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aqua stat

DaveM
DaveM Member Posts: 53
in Domestic Hot Water
Is it ok to use a honeywell L4080B on a indirect storage tank to be used in conjunction with a taco 007 circulator connect to a taco sr503 relay control if so a wiring diagram would be a great help Thanks

Comments

  • DaveM
    DaveM Member Posts: 53
    just trying to understand , low limit, high limit, break on rise, low voltage, line voltage etc
  • STEVEusaPA
    STEVEusaPA Member Posts: 6,505
    Why?
    Indirect should have an aquastat sensing internal temperature which will initiate a call for that zone either thru a zone valve or it’s own circulator.
    What is your setup of controls and components?

    There was an error rendering this rich post.

  • DaveM
    DaveM Member Posts: 53
    Steve I have an oil fired hydronic boiler with a L7248 triple aqua stat control with two heating zones using circulators connected to a taco sr503 relay I'm removing the old tankless coil and installing a superstor indirect storage tank thanks for your help
  • STEVEusaPA
    STEVEusaPA Member Posts: 6,505
    The main question is how is the 503 wired to the 7248? Basically you'll use T-T on the 503 to the aquastat on the indirect. You can set it up for priority.

    There was an error rendering this rich post.

  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 9,378
    edited April 2022
    STEVEusaPA said:

    The main question is how is the 503 wired to the 7248? Basically you'll use T-T on the 503 to the aquastat on the indirect. You can set it up for priority.


    If you look at the rating on the control instruction sheet, you can see the control with a designation of L4080 has switch contacts rated to operate at 240 volts or 120 volts or 24 volts of the alternating current variety and from 1/4 of a volt to 12 volts of the direct current variety. The same design control can have a model number of L8080 where the contacts are rated for low voltage only... as low as 750 millivolts.


    Since the aquastat does not create voltage, you can use the L4080 for a 24 volt AC or a 120 Volt AC circuit.

    Also the L6006 control that Dave already owns, can do the same job. So Dave, Don't get rid of that control. It has the same working parts inside and can fit on the same well adaptor inside the indirect tank

    Edward Young Retired

    After you make that expensive repair and you still have the same problem, What will you check next?

  • HVACNUT
    HVACNUT Member Posts: 6,329
    Also the L4080B is a Limit, Normally Closed, break on temperature rise operating control. It has an internal fixed differential. Just wire it low volt from the aquastat to TT or RW on the SR503. XX on the 503 to TT on the L7248 IF the L7248 offers condensate protection or it's a steel boiler. You can set the low side to off. Otherwise (I'm guessing) leave it wired using ZR,ZC and set the low to no less than 140°.
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 9,378
    edited April 2022
    There are other aquastats that will also work. Honeywell has several types of HVAC controls currently in use today. Series 80 controls can only be used for low voltage. For example the T87 thermostats are a 2 wire switch for heating only use. (The 3, 4, and more wire models are for combination heating and cooling or heat pumps). The L8080 aquastat is used for low voltage and millivolt gas valves. There are series 40 controls that have contact ratings for Line voltage like 120 VAC that can be used on circulator pumps OR low voltage (24 V.) controls. L4006, L4080 and L4081 controls can all be used for 24 Volts or 120 volts. The control does not make electricity change to the rating on the side of the control. As many have said before, Electric is colorblind... now I can add Electric can't read either.

    Edward Young Retired

    After you make that expensive repair and you still have the same problem, What will you check next?

  • DaveM
    DaveM Member Posts: 53
    thanks for the education boys. Did plumbing all my life, I find wiring and learning about different controls so interesting
  • DaveM
    DaveM Member Posts: 53
    hvacnut you bring up a good question when I set the storage tank aqua stat to 140 degrees as priority for dhw do I set the low limit on the L7248 control to off and keep the hi limit to 200 as it is now
    by the way the L7248 does not have a ZC terminal I will be connecting the L4080B to the sr503 on the RW zone 3 priority and XX to TT on the boiler control(L7248) is this correct Thanks again for all your help
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 9,378
    DaveM said:

    hvacnut you bring up a good question when I set the storage tank aqua stat to 140 degrees as priority for dhw do I set the low limit on the L7248 control to off and keep the hi limit to 200 as it is now
    by the way the L7248 does not have a ZC terminal I will be connecting the L4080B to the sr503 on the RW zone 3 priority and XX to TT on the boiler control(L7248) is this correct Thanks again for all your help

    Correct


    Edward Young Retired

    After you make that expensive repair and you still have the same problem, What will you check next?

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