Taco ZVC with Honeywell TH-5000

Marty

Have you checked the phasing on the transformers ? someone posted an excellent way on how to do that recentley. edit..... you probably need another transformer and relay if you are using the diagram on p 54 tstat look at the diagram on p 53 that is what I was looking at at first.

Might want to look into another transformer and a relay withthe points jumping the thermstat connections at the zone control.

John McArthur_2

Wiring issue

I have been attempting to connect a 3-wire Honeywell TH-5000 (Focus Pro) to a Taco ZVC-406 zone control. Honeywell tech support assures me that the stat is non-power robbing and doesn't require a resistor. They only require a common to return to the transformer. The problem is that everywhere I have attempted to connect to common on the ZVC board results in a HUGE current draw, enough to make the lights on the control dim. I called Taco also but still no luck. I think it is a circuit board issue. I also tried a number of different zones to make sure it wasn't just a bad wire or zone valve.

Has anyone found a solution yet? The wiring diagram that Taco provieds in their wiring manual doesn't work, nor does connecting directly to the transformer connection to the circuit board. I also have the same problem with the Tekmar 510 stat and the ZVC.

Diagram attached

John McArthur_2

Wiring issue

I have been attempting to connect a 3-wire Honeywell TH-5000 (Focus Pro) to a Taco ZVC-406 zone control. Honeywell tech support assures me that the stat is non-power robbing and doesn't require a resistor. They only require a common to return to the transformer. The problem is that everywhere I have attempted to connect to common on the ZVC board results in a HUGE current draw, enough to make the lights on the control dim. I called Taco also but still no luck. I think it is a circuit board issue. I also tried a number of different zones to make sure it wasn't just a bad wire or zone valve.

Has anyone found a solution yet? The wiring diagram that Taco provieds in their wiring manual doesn't work, nor does connecting directly to the transformer connection to the circuit board. I also have the same problem with the Tekmar 510 stat and the ZVC.

Diagram link below (page 54)

http://www.taco-hvac.com/uploads/FileLibrary/100-9.0.pdf

Thanks in advance

John McArthur_2

I think I posted the page number incorrectly. Good catch. The relay and transformer has already come to mind but a good point non-the-less. I hadn't thought of phasing, I'll look at that next. I am leaning toward the power distribution on the circuit board as the culprit. I have installed many similar thermostats with out the zone control without any issues. It seems logical that taking to common from the stat to the common from the transformer work fine, but it does not. I have "stolen" power from the control's transformers many times to use for my enable circuits without any issues as well.

Thanks for the reply, this is a frustrating issue. I'm the type who gets really stubborn about finding the root of the problem.

carol_3

What happens when you install the stat with the batteries in it, without the C terminal connected? That stat can function just fine as a 2-wire stat (R and W terminals)so long as it has batteries.

John McArthur_2

Thanks for the reply Carol. The stat works fine w/o the common connected to the ZVC. The stats also work fine when field wired with a transformer and the common connected to the trans. The only problem is when using the ZVC.

I really like the new thermostats, they are inexpensive, simple for the HO to operate, and very flexible.

If I measure from the common to the #1 ZV terminal on the control (recommended by TACO), I have ~26vac. Although, when I connect the common there is such a large draw that the LED's on the control go out. I briefly connected the common with a amp meter around the wire and saw ~ 23a! I tried several different zones to ensure there wasn't a problem with the wiring or ZV motor.

I generally prefer to field wire the zone valves, but I do have a few clients who like the ZVC's and I have one project that I am using them on. I would like to resolve the issue b/c of my own curiosity.

Thanks all for the responses, it is greatly appreciated.

John McArthur_2

Carol,

As an aside, I attended one of your classes several years ago and just wanted to say your common sense approach and ability to make clear confusing subject matter was impressive.

It has been many years since the training and I still remember some of your examples and use the same technique when training apprentices.

john gapinski

phelon control to standard r8184g

How do I wire an R8184G control in the place of a phelon control? Could you please explain what color wires are connected to the 8184g?

Thank You!!!!!

carol_3

Thank you!

carol_3

The best I can tell you is to go to the Honeywell website for a disgram of the R8184G if you don't already have that. Go to http://customer.honeywell.com. Scroll down to the very bottom right corner and type R8184G into the blank box. On the next page look for installation instructions. Inside that, look for the wiring diagrams.

Jeremy_14

I had the same problem

   Doing a google search I found this thread which discussed the problem I was having but didn't have an answer.  This is what worked for me. 

       I'm installing a system with two Taco ZVC 406 relays with heat only R W C thermostats, one pump for each relay with actuators contolling the zones.  The thermostats can be battery powered, but with a lot of zones, I didn't want the customer to have to change a lot of batteries every year. 

       The ZVC 406 comes with two 40va transformers.  Disconnect one of the transformers from the relay.  This transformer will be used to only power the thermostats.  One side of the transformer (for me it was the red wire, use your meter to make sure, transformers change, colors change) doubles up with W on the thermostat, or where the white wire connects to TT on the relay.  The C on the thermostat goes to the other (yellow wire) side of the transformer. 

       If your system uses zone valves that need both of the transformers to operate, then you'll need a third transformer to do the above, or to power the relay board.