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Honeywell RA832A thermostat relay loud buzzing

speedbird Member Posts: 21
edited December 2020 in Strictly Steam
Hi everyone, I have a hot water line (off our steam boiler) that feeds 2 toekick heaters in the kitchen. Not a huge fan of the design for many reasons, but it's how previous owners did it. Needless to say everything works well. 

That said, the RA832A relay makes a terrible buzzing sound when that kitchen thermostat calls for heat, and runs the circ pump. It's a 2004 model so maybe it's just time to replace it? I have a shop down in the basement and it drives me insane. 

An electrician told me it just put a piece of electrical tape over the particular piece that vibrates next to the coil. That seems to work but afraid it's interfering with operation, and it'll fall off eventually.


  • Solid_Fuel_Man
    Solid_Fuel_Man Member Posts: 2,646
    You need to check if you are getting 24+ volts to the coil. If you are and it still buzzes, replace the RA832. If not, find out where the voltage drop it. Transformer not making 24 volts (unlikely) long undersized thermostat wire...maybe....or poor contacts in the thermostat (R&W). 

    At least try jumping out the TT on the control and see if it still buzzes. Also, make sure you have 120 volts to the control, not something less. 
    Serving Northern Maine HVAC & Controls. I burn wood, it smells good!
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 7,829
    edited December 2020
    Honeywell is aware of this problem and addresses it in its instructions.

    here is the full instruction sheet: https://s3.amazonaws.com/s3.supplyhouse.com/product_files/RA832A1066-Install.pdf

    The noise is a normal byproduct of alternating current (AC) that sometimes makes a mild humming noise at 60 cycles per second (Hurtz). I will tell my customers that it's humming is because they forgot the words but, if the buzzing is too loud you can try adding felt or tape or any other vibration dampener that works. As long as it does not interfere with the operation of the mechanical parts of the relay.
    Edward F Young. Retired HVAC ContractorSpecialized in Residential Oil Burner and Hydronics
  • speedbird
    speedbird Member Posts: 21
    Able to confirm I have 120v coming into the control but cant seem to get a reading across the TT terminals. Reading 0v. I think I'll just tape it down for now and order a new one. I'll add those rubber washers this time around. 
  • Jamie Hall
    Jamie Hall Member Posts: 23,276
    I the thermostat is calling for heat, you should get 0 volts across the T-T terminals. That is correct. When the thermostat is off, then you should read at least 24 volts.

    If you can access the coil terminals of the relay, check the voltage with the thermostat calling. If it is less than 24 volts, there's your problem.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • speedbird
    speedbird Member Posts: 21
    Good call. 24v across TT. I know it was mentioned earlier too, any idea how I'd check voltage to the actual coil?
  • Tim McElwain
    Tim McElwain Member Posts: 4,621
    The truth is you will read around 15 volts across T T as you are including the resistance of the coil when you go across T T the remainder of the voltage is being dropped across the coil. If you read lower than 15 then the coil is dropping too much and the relay needs replaced.
  • speedbird
    speedbird Member Posts: 21
    Ok I'm reading 24v across TT when it's not calling for heat.