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Heats not moving

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2 weeks ago I replaced a gas fired hot water boiler. It had been broken and off for about a year before I got there. It’s for a single apartment on the 6th floor. On short notice I could only get an oversized burnham x2, customer didn’t mind the price difference. I installed it. Couldn’t get pressure upstairs. Replaced the 12-25 auto feeder with a Caleffi. Takes a while to get the system to 36psi. When I try to bleed air, the pressure drops, even with a bypass I loose pressures. I put an air scoop on the supply, xtrol 30 tank at 35psi. Taco 007 on the supply side. Thermostat works. The baseboards are not getting hot. 6th floor and about 60 ft offset from boiler room ceiling to when it rises upstairs. Heat is not circulating. Any ideas? 

I was thinking to wire the circulator directly so it runs 24/7. 

Comments

  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 8,060
    edited December 2022
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    Static pressure in the boiler MUST be over 25 PSI to get the water to rise to 60 ft above the gauge location. I might select 28 or 29 PSI on the gauge. Are you trying to purge the air out of the system by forcing the air out of the with a purge valve in the boiler room? You will need more that 30 PSI to entrain the air in order to force it all DOWN 60 ft.. Do you have a purge opening at the top of the system? (60 feet up from the gauge in the boiler room). That is how I would make sure to get all the air out. Open the valve at the top of the system to let all the air out the top of the system.

    That said, Did you order a boiler with a 50 psi or 45 psi maximum pressure rating so you can use a pressure relief valve rated higher than 30 PSI?

    Edward Young Retired

    After you make that expensive repair and you still have the same problem, What will you check next?

    Rich_49
  • pedmec
    pedmec Member Posts: 987
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    Like @EdTheHeaterMan said you need to make sure you have the system purged and the correct fill pressure. depending on the pipe size and length (volume of water) you might need to go to a extrol 60 too

    If that is OK then i would look at the circulator. What model circulator are you using and does it serve just the one zone.
  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 15,614
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    Sounds like your low on water pressure if you can't get the water up there with the bypass. you may have to fill it with a booster pump.

    But that makes no sense the 6th floor apt needs DW as well. Measure the height from the boiler to the top of the 6th floor radiation. (drop a rope out the window with a weight on it and tie a knot pull it up and measure that height) plus what you need to get to the boiler. devide the length by 2.31 to get psi and add 4 psi to that. That's what psig you need at the boiler. Also pressurize the expansion tank to that pressure and set the feeder prv to that pressure. 60' of rise would need 30 psi
    Rich_49
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 8,060
    edited December 2022
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    Here is an explanation of "STATIC PRESSURE" as I taught it in my classes
    Water has weight. just try lifting a 5 gallon bucket of it! We measure water pressure in pounds per square inch (PSI). So think of a stack of quarters. (about a sq inch). at the bottom of that stack is where to most weight of quarters is. half way up the stack, those quarters from that point up weigh exactly 1/2 of the weight of the full stack.

    Although you may have a 1000 gallon tank of water that weighs over 4 tons, any given square inch of that water will only weigh 1 pound for every 28" of hight in that tank of water. With that understanding we can move on the your building. and see how much water pressure is needed to get the water up to the radiators on the 6th floor.

    The pump that is needed to move that water uses the Ferris wheel principle. The weight of the water going up the supply pipe is offset by the weight of the water going down the pipe. so the pump does not need to be that strong. restated in pump terms the head pressure of the pump does not need to lift the water 60 ft. it just needs to overcome the friction of the pipes and fittings in the closed system. So your circulator pump can not overcome the weight of the water in the system if there is an air pocket in the system.


    This may illustrate what may be happening in your system. See the center diagram where there is just enough air to restrict the flow of heated water to a very small flow rate.




    This is one explanation, there may be others. To rule this on out, Get ALL the air out of the system

    Edward Young Retired

    After you make that expensive repair and you still have the same problem, What will you check next?

    MikeAmannDanielSkrela
  • DanielSkrela
    DanielSkrela Member Posts: 5
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    Thanks for the help so far gentlemen. So the boiler is rated for 50psi. I increased the relief valve to 50psi. I checked with US boiler, they said it was fine to do so. Upgraded the feeder valve. It takes a few minutes to see the gauge get up to 35psi. I had it set to nearly 40psi. The entire piping from what I can see is 3/4”. There’s also no purge valve at the top. Only baseboards that have been painted over. I tried to purge the system all through the basement. Currently using a taco 007e, the plastic body one. I was thinking of going with a taco 008. The old Cyril tank was a 10, I chose to go with a 30. The Cyril tank is pressurized a little less than system pressure. 
  • DanielSkrela
    DanielSkrela Member Posts: 5
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    Perhaps it’s only air blockage. I can’t be confident when I can’t purge the system. They do get water pressure to the apartment. But the boilers are fed separately from water heaters. No gauges on the building pipes. 
  • Steve_210
    Steve_210 Member Posts: 646
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    If it was me I would isolate Boiler and Power purge system With full mains pressure.
    hot_rod
  • DanielSkrela
    DanielSkrela Member Posts: 5
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    Just spoke to my helper that did the install with me. He told me he didn’t add the integral check into the circulator. Now I’m thinking that high zone is being overcome by gravity flow, I’m not sure how that would affect the taco007e
  • Jamie Hall
    Jamie Hall Member Posts: 23,428
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    That pump doesn't have the capability of raising the water that high. If ALL the air is out of the loop it can circulate it, but if there is any air in the top of the loop it can't. Until you get all the air out with something like @Steve_210 's suggestion up there, you'll never get circulation.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
    DanielSkrela
  • DanielSkrela
    DanielSkrela Member Posts: 5
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    I’m considering bringing 100ft of hoses tomorrow so I can connect it to the building main and try to power purge it. 
    hot_rod