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HTP Fire Tube Boiler overheating

Redicliff Member Posts: 1
We have an HTP flash heater MC-100 that is overheating.
I've posted a 1.5 min video of the control panel as the unit cycles.
https://www.dropbox.com/s/cuakr4pa010f2xq/HTP Boiler Overheating.mov?dl=0

Not finding corresponding troubleshooting recommendations in the manual. Of course, if it's there, it probably reads "call a certified tech". But, we're sheltered in place a long ways from a tech.

Comments and recommendations appreciated


  • kcopp
    kcopp Member Posts: 4,392
    From the description you are not getting flow. Is something shut off, circulator broken or debris plugging the piping?
    EBEBRATT-Ed Member Posts: 15,317
    Or no or low water pressure in the system.
  • fenkel
    fenkel Member Posts: 162
    Check your pumps..water isnot moving thru HX..
  • GroundUp
    GroundUp Member Posts: 1,865
    Not enough flow, can hear it boiling in the HX. How's it piped?
  • hot_rod
    hot_rod Member Posts: 21,853
    they can be tricky to purge the boiler on fire tube design. i have had to hold the relief valve open if you do not have enough purge flow or pressure.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • fenkel
    fenkel Member Posts: 162
    Whats the boiler pressure? Should be a guage under the boiler?
    Upload more pictures, sometimes we can see issues..
  • Rich_49
    Rich_49 Member Posts: 2,766
    If this in fact an MC series boiler , it is not a firetube . MC Series was a water tube boiler
    You didn't get what you didn't pay for and it will never be what you thought it would .
    Langans Plumbing & Heating LLC
    Serving most of New Jersey, Eastern Pa .
    Consultation, Design & Installation anywhere
    Rich McGrath 732-581-3833
  • fenkel
    fenkel Member Posts: 162
    How old is boiler?
    Could HX be plugged?