Three way valves and how to control them

nancyl

First of all thank you for all the amazing help on some of my past questions. I have another

The picture below (left side of green line) is of a simplistic three zone, glycol hydronic heating system. It does not display all the actual components (air separators, pressure valves, etc.) to keep the discussion focused.

This is proposed to be added onto an existing radiant heating system so the boiler, circulation pump and system pump are in place and functioning as expected.

This system has the following requirements:

• None of the zones will ever be on at the same time as another.
  
• Each zone will be turned on and off via a manual toggle switch
  

The existing radiant system (right side of green line) includes a DHW loop to an indirect water heater and several heating zones controlled by zone valves and thermostats. It is managed using two Taco 4-Zone Valve Controls w/ Priority, Expandable (ZVC404-EXP-4). Heat is provided by a Triangle tube condensing boiler

My question is what is going to be the best way to wire this glycol system in? When any of the three zones is turned on, the following should happen:

1. The boiler should come on
   
2. The system circulation pump should come on
   
3. The Glycol circulation pump should come on
   
4. ZV3 should open
   
5. The 3-way zone valves should open according to the zone turned on.
   

If the design should be changed to remove the three way valves that's an option, but I have the same question about how to energize all the ZV's and circulators on both sides of the green line that will serve the glycol system.




Is there a specific control board that will meet my needs?

Jamie Hall

There may or may not be an off the shelf control board which will accomplish all that -- but it wouldn't be at all difficult (particularly if you used regular zone valves) to accomplish the same thing by clever wiring of the zone valve end switches and a few relays. hmmm... could even do it with only one or two relays, and the control switches as SPDT, unless there was a requirement that you had to turn all zones off before activating any one of them...

hot_rod

Afe the 3 way valves for temperature mixing? Or just diverting?
Could all those zones 1,2&3 have the same supply temperature?

EdTheHeaterMan

I assume that these temperatures are from some other diagram. Because they don't make sense.
Aside from that, what will control the heated water operation for heat emitters in the glycol system? Only the toggle switch or is there a temperature sensor? Glycol indicates the tubing may be subject to temperature below freezing, so maybe it is a snow melt system. As one zone is cleared of snow and ice, the operator will manually switch to the next zone and rotate as needed until the weather changes?

When ZV#3 is open to allow boiler heat to the heat exchanger, will that need to shut off the "Other zones for radiant floor heat and DHW" to the right of the green line. Or, does that also need the be active during the glycol system operation? This makes a difference in my idea for your control.

MikeAmann

@nancyl
These guys are very smart. As you can see, they have already jumped 3 steps ahead of the data that you purposely left out. Just tell the whole story - it will be less painful.

nancyl

hot_rod said:

Afe the 3 way valves for temperature mixing? Or just diverting?
Could all those zones 1,2&3 have the same supply temperature?

Yes, only diverting. There is a mixing valve down stream if zone 3 needs a different temp than 1 and 2 otherwise it is intended to be the same temp for all three zones.

nancyl

EdTheHeaterMan said:

I assume that these temperatures are from some other diagram. Because they don't make sense.

Yes, just borrowed the images from a different source.

EdTheHeaterMan said:

Aside from that, what will control the heated water operation for heat emitters in the glycol system? Only the toggle switch or is there a temperature sensor? Glycol indicates the tubing may be subject to temperature below freezing, so maybe it is a snow melt system. As one zone is cleared of snow and ice, the operator will manually switch to the next zone and rotate as needed until the weather changes?

Yes, completely manual via a toggle switch, no timer or sensors.

EdTheHeaterMan said:

When ZV#3 is open to allow boiler heat to the heat exchanger, will that need to shut off the "Other zones for radiant floor heat and DHW" to the right of the green line. Or, does that also need the be active during the glycol system operation? This makes a difference in my idea for your control.

ZV3# does not care about the state of the other components to the right of the green line. It just operates based on one of the three zones to the left being turned on or off. Of course the boiler must also turn on when one of the three left side zones is turned on.

hot_rod

I don't see why the 3 way valves? Have you priced them? About 120 bucks more then 2 way valves.
Counterflow through a plate HX

EdTheHeaterMan

Do you already own the 3 way valves?
Are they already installed?
And we do not need to turn off the main "Other Zones" to operate the new manual sections to the left of the green?

EdTheHeaterMan

@nancyl This might work when the 3 way valves are de-energized the flow turns to the bottom 100%. When the valves are energized the flow is strait thru 100%
Switch #3 will send the heated water to zone 3
Switch #2 & #3 will send the water to zone 2
Switch all three switches will send water to Zone 1
Any of the valves turned on will operate the boiler from the top X X end switch and the glycol system circulator from the bottom C to NO switch contacts.

