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.

Boiler rust

mike09 Member Posts: 8
I just looked at a Crown Boiler I installed 3 yrs ago, and it has rust on lower portion of heat exchanger jacket in on front side. This is a hot water system and I am not sure why. The reason I checked it today is because it wasn't working for customer, and error code was blocked vent damper switch, so I pressed the button on the safety switch and it lit. Does anyone have insight into the rust I am seeing? Could this be a leak between cast iron sections or a combustion / vent issue , which is atmospheric into chimney. Thanks


  • Tim McElwain
    Tim McElwain Member Posts: 4,628
    What is the typical return water temperature? Is the rust on the side of the boiler that has return water coming back to the boiler?

    Many times if you have low return water temperatures that can cause both thermal shock and also rusting on the burner area closest to the return water.

    Do you mean the blocked vent switch was off and you reset it? If so did you do a combustion test to determine if you have a combustion problem. That switch tripping is an indication that you have combustion products spilling out of the draft hood. Make sure you have adequate air for combustion.
  • kcopp
    kcopp Member Posts: 4,446
    What is the boiler model? Describe the system more please.