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Smith GB100W boiler problem/question

astoria2013 Member Posts: 16
I have a new customer that has 3 of these boilers that has to at least 2 times a year change rollout Switches. His chimney is 10 inches which I suspected was the Problem, but upon further inspection I found this. See pic. Has anyone ever seen anything like this before? All 3 boilers have it. Just a plate covering 3/4 of flue right before vent damper. Boilers are 50,000 btu. Nothing in manuals I have found have any mention of this plate which seems to be part of boiler. Thanks in advance.


  • Ironman
    Ironman Member Posts: 6,600
    If it's factory installed, I wouldn't worry about it.

    You obviously have a chimney issue. 10" is way too large for a 50k btu appliance or even for three of them if they're common vented. What's the chimney height? Is it a masonary chimney on an outside wall?
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
    EBEBRATT-Ed Member Posts: 10,371
    If the chimney is oversized the chimney takes time to heat and produce draft, it may even backdraft a bit when starting with a cold chimney
    HVACNUT Member Posts: 4,214
    That certainly is a fusible link rollout switch when typically there is a spill switch in that location.

    Check the key on the wiring diagram to see if that's the correct part.