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Hydrostat 3250+ and Taco SR 504-EXP settings.

Rickoo
Rickoo Member Posts: 28
I have a Peerless WBV boiler. Four circulators. Two for baseboard heating zones, one for a basement unit heater and one for a 45 gallon indirect water heater. Each zone is piped independently.

I’m wondering what the best settings would be for my setup.

This is how the Hydrostat and SR 504 are wired except there is NO jumper between ZC/ZR on the SR 504. The diagram doesn’t show L1/L2 connections on the relay but they are wired.





My inclination is to set it up as below:

Hydrostat 3250+:
Hi Limit: 190. (Default)
Low limit: OFF. (Default)
Economy Feature: 2.
Thermal Pre-Purge: ON.
Low Level Cut-Off: AUTOMATIC. (I have the Electro-well installed)
Circulator Activation Options: Circulator on TT calls only.
Hi Limit Differential: 10 degrees. (Default)


Taco SR 504-EXP dip switches:



Any suggestions on these settings?

Comments

  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 5,632
    Looks like it should work just fine. Are you experiencing any issues?
    Edward F Young. Retired HVAC ContractorSpecialized in Residential Oil Burner and Hydronics
  • Rickoo
    Rickoo Member Posts: 28
    No, this is a new install of the indirect and the unit heater. The hydrostat and SR 504 were also added.

    Haven't powered it up yet. Just finishing the install and was wondering about my choice of settings.

  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 5,632
    Are you sure you need the blue wire from ZC on the SR504 to C1 on the Hydrostat?

    Wont the ZC ZR jumper do the same thing?
    Edward F Young. Retired HVAC ContractorSpecialized in Residential Oil Burner and Hydronics
  • Rickoo
    Rickoo Member Posts: 28
    All circulators are operated through the SR. I wanted to use circulator hold off and being that there was nothing connected to C1/C2 of the 3250, I wondered how this could work. I read in another thread that the C1/ZC connection would do it. Called Hydrolevel and they confirmed that. I found it interesting that the EXP version of the SR504 doesn't come with a ZC/ZR jumper. I believe the standard SR504 does. Not quite sure why?
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 5,632
    I would need to research this but, I believe that the post purge function of the SR504 may not work if the circulators are being powered by the C1 of the 3250. That is because the XX of the SR504 will open if there is no call for heat. Once the XX opens and the TT on the 3250 is no longer in a "call for heat" mode, the C1 will no longer have power to operate any circulator thru the ZC on the SR504. If you want the energy saving of the post purge feature, you will need to have power to the circulators by some other source. ZC to ZR jumper provides the other power source
    Edward F Young. Retired HVAC ContractorSpecialized in Residential Oil Burner and Hydronics
  • HVACNUT
    HVACNUT Member Posts: 5,026
    I would need to research this but, I believe that the post purge function of the SR504 may not work if the circulators are being powered by the C1 of the 3250. That is because the XX of the SR504 will open if there is no call for heat. Once the XX opens and the TT on the 3250 is no longer in a "call for heat" mode, the C1 will no longer have power to operate any circulator thru the ZC on the SR504. If you want the energy saving of the post purge feature, you will need to have power to the circulators by some other source. ZC to ZR jumper provides the other power source
    Yes, the OP should turn off the post purge in the Taco and activate the pre purge in the Hydrostat. 

    Also, I would set the limit to 160° and economy to 3. If the boiler doesn't keep up with demand, it can always be adjusted. 
  • Rickoo
    Rickoo Member Posts: 28
    Will make those changes. Thanks.