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Old Boiler Issue

ibook7537 Member Posts: 4
Hi guys,

I got home from work tonight and I noticed it was cool, 62F...the thermostat is always set to 68 during the heating season. I went down to the basement to check the boiler. The thermostat said 62. I have an older National brand boiler with B&G series 100 pumps, 2 zones. The boiler gauge was 35ish PSI and 180F. I didn't take a picture at first but the attached picture is about an hour later, after I hotwired the pump for one zone to run continuously. At first I turned the thermostat all the way down and then all the way up. I could hear a clicking noise coming from the basement. I incorrectly assumed that the pump on the main floor zone had died. I just so happen to have 3 spare pumps that came with the house so I figured I'd go ahead and swap the nicest looking one in. Still nothing. At this point I checked to see if the pump was getting power(I should have checked that before swapping the pumps out, it's 1am I just got home from work), it wasn't. I opened up the Honeywell RA832A relay box. I typed that into google and saw a post on here about someone else hot wiring the #2 and #3 terminals together and that is what I did. It appears that the thermostat(round mercury switch Honeywell) is turning the burner on when it calls for heat and off when it is satisfied. What I don't know is what to do at this point, is it the RA832A that is faulty...replace that and be done, or is there another component that would cause the relay not to work/turn the pump on.

I don't know if this matters but I want to include as much information as possible. The second zone is upstairs, I am in the process of renovating the house and have the thermostat turned off(down all the way). The bathroom on the second floor is on zone one(main level). The bathroom always seems to give off too much heat and no matter where I have the thermostat set on zone 2 it never turns on due to the heat from the bathroom on zone 1. I checked this when I first came home and the bathroom was very warm, I am assuming that the boiler was acting as a gravity system? Anyways I am not a plumber or heating technician. Everything I did was from other posts on this site and a general understanding that I have gained from owning the house for a little over a year. I know the boiler is very old and probably past it's expected life but I don't really think it's smart to replace it until there is a serious problem. My gas bills aren't that high so I don't see any reason to at this point if it's just a bad relay.

The relay was NOT buzzing. I could manually push the contact and the pump would NOT run, the gas WOULD start. The gas also ignited when the thermostat would call for heat. I believe that there are two RA832A's, one for each zone. I did not try to swap them because it's late at night. I have attached a few photos so if I am confusing hopefully that will clear it up.


  • ibook7537
    ibook7537 Member Posts: 4
    The yellow wire is the jumper to terminals #2 and #3 in the first image.
  • Jamie Hall
    Jamie Hall Member Posts: 23,442
    Wiring diagram would be useful...

    In most cases the setup is that the thermostat -- which you have checked and seems to be working (no reason why it shouldn't -- those things last forever) allows power to a relay, which then turns on the circulating pump. Can you power the pump directly?
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
    EBEBRATT-Ed Member Posts: 15,626

    I think #1 & #2 on the RA832A should have 120 volt power. T & T are your thermostat connections. The terminals to start the burner are X & X I believe

    #3 & #4 are the contacts to start the pump

    Power for the pump probably has a jumper from 1 to 3 on the relay.

    When the thermostat calls the contacts between x & x close to start the burner and at the same time the contacts between 3 & 4 close to start the circulator
  • STEVEusaPA
    STEVEusaPA Member Posts: 6,505
    I think you should bring in some help.

    First to check your pressure gauge to make sure it's operating correctly. At that psi, you should've popped your relief valve.
    Next to check you have the proper amount of water in the system, the expansion tank is ok (steel-not water logged, bladder type-not failed) and that the system is purged of all air.
    Then to check the components.

    You could use a Taco 502 and 2 better, less energy gobbling (and less expensive) circulators to replace the ones you have now.
    Also, just because a circulator is getting power and 'spinning', doesn't mean it's working. The impeller could be broken or the coupling could be slipping.

    There was an error rendering this rich post.

  • ibook7537
    ibook7537 Member Posts: 4
    So I took out the RA832A relay. One of the contacts was burned up. I replaced this with a new Honeywell RA832A and hooked it back up. Right now everything is working correctly.
  • SuperTech
    SuperTech Member Posts: 2,186
    > @ibook7537 said:
    > So I took out the RA832A relay. One of the contacts was burned up. I replaced this with a new Honeywell RA832A and hooked it back up. Right now everything is working correctly.

    Please address the pressure issue with the boiler that @STEVEusaPA mentioned. Your safety pressure relief valve should be opening up at 30 PSI, operation above that pressure is dangerous, as is operating without a working pressure relief valve. Unless you like explosions I would attempt repair or call for help.
  • unclejohn
    unclejohn Member Posts: 1,833
    The black arm is the pressure reading red is limit.