Boiler Problem

Discussion in 'Boiler Forum' started by jc60618, Dec 13, 2009.

  1. jc60618

    jc60618 DIY Junior Member

    Messages:
    88
    Location:
    Chicago
    Am having a problem with my boiler. Its in a duplex house and it feeds cast iron radiators in the second floor only. The boiler fires up OK put the radiators dont get hot, just warm. In the basement the supply pipe is hot but the return lines are just warm. Ive checked the aquastat relay box and the temp in there is set to 180 (low) 200 (hot). Also the pump and reducing valve was changed two weeks ago. Can the problem be the circulation pump? How do I know if its working correctly? When the pump was installed I could feel the water reciculating in the pipes but not anymore. Is the boiler just heating up standing (convection) water and thats why the radiators dont get hot?. The pump is a series Taco 005 pump.
  2. johnjh2o1

    johnjh2o1 Plumbing Contractor for 49 years

    Messages:
    1,143
    Location:
    South*East
    It sounds like you have air in the system . Have you tried bleeding the radiators?

    John
  3. jc60618

    jc60618 DIY Junior Member

    Messages:
    88
    Location:
    Chicago
    Whats the best way to start? Should I go to each radiator and bleed them out for a couple of minutes?
  4. johnjh2o1

    johnjh2o1 Plumbing Contractor for 49 years

    Messages:
    1,143
    Location:
    South*East
    Just do one at a time. Open the vent on each radiator until you get water.

    John
  5. jc60618

    jc60618 DIY Junior Member

    Messages:
    88
    Location:
    Chicago
    Before I bleed the radiators I checked if the radiators were hot, five out of seven were indeed hot. I bleed them any way and I got a little air out of one, the rest water came out right away. Ive included an overhead drawing of the piping. Can the problem be with the pump is it "air locked" because I dont feel any movement in the return piping by the boiler.

    Attached Files:

    Last edited: Dec 13, 2009
  6. johnjh2o1

    johnjh2o1 Plumbing Contractor for 49 years

    Messages:
    1,143
    Location:
    South*East
    Turn the thermostat down then bleed the radiators. This will allow the air to go to the high points of the system which will be the radiators. You will not feel any movement in the return piping at the boiler.

    John
  7. jc60618

    jc60618 DIY Junior Member

    Messages:
    88
    Location:
    Chicago
    When I turn the thermostat down should I wait for the system to cool down before bleeding the air out.
  8. johnjh2o1

    johnjh2o1 Plumbing Contractor for 49 years

    Messages:
    1,143
    Location:
    South*East
    No, just bleed the radiators.

    John
  9. Doherty Plumbing

    Doherty Plumbing Journeyman & Gas Fitter

    Messages:
    810
    Location:
    Penticton, BC
    Sounds to me like your circ pump is acting up. If you don't have any leaks i the system or have never had any problems with air before I doubt it's air.
  10. johnjh2o1

    johnjh2o1 Plumbing Contractor for 49 years

    Messages:
    1,143
    Location:
    South*East
    He stated he replaced the cir. and the auto feed two weeks ago. That is more then likely where the air came from.

    John
  11. Doherty Plumbing

    Doherty Plumbing Journeyman & Gas Fitter

    Messages:
    810
    Location:
    Penticton, BC
    Ooops sorry sometimes I read through the posts so fast I miss those little tid bits of info :D

    My bad.
  12. jc60618

    jc60618 DIY Junior Member

    Messages:
    88
    Location:
    Chicago
    Thanks guys I think that solved my problem. I have heat on the two radiators now. By the way how can I tell if the pump is doing its job. The manufacturer of the pump says its real quiet when operating. Also what are some of the common malfuction of circulation pumps. Can something get caught in the impeller preventing it from moving? Finally what does the impeller "spin" is it water or steam? I have gotten different responses from two heating guys?
  13. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    22,021
    Location:
    New England
    It sounds like your system is hot water...if it had steam it wouldn't need a circulator. So, the circulator is moving water.
  14. nhmaster

    nhmaster Master Plumber

    Messages:
    3,189
    Location:
    S. Maine
    You can usually hear the circ running. Is it installed with the direction of flow correct? Is it wired correct? If it's running, you have an air problem or not enough pressure. Pressure should be 12 - 18 lbs
  15. rmelo99

    rmelo99 Network Engineer

    Messages:
    349
    Location:
    Connecticut
    My system has many circulators and it was tough to tell when a pump was running. They make a slight humm. I was told to take a screwdriver and touch it to the pump and my ear and the sound would be much louder.

    Now that just tells you the motor is running, doesn't necesarrily mean it's working!
  16. Doherty Plumbing

    Doherty Plumbing Journeyman & Gas Fitter

    Messages:
    810
    Location:
    Penticton, BC
    You can usually tell the difference from a motor that's not working and one that is. Not to mention a circ pump that is not working will be VERY hot to the touch (IE hotter then the water in the system). Unless of course it's an older style oiled circulator. But seeing how it's new I doubt it.

    It's possible the impeller is clogged up with sediment from within the piping system. You might be best to pull the pump once again and check the impeller if you think your pump is acting up. If the impeller looks fine then turn the pump on so you can make sure the impeller is spinning.
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