Welcome! Here are the website rules, as well as some tips for using this forum.
Need to contact us? Visit https://heatinghelp.com/contact-us/.
Click here to Find a Contractor in your area.

Installing zone valve controller

jabbott Member Posts: 3
Ok what I have now is in the first picture. The house used to have two boilers. One was solid fuel fired, the other a really low efficiency natural gas. Last winter after I had some trouble, I replaced them both with a new high efficiency natural gas boiler. But since it was a really cold part of the winter, I just tied in the new boiler replacing the old one. We got through the winter, but it didn't really work too well.

The house currently only has two zones. The office zone, and the main house zone. What was happening was everything was fine with the house was calling for heat. I think because the pipes are big and that was the path of least resistance. But when the office was calling for heat, the heat flow was mostly going into the house and heating it up really warm. So, I realized I needed to add some zone valves.

Looking at the photo, power comes into the square D box then into the open box with all the wires. There is the small RIB24p relay hanging off the bottom. Then the two larger relays up top that seem to control the pumps. There are actually three pumps, one on the return of the main house, one on the return of the office, the third is on the boiler and controlled by the boiler itself.

I bought several zone valves, because I eventually want to setup a DHW tank as well. And in a couple of years I want to install underfloor heat in my kitchen. So, I bought some extra stuff. And, I purchased a Taco controller, pictured here as also.

The thermostat wires come in to the top of the existing relay boxes. What I am wondering is can I just tie the taco controller in by splitting the thermostat wire and running it both to where it is hooked up now and also to the Taco box? Which would be a super easy job. Or, do I have to do something different? But, if I decide to do a bigger job, can I get rid of all of this stuff somehow and just use the Taco controller in the place of (most?) all of this?


  • icesailor
    icesailor Member Posts: 7,265
    boiler control:

    The boiler installation manual has drawings on how to pipe that boiler. From what I see in the photo, you must have used the instructions from the old boiler. HTP is very specific on how to pipe that boiler. That was a good boiler but it is now discontinued because it got a bad name from so many systems being improperly piped.

    What you are trying to do is easy and common. I suggest that (if you can), find someone that knows what they are doing and pay them to help you.
  • ColoradoDave
    ColoradoDave Member Posts: 54
    Taco SR504

    First... icesailer is right, you'd probably be better off finding someone who knows the equipment to help you with this.

    However, if you insist on doing it yourself, I can't tell what Taco control you have there, but you really want a Taco SR504 (SR=Switching Relay).  It will turn on your pumps for you, handles up to 4 zones and when you're ready to do domestic hot water, you can prioritize the 4th zone.

    Since you're pumping on the returns towards the boiler loop, you can install Honeywell V8043 zone valves on the service.  Your thermostat triggers the zone valve with 24v, the zone valve end switch acts as the "thermostat" for your SR504 and triggers the pump.  If you still have a problem with heat migration, then install a spring check on the output of each pump.

    Icesailor was also right (that's the 3rd time I've agreed with him this evening), in that you need to check the manual and make sure you have a plumbing setup like one of the approved piping methods.  Primary / Secondary is my favorite....  Boiler loop comes out of the boiler, air elimation, pump and goes right back into the boiler - Primary Loop.  The secondary loops.. Office, Main Floor, DHW... come off the primary loop using closely spaced Tee's.... just close enough to fit a ball valve between them for purging the whole system at once those are your secondary loops.  There's other places for ball valves and boiler drains and such... but the diagrams will show you.
  • jabbott
    jabbott Member Posts: 3
    Installing zone valve controller

    I did write about it this spring here:


    It seemed like maybe I got good answers but for more money than I could really spend.

    ...And then motorcycle season started. ;-)

    So yes, you are right. I currently have the old plumbing system in place and it is plumbed the old way. I am hoping I can cure this for another year and build up to buy (something like?) what I put in that drawing.
  • icesailor
    icesailor Member Posts: 7,265

    The easiest way (in my mind) to solve some of the problems is to install a Hydraulic Separator and separate the boiler from the system. Then, it won't matter how you do it. You will be pumping INTO the boiler like you need to do, and you can pipe the system any which way you want. Using closely spaced tees with a ball valve between the tees, extends the spacing of how many pipe diameters to the edge of space, in MY opinion. With the Separator, it doesn't matter. The mixing is in the device, not in the closely spaced tees.

    Hydraulic Separators ROCK in problematic systems.
This discussion has been closed.