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Ultra 155 not firing when calling for heat

I have an Ultra 155 that apparently stopped working over night. Fortunately, I have an outdoor wood boiler running so I still have heat at least somewhat.
The display shows 0 and water temp. If I hit reset, the system runs through its startup and I can hear the boiler circulator pump run (and verified with voltage check) and then shut off. According to the manual, all fuses were checked. Manual says to jump terminal 5 and 6. When i do that, fuse F1 blows. The manual doesn't say what to do in that situation. Any ideas?
Further actions require replacing the control module which of course is discontinued (part number 383-500-190).


  • ktm250rider140
    ktm250rider140 Member Posts: 3
    Correction, jumping low voltage 5 and 6 has no effect on the operation
  • Ironman
    Ironman Member Posts: 7,223
    Which terminal block are you jumping 5&6 on, the red or the gray?
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
  • ktm250rider140
    ktm250rider140 Member Posts: 3
    5 and 6 on the low voltage terminal strip. However, the importance of following the troubleshooting procedure. Step 2, which i ignored proved that the space heating was turned off. Not sure how that happened or got reset during all the power cycle. But its back to working.