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Taco SR504 Indirect DHW wiring

dvizz
dvizz Member Posts: 39
edited January 2017 in Gas Heating
I want to replace 3-24v relays that power 3 Taco circ. with the SR504. My question is how do I energize a relay mounted on the Weil Mclain board. The WM 24v circut is used to power the relay through the aquastat which powers a 3 way valve to send hot water flow from the boiler to the indirect, closing the flow to the baseboards. I want the SR504 to prioritize the Indirect and the way the system is wired now the baseboaed pumps will run even when flow is diverted to the Indirect. I see the aquastat wiring going to the thermostst terminal #4 and the boiler TT wiring going to the end switch to prioritize the indirect operation.

Comments

  • Paul48
    Paul48 Member Posts: 4,492
    The sr 504 is used to control and or prioritize circulator function. We'll either need a lot more information, or you'll need someone on-site to sort out what was done initially.
  • Zman
    Zman Member Posts: 6,452
    You will need to post some pics and drawings on this one. The manual for your boiler control would be helpful as well.
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • dvizz
    dvizz Member Posts: 39
    I have 4 relays mounted remotely from the boiler that when each thermostat calls will pull a relay in, starts a Taco Circulator and opens a Honeywell zone valve. I am removing the zone valves and installing flow control valves in their place. The SR506 will control the circ. pump only.
    My issue is how do I get the SR506 to energize a relay that is mounted on the WM control board and closes when the indirect aquastat calls.
    The relay sends power to the 3 way diverter valve. This set up is wired from the WM transformer. The system was wired by some hack and what is troubling is the circulators run even when the indirect is getting fed from the boiler as the diverter shuts flow to the base board lines. The WM has a circ. that will run whenever there is call from the room stats or the aquastat.
  • Paul48
    Paul48 Member Posts: 4,492
    Where is the 3-way diverter valve?
  • Zman
    Zman Member Posts: 6,452
    What model is the boiler and diversion valve?
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • Paul48
    Paul48 Member Posts: 4,492
    You know what I was thinking, I take it?
  • dvizz
    dvizz Member Posts: 39
    Weil Mclain Model -GV-5
    Diverter Valve - Honeywell V8044A10444
  • Paul48
    Paul48 Member Posts: 4,492
    We are hesitant offering advice because everything we see is wrong and cobbled up. Also, everything you're describing, that we don't see, is wrong and cobbled up. We can't tell what's circulating the water to the indirect, or why it would require a 3-way valve. You say the boiler has a circulator...Is the system piped primary/ secondary? We want to help, but we need pictures showing the whole system, or diagrams of it.
  • Zman
    Zman Member Posts: 6,452
    I agree with Paul that we need more info.
    I am guessing that this can be done if you add one more relay to deal with the 3 way. Why it is there and how your system is piped is still a mystery.
    Just trying to make sure you get it right.
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • dvizz
    dvizz Member Posts: 39
    Guys the system has 4 circ. and 4 zone valves. Each circ. and zone valve are controlled by individual stats. The boiler also has a circ. inside the jacket. Whenever a room calls for heat the boiler starts up, the affected zone valve opens and the circ. for that zone comes on. I am removing the zonw valves and installing flow control valves so I can use the SR506, which will control the circulators through the individual room stats.
    The boiler also feeds an indirect, so when the aquastat calls for hot water the boiler circ. pump comes on with the boiler and the 3 way opens the port to the indirect and closes the port to the base boards. The relay shown on the photo of the control board was installed to open and close the 3 way when the aquastat has demand, all tied into the board 24v transformer.
  • Zman
    Zman Member Posts: 6,452
    I sounds like you can use the SR506 per instructions to manage the heating zones.
    The issue is how do you manage the 24v diverter valve with a 120 volt pump relay when you get a hot water call? It is after all designed for a pump. I would suggest a relay with a 120 volt coil be wired to the priority pump terminal on the SR506. The low voltage side would be powered by the boiler transformer or by the one onboard the SR506.
    Any simple relay should handle it, perhaps one you already have...
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • dvizz
    dvizz Member Posts: 39
    The relay that is shown next to the WM control board is 24 volt. It is wired in series with the thermostats so the signal from the aquastat will send 24 volts to the 3 way to close and also turn on the boiler and circulator pump as would a signal form a room thermostat. I could replace it with a 120 v coil relay and have the indirect aquastat signal feeding term. 6 on the SR506 energize the relay. I could take the onboard transformer 24v and use that to power the 3 way through the relay. Does that make sense?
  • hot_rod
    hot_rod Member Posts: 14,552
    The Caleffi relay boxes have a dry end switch connected to output 1. The other two end switches are dry and enable with any call for heat. It may give you all the functions you need without adding additional relays or hardware.

    The remote enable is another unique feature that can be used to override ODR for example.






    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • Zman
    Zman Member Posts: 6,452
    If you haven't already purchased the Taco, Hot Rod's solution is simpler.

    If you go with the option I suggested a DPDT relay like this one gives you plenty of flexibility. http://tekmarcontrols.com/products/accessories/004.html

    Don't worry about the brand, most control companies make one.



    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • dvizz
    dvizz Member Posts: 39
    I want to combine the bedroom thermostat with the bathrooms. There are two seperate thermostat and two circulators. Don't know why it was designed that way but I don't see the benefit as their next to each other. Can I jump across the thermostat terminals on the SR506 and have two seperate pump outputs.
    Thanks
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