuators are closed?
Are they completely shutting of when they detect that a loop is closed?
Thanks,
Tim

yes,

To easy, pump will come on when actuator opens,
when more open pump will increase water velocity to hold pressure /flow
as actuators close pump velocity will slow
actuators shut/pump off
to easy
magic !!
Dan

Dan’s proposal is sound. The thermostats will call for heat. The Taco zone valve controller will then begin to open the zone valves. When the zone valves are open, the Taco zone valve controller will then turn on the boiler and turn on the pump via a relay. The Grundfos Alpha will modulate flow rate based on sensed hydraulic friction (head at pump). To be extra safe, you should place a pressure by-pass valve next to the pump to absolutely ensure that it will never get dead-headed even if all the zone valves are closed and the pump is running.

Great, thanks!

I might give it a try without using the by-pass valve and see how the pumps react when zone valves are closed.

Grundfos Alpha pumps are designed to stop when there is no option for flow.
Can't deadhead them!
No by pass necessary and would be wrong if installed.
Same is true with Grundfos Magna pumps.
We build these pumps into our pre assembled pump distribution systems regularly.
Wide range of flow, can meet multiple system situations optimized and is ECM motor driven, high efficiency.
Dan

Thanks, Dan!

Grundfos recommends the use of a by-pass valve with the Grundfos Alpha pump “to ensure that the heat from the boiler can be distributed when all valves in the heating circuits are closed.” See page 13 of Grundfos Alpha Installation & Operating Manual:

Grundfos Alpha2 Installation & Operating Manual

So while the pump should handle dead-heading while in smart mode, it isn’t clear that it will handle this at other pump settings. More importantly, the minimum boiler flow rate should be considered and may need to be protected.

OK,
Lets stay with the Alpha pump that is for the USA market. The ALPHA 2 is not available in USA,.
Here is the Alpha USA manual
http://media.blueridgecompany.com/documents/Grundfos_Alpha%20Install.pdf
No By pas mentioned, further in my specific conversations with my friend and Western regional rep manager with Grundfos regarding this very point dead heading is not the issue.
If boiler issues are involved as you mention perhaps better (proper) primary secondary loop is preferred.
We use these in dead head configurations regularly. That said our pump panels for the most part are all designed primary secondary.
Dan

We have used the Alpha2 in both the UK and in the USA for off-grid 50 Hz applications (cheaper Chinese PMGs). While certainly not common in the USA, it is available. Having disassembled both the European and USA versions, there isn’t much difference in the designs relative to how they behave when faced with zero flow rate. The Alpha2 does come with a check valve installation option, but this wouldn't affect dead-heading. So I suspect the absence of the by-pass guidance in the USA manual is likely just an oversight.

In any event, my concern and by-pass precautionary extra safety measure recommendation, is more with protecting any minimum required boiler flow rate. Agreed, a primary/secondary having adequate pump hydraulic separation would certainly address this concern. Dan, I assume the OP doesn’t have your panel or he wouldn’t need to ask questions like this on a public forum...you would have addressed all questions/needs. Not having the OPs HR design schematic left this a potential open issue in my mind and worth mentioning.

We designed an apartment house system, 6 floors, each riser stack served 12 units, zone valve on each unit. S imple design supply up dead head to zone valve, valve opens pump. No wiring to pump other than 120 v energy to run, In this case we were using a Grundfos Magna due to flow in max operation, same control logic though.
The engineer had a look at the design and slipped a bypass at the top of the supply lift . Thinking it was the proper way to make things work that bypass was then installed by the site contractors. Upper floors did not get heat. Only after the by pass was removed and the pump was able to properly dead head (original design from BlueRidge Company) did the system work.
Dead heading an alpha or Magna is fine. They are designed for that. As I have said before I have had this conversation with the Grundfos western regional rep (oversees local reps in western united states).
I do not think the manual has an oversight, to the contrary, it is the beauty and another design tool of the Grundfos Alpha.
So again boiler primary secondary may be required, that is a boiler issue, as to the pump rock it with a dead head!
Dan

Pumps should always be selected/sized such that they will operate at their BEP (Best Efficiency Point) when all the zone valves are open for maximum pump efficiency and life. Pumps should never intentionally be placed into service such that they will exceed 80-90% of their maximum head, much less be exposed to frequent dead-heading. While variable speed pumps utilizing smart controllers and having motor protection provide increased design/safety margin, competent design practices should still always be followed.

I suspect the engineer in your example was indeed correct and you likely undersized the pump for this HR system. Over and under sizing pumps is a very common problem in the largely untrained/unlicensed HR industry. A pump shouldn’t need to be dead-headed in order "to get a system to work". There is never a need to intentionally block a running pump to get a system to work.

Oh boy,,
Here we go again, pretty much why I stopped posting on this forum was the trouble communicating with someone so "smart"
But , I hold to my simpleton truths.
Alphas are designed to dead head as needed.
Magna pumps among other features are designed to dead head.
ECM motors are designed to crawl or ramp full speed. Energy measured in watts decreases when at a crawl.
I suggest that if you disagree with their design and marketing you take it up with Grundfos, to prove you point in their laboratory.
I have no opinion just design and sell as what I am told by manufactures what the products will do.
As to the apartment house I mentioned, you are a bit presumptive to assume you understand the issues at hand based on the brief description.
My design and pump flow was correct, the engineer that drew the working set of plans and build to did not understand the reason not to have a bypass and was concerned for dead heading (not shown in the preliminary set, just the build to set). That person changed the design to the traditional by pass method . The change was on the submitted Build set of drawings some 120 pages a tiny detail on page 76 that was not in the original preliminary set. This change result was both the 5 and 6 floors not to receive heat due to the by pass. In this application described the bypass was buried on the 6th floor.
The fix was to remove cabinets, open the walls, remove the bypass all 4 days before occupancy.
Once done the system worked flawless and continues to do so.
I might add the system is 12,000 square feet, solar assisted heat and domestic hot water in Seattle, Washington.
Dan

Oh well, we will just have to agree to disagree. Diversity of opinions is a good thing, so please do not contribute on account of me. People can fact check forum opinions and come to their own conclusions.

Deleted duplicate post.

Not really about agreeing or disagreeing.
It is about Manufactures recommended applications and application options.
We (the consumer public) have to assume that the Manufacture in this case Grundfos the multi national manufacturing and pump design company with some 17,500 odd employees scattered about has in fact designed a pump that can be dead headed and works with ECM technology so it can run at a huge swing of rpm based on a pressure differential setting.
Before you know it TACO will have something like that....
My bad, have a look at TACO Varidian
This is one of the directions pump technology is heading, the beauty is that we have a much greater control of flow, design options and 1/5 or less electrical consumption.
More for less,
Go figure....
Dan

And when we look at Taco's plumbing diagrams for an ECM circulator, we find it deadheaded into zone valves:

http://www.taco-hvac.com/uploads/FileLibrary/102-517.pdf

jonr, that is not possible.....she can't be wrong.....

Dan, thanks for your great info and teaching for others to learn.

Thanks the good words,
Always appreciated,
Dan