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Boiler is gurgling and wont run

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MY boiler is making a loud bubbling or gurgling noise and will only run for a minute before shutting down. Video attached. Can anyone

https://drive.google.com/file/d/1uSFzmEAxqcNAB794NSUf9RQGjEFiIGpM/view?usp=sharing suggest what is the issue to suspect here?

Comments

  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 11,580

    Can't see your video without access

    Edward Young Retired

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

  • Grallert
    Grallert Member Posts: 1,038

    Sounds like there's not enough water indoor boiler. What's your gauge say? and is it working. When you open the PRV is seems you're cooling the heat exchanger.

    Miss Hall's School service mechanic, greenhouse manager, teacher, dog walker and designated driver

  • tousky8172
    tousky8172 Member Posts: 4

    Hello Grallert, THank you for the assistance. I do not believe the gauge works , as it never fluctuates at all and seems unresponsive. How can I estimate if I have enough water in the boiler?

  • mattmia2
    mattmia2 Member Posts: 15,638

    if you posted some pics that would help. is this a hot water boiler or steam boiler? is it a conventional boiler or a mod con?

  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 11,580
    edited November 10

    From the video

    Screenshot 2025-11-10 at 3.22.28 PM.png

    I think this is a copper water tube boiler?  …and it sounds like it is kettling from lack of water flow thru the Copper HX.   Probably want to get a pro in there to determine if the circulator is not operating or if the system is just air bound or is there a blockage keeping the water from moving freely thru the system. 

    Edward Young Retired

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

    mattmia2Joannie
  • mattmia2
    mattmia2 Member Posts: 15,638

    water tube boilers do not like lack of flow. In fact I think laars requires a bypass in the near boiler piping.

    Joannie
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 11,580

    @tousky8172 asked: "How can I estimate if I have enough water in the boiler?"

    Are there any vents at the top of the system? at the highest radiator? Open a vent upstairs and see if water comes out. If you get air then you may not have enough water in the system.

    Another way is with a pressure gauge that landscapers use to check water pressure on sprinkler systems. You attach the gauge to the boiler drain and open the drain valve to release the water pressure to the gauge to see whet the pressure is Water pressure gauge

    Edward Young Retired

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

  • hot_rod
    hot_rod Member Posts: 26,625

    did it start suddenly or over time. When they scale up the HX that is usually over a few years, noise increasing.

    If it started one day, air, plugged strainer, circulator impeller plugged or broken.

    Get the fill pressure up above 10 psi, then a good air purge are the simple first steps.

    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • tousky8172
    tousky8172 Member Posts: 4
    edited November 10

    Edtheheaterman, i opened this vent ( i believe it is what you mean. No air released, only water.

    1000006894.jpg
  • tousky8172
    tousky8172 Member Posts: 4

    Hot rod, this has been happening intermittently over the last 10 years. Would come and go. Sometimes not arise at all for a whole year. Would always go away. Now, it is wanting to stay this way.

  • hot_rod
    hot_rod Member Posts: 26,625

    there are some treatments for copper boilers that you inject and leave in. It cleans and keeps particles in suspension. Silver King was one brand. They have a nice hand pump also.

    IMG_1268.jpeg


    I prefer to run a cleaner, flush, refill and add a conditioner. I like to see the crud flush out.

    If air is purged out, and pressure is adequate, based on age, dirty heat exchanger tubes are common in that type of boiler.

    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
    EdTheHeaterMan