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24 Volt AC indicator lights

Andy5000 Member Posts: 2
Hi All - My boiler system has three zone valves, powered by 24 volts

AC. I am looking to rig up a indicator light inside my home to show me

which zone is currently calling for heat. My thermostats do not have

any lights on them.

I thought of two ways of doing this and am looking for advice on these or perhaps another suggestion.

1) Attach a relay that is powered by 24 VAC to each of the zone valves

on the zone valve power leg, not the end switch leg. Then build a

simple DC circuit on the switched side of the relay to light an LED in

my house.

2) Light an LED for each zone directly from 24 VAC using a circuit like the one in the link below.

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The second option would be cheaper to implement, but I'm concerned that

extra resistance added into the 24 VAC circuit might somehow interfere

with the proper operation of the zone valve.

Any thoughts or ideas are welcome. Thanks!


  • Mike Kusiak_2
    Mike Kusiak_2 Member Posts: 604
    Led indicators

    Lighting the indicator led directly from the 24VAC feed to the zone valve actuator should be no problem. Using the combination of the 1K resistor, rectifier diode and Led as in the center circuit diagram should work fine. Just remember to connect the indicator circuit in parallel with the valve actuator, not in series with it.
  • Andy5000
    Andy5000 Member Posts: 2

    Thanks Mike,

    To make life easier, I ordered three of these.  They already have the diode and resistor built in.  Should work well!
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