Wiring taco sr504 exp

kramer56

Ok so built a house in 2013 and I have a propane Weil McLain CGI boiler installed and I used an outdoor wood boiler until a week ago I installed a Weil McLain aqua plus 45 and want to shut down the wood boiler, mostly for insurance problems. My contractor installed everything except the new indirect water heater. He used a taco sr504exp. My question is how do I wire this new dwh to turn the gas boiler on and do it correctly? Right now I have it running but not correct because it kicks on when call for hot water but boiler shut off once the boiler water reaches dwh set point. Then kicks right back on until it is fully satisfied. I know I'm missing something very obvious. On the sr504 there is no jumper on the zr zc contacts either, should there be? The boiler pump does kick on for a call for heat. Does anyone have a simplified wiring drawing, I'm fighting my brain trying to figure out what diagram to use and it's just not working properly

HVACNUT

Are you able to wire into the SR504, or the indirect needs it's own switching relay?

kramer56

I put the pump on zone 4 in the sr504 which it says it's priority.

kramer56

The aqua plus has a small digital control that needs power from somewhere and has 2 outputs that need to be going to the right place. Right now from boiler it goes from r,c to the dwh control inputs, then from the control outputs to the sr504, but when dwh calls for heat everything kicks in but boiler will not go above the setpoint of the dwh control even tho I have boiler set to 180.

HVACNUT

No jumper between ZC and ZR.

Output contacts on the AcuTemp to R and W on the 504, zone 4 (priority).

AC1 and AC2 on the AcuTemp to C and R respectively (AC1 shows ground so that's the Common) on the 504, zone 4.

If I'm reading right, you're only using 2 wires. You need at least 3. You can jump one of the output contacts to AC2.

kramer56

Right now I'm using 2 wire from boiler red and black ( c) to the dwh control inputs, white is ground. Then 2 wires to r, c on the 504 zone 4 from the outputs of the dwh control. Nothing is jumped

kramer56

> @HVACNUT said:
> No jumper between ZC and ZR.
>
> Output contacts on the AcuTemp to R and W on the 504, zone 4 (priority).
>
> AC1 and AC2 on the AcuTemp to C and R respectively (AC1 shows ground so that's the Common) on the 504, zone 4.
>
> If I'm reading right, you're only using 2 wires. You need at least 3. You can jump one of the output contacts to AC2.
>
>
>

Are you saying to have also 2 wires leaving the Ac1 and Ac2 input screws going to the r,c on zone 4 in sr504? Or should that be coming from the the outputs of acutemp to the 504?

kramer56

Do I connect anything to the blue dwh wires on my boiler or leave the boiler out of it?

HVACNUT

I would contact WM about that or maybe someone here is familiar with the CGi. I see a low volt connection for DHW on their control but no relay or separate line volt output for a DHW circulator. That doesn't make sense to me. I didn't read the manual thoroughly but I didn't see any reference to DHW other than "connect here".

In the meantime, do as above and turn off the economy settings and see what that does. Set limit to 180°.

I do not like the CGi wiring diagram. You cant see inside the control module. Everything just plugs in.

Have your manual in hand if you contact WM and let us know what they say.

kramer56

Would it help if I powered the acutemp ac1 and Ac2 by the main end switch on the top left corner of the sr504 instead of the red and black wire coming from boiler control then run the outputs back to the zone 4? Why do I jump Ac2 to one of the outputs?