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.

system 2000

chapchap70_2
chapchap70_2 Member Posts: 147
The vessel restriction through the heat exchange area should be less than .05. In other words, if the draft at the breech is -.09, an over fire draft of less than -.04 probably means the boiler and/or chimney base needs to be cleaned.

I've seen one of those boilers fired at -1.00 at their factory so in all but the most abnormal cases, the draft does not need adjusting.

Comments

  • Hollis
    Hollis Member Posts: 105
    system 2000

    In checking the draft, is there a way to check it over fire as well as the exhaust pipe? Do you know what it should be?

    Also doesn't the draft depend largely on temperature differential? shouldn't you wait for cold weather to set it. AND I see that they don't usually recommend a a draft regulator. So how is this regulated if at all?
  • Jim_139
    Jim_139 Member Posts: 61


    On all but the oldest systems there is at least a 1/8" plug on the front cover that is removed to check draft over fire. On systems with a puff switch the plug is in the tee that the puff switch tubing is connected to. Set the CO2 at the overfire port to 10-11% and it doesn't matter what season it is when you do it. The specs call for negative draft, no specific amount, but hopefully at least -.02".

    Yes the draft does depend on temp differential but again, if the CO2 is set to spec the slight draft change that will occur through the seasons will be minimal. Newer high static pressure flame retention burners with no draft regulator are more stable than older burners with a draft regulator.
This discussion has been closed.