Stopping Thermal Convection

Docfletcher

Hydronic heating,  boiler, fin tube system.  I want to open a zone valve manually so that when a different zone calls for heat I will get flow through the manually opened zone valve also. Because it's opened manually I get thermal convection and naturally I want to stop that. Would a ball cone check valve be a good choice? If so is the best placement near zone valve? This would be a horizontal mounting. Thanks  

hot_rod

What about wiring them together so they both power open together?

Docfletcher

Maybe. But there are two sets of 3 zone valves each power by it's own transformer. The zone I wish to manually open is on it's own transformer. The zone that will be on auto is on it's own transformer.

ratio

Perhaps a double pole double throw switch? I think that'd be a lot easier to add than a check valve.

Docfletcher

Guys, I'm not sure how to go about a using a DPDT switch. Would you care to explain how to do that? Thanks . My other thought was perhaps a larger transformer capable of handling 4 zone valves and wiring them as Hot Rod said. If I were to use a check valve of some sort which would be the correct type to use. Thanks

hot_rod

What type of zone valves? What size transformers, The transformer should say voltage and indicate VA volt amp. 40Va is typical and should run 4 of most types zone valves.

Send some pics.

If they are high draw type the end switch from the first can power the second so they don't all "hit" at once.

Docfletcher

TACO 555-050rp ,9A The zone I want to use manually or otherwise is all the way to the right, hard to see.

Docfletcher

One zone has no power head it of course is not in use at this time.

hot_rod

Ouch, sorry I asked

Looks like they put 2- 12V.6V transformers together at 2A= 25.6 Va each?

All those same colored wires are making my eyes water trying to decipher that cluster.

Docfletcher

Yes, Each transformer handles 3 zones. System works well, 25 years now. 1st time install. not pretty but she sure can cook.

Maybe the easiest thing is a check valve.

In the spring I'll try and get a new thermostatic valve in, just to ensure no condensation on the HE. I really worry about that.

SuperTech

I would install a zone valve control panel. Then you can really clean up that awful wiring. Wiring two zone valves to be controlled by one thermostat is a piece of cake at that point. Most zone control panels are designed to control four valves with a single transformer.

ratio

A DPDT switch would allow you to electrically disconnect the actuator from its current controls & connect it to constant power thus opening it. The switch could also be located anywhere you could conveniently get a wire to.

something like this:

Connect the actuator to the center terminals on both sides (marked 'bat'), connect the current wires to the top set of terminals, and constant power to the bottom set.

hot_rod

Do you want the "wild" zone to open with one specific, other zone? Or to flow when any other zone is calling?

If you want it tied to another zone, then wire like this.

If you want it always open, but not to get thermosiphon flow but flow with any zone, then remove the ZV and replace it with a hydronic check.

Caleffi NA51059 is a 3/4 sweat union, easy to install. It has the sme check you see in IFC circulators
.29 psi pop, conceal, quite design. Google that ngunnber to find a supplier with stock.

Docfletcher

I would really like 6 zone control panel, but that's just not in the cards at this time. The DPDT switch idea is interesting. I'll give that a little more thought. If I were to use a check valve it would need to to below the ball valve in the photo horizontally. All the way to the rear of the boiler. Up above it turns to 1/2" pex.

Hot Rod, why remove the ZV, could I just leave it in place and manually open so that I could shut the zone down when/if I wanted?

Thanks allot guys for taking time to help me with this.

hot_rod

Isn't zone valve that you operate manually just the same as the ball valve next to it?
Why not use the ball valve for on/ off control if the intent is to always have just manual control? What would the purpose of a disconnected ZV be, other than pressure drop in that loop?

So the check valve just installs where the ZV comes out.

A spring type check can go anywhere in any position in that zone. Installed below the ball valve may eliminate draining down the loop?

The check valve would be a simple non electric fix to prevent ghost flow if that is the primary goal.

But now anytime the circ is operating the "wild" loop gets flow. The ball valve could balance it, if need be.

Docfletcher

Here is another shot of the zone valves... Call them 1-6 from the left. Zone 6 when manually opened will flow well when any zone calls for heat. But, if circulator 1 (zones 1-3) is driving the flow zone 6 will flow in reverse. Go figure. Circulator 2 is for zones 4-6.
When zone 4 calls for heat zone 6 flows well also and it flows in the correct direction. When there is no call for heat from any zone the ghost flow sucks all the heat out of the boiler, right down to 100F.

I don't want to use the ball valve. to turn flow on and off.

I think for this winter I just want to stop ghost flow. Could I use this since I already have unions?

https://www.checkall.com/valvestyles/UIV/UIV.htm

hot_rod

Best I can tell that is an iron pipe size and looks like 100F temperature check.

You should only have flow in the zone that has a ZV open. If you have flow or backwards flow in a zone that is not calling, sounds like other problems, maybe a valve stuck open, or partially open

Docfletcher

Oh your right, it is for 100F.

I do have zone calling and zone 6 flows backwards because circulator 1 is driving flow. Circulator one is for the ZV's 1-3

When circulator 2 is on it drives ZV's 4-6. The only zone that can call for heat and have circulator 2 start is ZV 4. I think that because ZV 6 is Close to ZV 4 flow is normal.

When circulator 1 comes on due to call for heat... ZV 6 is far from it so for some reason like far from ZV 6 flow reverses.

No matter what circulator was going when the call for heat stops the manually open zone valve 6 allow water back up through the system return and sucks the hot water out of the boiler.

It is a valve open like you said but it is ZV 6 that is not electrically connected , just manually opened.