If the valves are opposite then there is a different result:
Switch #3 will send the heated water to zone 1
Switch #2 & #3 will send the water to zone 3
Switch #1 & #3 and #2 is OFF will send water to Zone 2
Any combination of ZV #3 and any other switch position will offer you only operation of one zone at a time.

nancyl

hot_rod said:

I don't see why the 3 way valves? Have you priced them? About 120 bucks more then 2 way valves.
Counterflow through a plate HX

Was contemplating something like this which is about the same cost or a bit less than a Taco ZV

https://www.electricsolenoidvalves.com/1-inch-brass-3-way-electric-ball-valve-3-wire/

nancyl

EdTheHeaterMan said:

Do you already own the 3 way valves?
Are they already installed?
And we do not need to turn off the main "Other Zones" to operate the new manual sections to the left of the green?

Do not own any of the ZV yet. Contemplating something like this for the 3-way.

https://www.electricsolenoidvalves.com/1-inch-brass-3-way-electric-ball-valve-3-wire/

No, nothing on the right of the green line needs to be turned off.

nancyl

EdTheHeaterMan said:

@nancyl This might work when the 3 way valves are de-energized the flow turns to the bottom 100%. When the valves are energized the flow is strait thru 100%
Switch #3 will send the heated water to zone 3
Switch #2 & #3 will send the water to zone 2
Switch all three switches will send water to Zone 1
Any of the valves turned on will operate the boiler from the top X X end switch and the glycol system circulator from the bottom C to NO switch contacts.

If the valves are opposite then there is a different result:
Switch #3 will send the heated water to zone 1
Switch #2 & #3 will send the water to zone 3
Switch #1 & #3 and #2 is OFF will send water to Zone 2
Any combination of ZV #3 and any other switch position will offer you only operation of one zone at a time.

This is getting closer to what I have in mind. I'll study this. Thank you!

hot_rod

Looks like a 3 way motorized ball valve, not a solonoid. If so you probably need to power it open and power it closed, a 3 wire valve. No spring return and no end switch?

nancyl

hot_rod said:

Looks like a 3 way motorized ball valve, not a solonoid. If so you probably need to power it open and power it closed, a 3 wire valve. No spring return and no end switch?

They make a separate actuator that will auto return If this is the way I proceed.
https://www.electricsolenoidvalves.com/replacement-electric-ball-valve-actuator-2-wire-auto-return/

EdTheHeaterMan

With a 2 wire valve actuator the valve actuator wiring changes slightly. See if you can find it.
This like those picture games we give to out kids to find the difference LOL

hot_rod

Just so I’m not missing something, why 3 way valves instead of 2 way?
So zone 1&2 can’t flow when zone 3 is? Not all 3 zones can operate at once, as I see it.

Derheatmeister

hot_rod said:

Just so I’m not missing something, why 3 way valves instead of 2 way?
So zone 1&2 can’t flow when zone 3 is? Not all 3 zones can operate at once, as I see it.

@ hot_rod
From nancyl original Post:
system has the following requirements:
None of the zones will ever be on at the same time as another.
Each zone will be turned on and off via a manual toggle switch



@ everyone involved with this design:
Not sure why everything needs to be so complicated using 3 ways vs regular 2 ways since the full story is not revealed one Can only speculate..

hot_rod

More question than answers. How you get 140 DHW with 102 supply to the HX?

What happens if toggle 1 is on calling for heat, but so is toggle 2?

If a manual system is the goal, just us some ball valves, skip the zone valves, relay and toggles and save $$

EdTheHeaterMan

hot_rod said:

More question than answers. How you get 140 DHW with 102 supply to the HX?

What happens if toggle 1 is on calling for heat, but so is toggle 2?

If a manual system is the goal, just us some ball valves, skip the zone valves, relay and toggles and save $$

I asked the same thing and for this response

The ZVC Relay has stuff already existing that will operate the boiler and the Glycol zone pump. The 3 way valves mean that only one zone at a time can be heated. Based on the information given, I thought this was the easiest solution. The "Why?" query may never be revealed. perhaps we can call it

The Case of the Unknown Zone

And get the old crew from the last Case of the Noob and the Cold Bedroom on it!

nancyl

Thank you all for your comments.  Appreciate the advice and suggestions.

clammy

I think u may need a professional hydronic designer to lay your piping out . As much as a lot of people believe it’s easy it’s not until you have to pay someone to redo and straighten out a mess the is not designed or function properly without constant fiddling which means it’s not really a automatic heat system . I would stick to a standard 2 way valve like taco usually always available and quite easy to wire just about any one is familiar w them why complicate things .I personally don’t understand the reasoning behind all the manual toggles switches they make controls for this and who wants a system that only one person knows how to operate makes zero sense in 2023. And when issues do arise and a professional is called in I hope your present to explain how’s it suppose to work while he scratches his head between flipping toggle switches and waiting for some thing to happen . Just remember he will be billing you while he is scratching away trying to figure out your mess, just cause he’s there doesn’t mean he wants any liability or to be married to it, it’s not his it’s yours .
I don’t want to sound harsh but I ve seen others attempt things that out of there realm and pay the consequences heavily and all they did was say it looked so simple yeah until the result you except are not what you get .if you design and some one is piping when it doesn’t work its not on them its on you there just following your design ,there getting paid to put it together not redesign some thing that was not design properly . Again just don’t want to sound harsh but telling it like it is .
Peace and good luck clammy