(This post is part of the Genuinely Approachable Sudoku (GAS) series.)
As in this Thermo-Sudoku (Missing Bulbs) puzzle, numbers on Thermos will strictly increase but it’s up to you to deduce which end has the missing bulb.

PDF

or solve online (using SudokuPad)

Author/Opus: This is the 178th puzzle from Bill Murphy, part of the Genuinely Approachable Sudoku (GAS) team.

Rules: Standard Thermo-Sudoku rules (insert a number from 1 to 9 into each cell so that no number repeats in any row, column, or bold region). Some thermometer shapes are in the grid, but the bulbs are missing. For each thermometer the bulb should be positioned at one of the open ends, and then the numbers will be strictly increasing from that round bulb to the remaining flat end.

GAS Time Standards (highlight to view): Two party hats (🎩🥳): 6:30; One party hat (🥳): 12:00. All other solvers earn an 🦕: Invisible Isisaurus.

Thomas Hits the GAS (highlight to view): 2:16, with SudokuPad replay file shared as a download for now (requires loading via settings menu with improvements expected before people should use this regularly).

Solution: PDF

Note: Follow this link for more Thermo-Sudoku puzzles. If you are new to this puzzle type, here are our easiest Thermo-Sudoku to get started on. More Thermo-Sudoku puzzles can be found in these books in our e-store. Also, visit this page to purchase all of the puzzles from the 16th World Sudoku Championship including some Thermo-Sudoku.

Note 2: Comments on the blog are great! For a more interactive discussion, please also consider using our Daily GAS discussion post on the GMPuzzles Discord. Not a member of the Discord? Click this link for basic access.