Welcome! Here are the website rules, as well as some tips for using this forum.
Need to contact us? Visit https://heatinghelp.com/contact-us/.
Click here to Find a Contractor in your area.

Heating woes Dunkirk vlt

Options
Mcmonster508
Mcmonster508 Member Posts: 19
edited December 2019 in THE MAIN WALL
I had a wall mount Dunkirk vlt gas boiler installed about 4 years ago, everything worked relatively( it kept popping error codes almost every night) but still did the job most of the time well up until last year when we had it serviced for the first time
Since that service was performed it hasn’t gotten a single error code but I have multiple issues that I can’t seem to diagnose

1. It short cycles(I think that’s it) it calls for heat and starts the ignition process by ramping the fan up to 58% and gradually decreasing to 1% and then restarts the ignition process... the issue is it doesn’t happen all the time and it does it on both zones and sometimes when dhw call is made(much less often though)

2 it is sometimes very loud and makes my pipes vibrate while running, when the fan is running over 34%. This is usually also making a weird sound when it’s cycling.

3. It foghorns 90% of the time when Calling for heat

I did a little research and saw that it could be my nest thermostats that could cause these issues but noticed that it’s only ones with yellow red and white wires and I only have red and white wires so I
Not sure this applies to me.

Any help would be insightful.
Thanks in advance

Comments

  • Zman
    Zman Member Posts: 7,573
    Options
    Has a combustion analysis been done?
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
    kcoppIronman
  • Mcmonster508
    Mcmonster508 Member Posts: 19
    Options
    > @Zman said:
    > Has a combustion analysis been done?

    It has. I don’t remember the results though. It was last year.
    starsix67
  • Ironman
    Ironman Member Posts: 7,379
    edited December 2019
    Options
    Short cycling could also be caused by micro zoning, but a Nest should never be used with modulating equipment.

    The noisy pipes could be a result of air in the system or from steam flashing in the heat exchanger.

    Fog-horning is caused by the use of CSST gas line and combustion being too lean.

    The things listed above are the general cause for these issues. You mileage may vary. Please note that, as is the case 95% of the time, they are all installer or tech issues, not the boiler.

    Please post some pics of the boiler and its near piping from far enough back to include everything so we can better see how your system is set up.
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
    DZoro
  • Mcmonster508
    Mcmonster508 Member Posts: 19
    Options
    > @Ironman said:
    > Short cycling could also be caused by micro zoning, but a Nest should never be used with modulating equipment.
    >
    > The noisy pipes could be a result of air in the system or from steam flashing in the heat exchanger.
    >
    > Fog-horning is caused by the use of CSST gas line and combustion being too lean.
    >
    > The things listed above are the general cause for these issues. You mileage may vary. Please note that, as is the case 95% of the time, they are all installer or tech issues, not the boiler.
    >
    > Please post some pics of the boiler and its near piping from far enough back to include everything so we can better see how your system is set up.

    Here are some pictures of the boiler and setup
  • Ironman
    Ironman Member Posts: 7,379
    Options
    That's a pretty good looking installation.
    Regarding the piping noise: make sure the internal ball valve is open so that your system is configured for p/s, not series.

    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
  • mattmia2
    mattmia2 Member Posts: 9,741
    Options
    Did you mention the errors to whoever did the service?

    Is the t-stat connection on that boiler even 24 vac, or is it designed for dry contact only?