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.

Honeywell Thermostat CT30A

Why does the small thread inside of the thermostat keep breaking and shutting the boiler off. I have replaced the thermostat 5 times now.


  • STEVEusaPA
    STEVEusaPA Member Posts: 6,393
    Whatchyatalkingabout Willis?
    Post a pic
  • ratio
    ratio Member Posts: 3,555
    Is it broken, or melted/burned looking? Those mechanical heating stats are pretty robust, physical damage is my first guess for "broken". Melted or burned, however, means something else. If that's the case, the thermostat is probably switching too much current. How old is the boiler?

    Do post a pic of the damage of the stat. Without that, we're just guessing. you can attach a photo via the icon above, or by just dragging it onto the msg.