Taco wiring question

Tacotard

I cleaned up my wiring and installed a Taco 403-4 zone valve control. I have kind of a different system that was wired by a contractor that has left my area. There are 4 zones. 1 zone heats a baseboard zone on the lower level, one zone heats a baseboard zone on the upper level, one zone heats the lower level floor with radiant and 1 zone is for the domestic hot water. The previous wiring operation opened the radiant floor valve whenever one or the other or both of the two heating zones opened. I'm trying to figure out how to make the radiant zone open without adding a t-stat. This system worked great for years but it was set up with a priority relay for the domestic and on really cold days the house would get cold when the lovely bride would do laundry all day. It's a small house so running the hot water and heat at the same time isn't a big deal. what started the whole change out was a bad motor on the radiant zone valve, I just blocked it open for winter (warm floors are nice in Colorado in the winter!) but I want to get some control back. Zone valves are Honeywell V8043E1012. I wired the 2 baseboard zones and the hot water zone per Taco's diagram and they all work great. I just need to open (and close) the radiant zone whenever a heat zone calls for heat. Any help would be appreciated.

Rich_49

Why

didn't you purchase a ZVC 404-4 ? You could have spliced into the wires from both T Stats and run them to their own terminal to open that zone valve when either called for heat . I would change the Relay to the 404-4 . Easiest cheapest way and it will still be clean . If this worked for years it should still work . Hope this helped . 

Eric_32

I agree.....

You should have picked up a 4-zone control. You have 4-zones.... one of which needs a tsat wired or added (the radiant). If you can't run the wire, Honeywell makes wireless tstats now.



Look in your taco box.... there's only one transformer in there. I don't know about valves you have... but Taco's 571 are limited to 3- valves max to one transformer.



How many transformers did you have before adding the Mult-box?

Craig_CT

Taco SR504 with Honeywell V8043E1020 zone valves. Troubleshooting and Best Pratice

Hi, I have a single story ranch home with an unfinished basement below that had 2 heating zones (the 1st zone for the main living area and bedrooms, the 2nd zone for a small porch that was converted to year round space).  The floor plan is very closed so having a T-stat in the main living area does a poor job of regulating the temperature on the bedroom side of the house.  Over the summer I split the plumbing so the bedrooms would become a 3rd zone.  I installed two Honeywell V8043e1020 zone valves so I could continue using the same circulator pump. However, I never got around to doing the wiring (had other warm weather projects to attend to) so I've had the valves manually open this heating season so basically the house is still two zones.  Now that I'm back to completing the wiring I've come across an issue and would appreciate some help.  I have a Taco SR504 controlling the two zones and was going to use the 24 V lug to power the zone control valves.  When I put my multimeter on the 24 V lug on that board (I've learned the hard way to test everything before making a connection), it was outputting .3 V and the common lug was outputting 22.3 V.  Digging in a little further I found whoever installed the SR504 wired the 120 V in backwards; the hot was on the neutral lug and the neutral on the hot lug.  I corrected this and now the 24 V lug is outputting .3 V and the common lug is outputting 2.5 V.  Does anyone know if the backwards wiring could have damaged the 24V transformer that is built into the SR504?  If so, it looks like it may be a serviceable part, does anyone know if that is the case?  Could there be further damage to the board?

Regarding my zone valves, once I can get 24 V, my plan for each valve is to put 24V to one yellow wire (yellow are motor), connect one yellow wire to a wire from the T-stat and put the other T-stat wire to a neutral.  The two red wires from the zone vale would go to the T T lugs on the SR504 where the T-stat wires had been connected.  Does this sound correct?



Thanks in advance for any help.

Zman

SR 504

I don't think the transformer or board were damaged. This is not the first time one was wired backwards.

23.3 is a little low. What does the 120 volt circuit on the line side measure? If it is also a bit low, you don't have a malfunction.

You need to see if the on board transformer has enough va's to run your zone valves.

It sounds like this will work, you may need to set another transformer for the valves.

Carl

Dave H_2

ZVC controller would be best

A Zone Valve Controller (ZVC) would be best to use here. The SR panel is meant for multiple circulators.

The transformer on-board is designed to power the circuit board and any thermostats. It may not be large enough to handle the extra power for the zone valves.

Your thermostats and zone valves would wire to the ZVC controller and then from there, wire the end switch to the existing SR panel to turn on the associated circ.



Dave H.

Craig_CT

SR504 Continued

Line side coming in is 119.6 V.  Any thoughts as to why I only get close to 24V when wired backwards?

Craig_CT

ZVC controller would be best

Hi Dave, Thanks for your input.  As mentioned, I am wiring in two, 4 wire 24V Honeywell valves and will be adding a 3rd in the not too distant future when I finish a section of the basement.  With that said, is there a particular brand/model that you would recommend?

Zman

Mis-read

Sorry I mis-read your post. At .3 the controller must not be working at all. Are you checking from hot to common or hot to ground?

Carl

Dave H_2

Taco ZVC-403

Is a three zone/ valve contoller



http://www.taco-hvac.com/products.html?current_category=408

Craig_CT

Voltage

Hi Carl,



It's .3V when I use the common and .2V when I use the 120V line in neutral.  It seems something is wrong with the transformer that is mounted to the board and/or the board itself.  I'm going to go with Dave H's suggestion of installing a ZVC and just let a sleeping dog lie on my SR as I don't have a need for the 24V from the SR if I install a ZVC.  Thanks for your help.



Craig

Craig_CT

ZVC-403

Thanks Dave, I'm going to pick one up over the weekend.



Craig

hot_rod

oops wrong location

Craig_CT

Removed post

Craig_CT

ZVC403 Voltage

Hi Dave,

I installed a ZVC 403-4 as you suggested and it's working as desired but I have one issue/question.  I have the X X pump end switch terminals connected to the T T terminals on zone 1 of  the SR504 to fire the circulator pump.  The odd thing is, when I ground out one probe of my multimeter and test the lugs I get 29V, I was expecting 24V.  I know fluctuations are normal, say in the 22-26 V range but I'm surprised to see this as 29V.   My line voltage in is 121V so that is almost spot on.  Does that sound normal to you?  Is there anything you know of that I should check if it's not normal?

Thanks

Dave H_2

24 volt power

Craig,



24 volt power from a transformer can be higher than expected. You are OK.



Glad everything is working well