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Air lock? Circulation problem today...

Post in 'The Boiler Room - Wood Boilers and Furnaces' started by Gilby, Dec 30, 2012.

  1. Gilby

    Gilby Member

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    So recently i had my two circ pumps wired to their own controller - independent of the boiler and the thermostats. I also had the near boiler pump wired independently until i can get a new controller. once i had this done I've had zero problems. obviously my controller has been my number one issue the past 12 months. everything was working perfectly for the first time in a year...until last night. i'm getting a ton of hot water to my first pump...but the return off that furnace is cold...which leads me to believe there is a bubble hanging out somewhere in the coils within the furnace. hot going in...nothing coming out. the second pump is getting no hot water at all. its almost like theres a bubble in the 8" of pipe between the two pumps. occasionally i'll get a little but as soon as the furnace turns on, everything gets cold. this confuses me because the furnace turning on has nothing to do with my hot water circulating. the only thing that has changed in the past week since i had the pumps wired is i changed my well tank filter, which requires me to shut my water down. I'm guessing when i turned it back on, i got air in my boiler system. i should have turned that water off prior to my house so it doesn't push the air...now i know for next time. i have jacked with all three of my pumps at this point - on/off on/off - opened ball valves and closed them...doing anything to try to push water past the blocked spots....it'll work for awhile then get cold again. any suggestions?? naturally this doesn't happen until it's -20 outside tonight. not sure what to do. ive spent all day trying to get my water to stay hot heading in all directions. I've never had this happen before - at least not where 24 hours later i'm still dealing with it.

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  2. Gilby

    Gilby Member

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    frustrating....when both furnaces are off, i get hot water to flow through both pumps and the coils are hot - both coming and going. as soon as a furnace turns on, my hot water stops and i have cold pipes. that has NEVER happened before. the boiler itself is idling and maintaining temps. haven't hardly heard the fan kick on once today and have used minimal wood. my wood is dry. boiler temps been hovering at 174 all day and night. i don't think it has anything to do with carrying a load. the furnaces should have nothing to do with those pumps next to the boiler. why is my hot water disappearing only when the furnaces are calling for heat???? not sure how air blowing over hot coils would affect an air lock? does the cool air impact an air lock within those coils? expanding/contracting? might be a dumb thought but i'm about out of ideas.
  3. huffdawg

    huffdawg Minister of Fire

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    Can you hook up a hose to purge the heat exchangers
  4. huffdawg

    huffdawg Minister of Fire

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    Also do you have hose bibs on both sides of your pumps . If so hook up a hose on the suction side of your pump and try to push water right through to the return side of your heat exchangers. Pumps could be airlocked. They could push enough hot water to make your pipes feel hot but not enough when furnace is demanding heat
  5. Gasifier

    Gasifier Minister of Fire

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    Any progress Gilby?

    The last time I thought I had an airlock above my oil boiler it turned out to be the pump above oil boiler was not getting any power. Control panel was not sending power to it. Put new control panel in, problem solved. And before we changed the control panel you would swear you could hear the pump running. Could there be some sort of change in electricity when your furnace turns on that could be changing what happens to electricity to your pump? You said the same system was working fine before when furnace was turning off and on. So was mine. Then apparently the main board in the control panel went bad. Don't ask me why.? ;hm Luckily I had a spare on hand. Let us know what happens.
  6. Gilby

    Gilby Member

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    i let the boiler burn out this morning. i've never purged it before. I don't have the hose bibs near the pumps....but there is a "spicket" if you will at the bottom rear of the return on the boiler. if i opened that and let water drain, do i run the risk of damaging anything? will it affect the air separator at all? it's a closed loop system so i leave the water on all the time....always maintains about 12 psi while the boiler is hot or cold. just wondering if i can't drain water out the rear of the boiler while it fills and get the air out? or do i need the pressure of a hose pushing water to get the air out? If i drain it like that, do i need to do anything in particular when restarting the boiler?

    Gasifier... thats a good point. the electrician was just here a week ago to rewire those. i can't imagine something woulda went haywire that quick, but you never know. its weird...the hot water will be there and then it's not. I'd think you may be right, but the other furnace is getting all the hot water...and the return hose is ice cold. it's still heating the house, but no hot water is getting back to the boiler. since it's happening all at the same time, i'm guessing it's air.
  7. maple1

    maple1 Minister of Fire

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    Most of the time air bubbles get stuck somewhere - usually a high point. The problematic ones won't move by just draining water - the air bubble will just stay where it's at. These are times when lots of isolation valves & drain/fill points come in very handy. Isolate a short section & purge at higher pressure with a garden hose is sometimes the only way to get stubborn air out. For a section that has frequent problems, a drain valve at the highpoint is worth its weight in gold - just crack it until the air comes out and things should get moving. I would cut in a drain valve if this happens very often.
  8. huffdawg

    huffdawg Minister of Fire

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    Do your heat exchangers have bleed valves on them? If they do hook up hose to that spigot and try to push the air out of the exchangers . Isolate your boiler,storage, and any other loop that is working properly.
  9. woodsmaster

    woodsmaster Minister of Fire

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    Do you run 12 psi or more on system pressure ?
  10. Gilby

    Gilby Member

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    also is at 12 psi for pressure.
  11. Gilby

    Gilby Member

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    will those bubbles pass on their own at any point? or will they just stay until i apply a form of pressure to push them out? i don't know enough about the whole system to hook a hose up and turn it on! scared i'll blow something out or break something!
  12. huffdawg

    huffdawg Minister of Fire

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    Post a diagram. With all the valves. we might be able to help.
  13. Gilby

    Gilby Member

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    Ok...sorry for the delay. I think I have a bad pump. I took the pump off and turned it on. There was a bit of water in it and it swirled around...but everything else on my entire system is working no problem. I can get hot water to my second furnace, but as soon as I turn the furnace on, I lose my hot water. I think the hot water I'm getting is ghost flow from the pump next to it. I'm contemplating picking up a new pump in about an hour. Plumber says the Taco 007. Hate to spend $160 when I'm not positive that's my problem.... but I just can't imagine it's anything else at this point. I get hot water all the way through until the furnace turns on. The water isn't keeping up with the demand...but it is on the other pump 8" away.
  14. Fwiw you should be able to pick up a 007 for ~ $80 at any lowes or home depot.
  15. kopeck

    kopeck Minister of Fire

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    All you should need is a new cartridge I would think. That should be under 100 bucks.

    K
  16. maple1

    maple1 Minister of Fire

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    Grundfos 15-58's are also under $100.

    If you can swap out what's not working with new though (cartridge?), it would avoid you having to unbolt the circ body from the piping.

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