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Boiler relay help

karter
karter Member Posts: 9
in THE MAIN WALL

need some help.fighting a boiler pump. Have a honeywell r19a relay to a honeywell t8400c dig thermastat has been working ok but can turn it up or down and does not make relay close.i can manually close contacts and pump works bg100.how do I test. And how to jump relay to test it.on my dayton 2 wire relay i just jump the 2 therm wires and relay fires.but not shure o the 3 wire r19a. Have white red blue wires to therm. Also where do I find a r19a relay for a spair.also need a dayton 2e143 relay cant find it also .thanks also are the r19a dpst relays

Comments

  • karter
    karter Member Posts: 9
    20241103_163201.jpg

  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 16,283

    R19 is a three-wire thermostat control. Those relays are no longer made. I would replace it with a RA89A Honeywell relay.

    But if you connect two wires from your thermostat R on the thermostat to R on the relay and W on the thermostat to W on the relay it should work. Don't connect anything to Blue on the relay.

    HVACNUT
  • karter
    karter Member Posts: 9

    Did you look at pictures its been running like this for 2 years.if the blues hooked up at relay and not at thermostat hurt telay.if I take a jumper wire on relay to w and r should it fire

  • karter
    karter Member Posts: 9

    Trying to determine if I have a bad relay or thermostat

  • 109A_5
    109A_5 Member Posts: 1,472

    Starting a page 9 it has an explanation that includes the R19a relay.

    http://www.hvac.amickracing.com/Controls/Heating%20Control%20Handbook-Honeywell.pdf

    National - U.S. Gas Boiler 45+ Years Old
    Steam 300 SQ. FT. - EDR 347
    One Pipe System
  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 16,283

    If you have 120 volt power into the relay and with the thermostat wires disconnected jump "W" & "R". The relay should pull in if it doesn't it's bad.

    When it pulls in the relay contacts should close and whatever is connected to the relay contacts should start

  • karter
    karter Member Posts: 9

    On the r19a relay does enyone stock parts to rebuild them.what about sig Harvey people.

  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 16,283

    @karter

    You're talking a relay that is probably over 60 or 70 years old. No one will have parts to rebuild it. Just buy a new relay.

    ScottSecor
  • HVACNUT
    HVACNUT Member Posts: 6,238
    https://forum.heatinghelp.com/discussion/comment/1821330#Comment_1821330

    Sid Harvey's isn't open to the public. Get a Taco SR501 and be done with it.

    Can you show the thermostat and the wiring at the sub base? I'd be shocked if it's still Series 20.

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