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    R845A RELAY (12 Posts)

  • Dick Charland Dick Charland @ 8:20 AM
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    If you take a pair of needle nose pliers or tweezers you can disconnect the spring on top of the clapper and take a good look at the contacts. If they are pitted etc. time for new relay. I concur, check the amp draw on circulator, this usually does not happen out of the blue, could have been building up for some time.
  • Joe Mattiello Joe Mattiello @ 7:48 PM
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    If the C1,C2 terminals are stuck closed, you can simply use a SR501 switching relay to energize the pump, and save some money.
    joe mattiello
  • zeke zeke @ 4:33 PM
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    quote"you stated when you turn off the power, the relay opens or is de-energized.if the contacts were stuck or fused closed . the contacts wouldn't open. might want to check the lo-voltage wiring for a short or maybe a bad tstat. just a thought before you change the relay" Would most definitely agree that it is the thermostat. No other way can you free the contacts by cutting power. Contacts are OK.To verify this theory, try removing the thermostat wiring to the thermostat and jumper the R to the W wires out of the wall. They should cause the relay to activate etc and after the water heats up and then the circ pump should go on. Then separate the two wires. That should kill the power to the relay and stop the circ pump. I think it will,and therefore prove that it is the tstat.
  • ROB ROB @ 7:07 PM
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    R845A RELAY

    I HAVE A HONEYWELL R845A SWITCHING RELAY ON MY BOILER WHICH CONTROLS A CIRCULATING PUMP.IT HAS WORKED FINE FOR APPROX 5 YEARS.I HAD TO KILL THE POWER TO THE BOILER RECENTLY AND NOW THE CONTACTOR STAYS CLOSED ALL THE TIME WHEN THE POWER TO THE BOILER IS ON,CAUSING THE PUMP TO RUN CONSTANTLY. I TRIED DISCONECTING THE STAT WIRES BUT THE CONTACTOR STILL REMAINS CLOSED.ANY HELP WOULD BE GREATLY APPRECIATED,THANKS ROB
  • mtfallsmikey mtfallsmikey @ 6:54 AM
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    845

    Still available...
  • ROB ROB @ 6:22 PM
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    I AGREE, ITS TIME TO REPLACE THE RELAY. I DONT THINK THE CONTACTS ARS ARC WELDED BECAUSE WHEN I TURN THE POWER OFF THEY RELEASE.THANKS FOR ALL YOUR RESPONSES,ROB
  • Leo Leo @ 9:23 AM
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    More Questions

    He said he had to "kill the power to the boiler recently". Why was that? Could be therein lies the problem. Leo
  • Bruce Stevens Bruce Stevens @ 7:27 PM
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    Time to replace

    with a Taco SR501
  • dana dana @ 6:59 PM
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    relay

    you stated when you turn off the power, the relay opens or is de-energized.if the contacts were stuck or fused closed . the contacts wouldn't open. might want to check the lo-voltage wiring for a short or maybe a bad tstat. just a thought before you change the relay
  • radioconnection radioconnection @ 7:14 PM
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    Stat wires

    Did you disconnect the stat wires right at the T T terminals on the Honeywell relay?
  • Glenn Sossin Glenn Sossin @ 10:59 PM
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    contacts

    Your contacts on that relay probably arc-welded closed. This could be an indication of an excessive amperage draw from your circulator so just simply replacing the relay may be a short term fix. The contacts are accessible on that relay, they are not sealed. You can try taking a matchbook cover and slide it in between the contacts to open them up and to help try and clean them - keep them functioning a little longer. Don't use an emery board or anything abrasive. Agree with Bruce, it may be time to replace with a more modern relay that uses a cartridge with sealed contacts like the Taco or an Argo AR-822. Either relay will be an acceptable substitute. The typical home heating circulator draws under 1A. If you know how, you may want to use an amp meter to check the current draw on the circulator. That might me the underlying cause of your problem. Good Luck
  • Dave Dave @ 11:23 AM
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    Stop pump

    It would appear that he killed the power to stop the circulator pump. If the contacts were welded closed, he the circulator would be getting power regardless of whether there was a call for heat.
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