Easy Peasy Sudoku Advent (15) - Thermometers - Removed Bulbs
(Published on 15. December 2025, 06:00 by Richard)
This sudoku advent calendar contains 24 variants that were included in my Sudoku Variants Series (SVS) but turned out to be too hard to be solved by a wide range of puzzlers. I aim for difficulties of 1-2 stars and have written some general and/or specific hints as well. I hope some players will try the original SVS puzzle #318 after solving the advent version.
Thermometers - Removed Bulbs
General hint for this type:
It is helpful to start with the long thermometers to figure out where the bulb can be.
The thermometer in boxes 1,2 and 5 has both ends in box 5. Six of the end digits are in that box, meaning one of those digits can be at most four. That is a good indicator for where the bulb can be.
Apply classic sudoku rules.
The digits in a thermometer are, from the bulb to the/each end, all different and placed in increasing order. The bulbs are removed and placing them is part of the puzzle. Bulbs can be placed on every place on a grey line; in case the bulb is on an end, the line forms one thermometer, in other cases exactly two.
Solution code: Row 8
Comments
on 7. January 2026, 12:13 by Eisbär
At last... what a nightmare this was :-P
on 27. December 2025, 23:57 by Tws
Not as easy as the other ones! The start is tricky! Thank you for this fine creation!
on 20. December 2025, 23:00 by SennyK
Wow, this one was really tough! But simultaneously very satisfying when the path was found :-) Thank you!
on 17. December 2025, 23:46 by walid_tun
I found this one particularly hard.
on 15. December 2025, 21:26 by fishwithapipe
I found this one pretty straight forward, though took me a few minutes to spot the final step.
on 15. December 2025, 18:10 by hamosphere
Not easy peasy!! Cool concept though, I would need more practice to understand the logic flow here.
on 15. December 2025, 15:27 by wuc
Tricky but fun break in logic. Cool puuzle thx.
on 15. December 2025, 15:27 by henrypijames
The first one in this series that is definitely not easy-peasy for me.
on 15. December 2025, 14:25 by Franjo
Quite tricky for „easy peasy“. I hesitate trying to solve the original one. Maybe too hard for me… But thank you very much for creating and sharing this puzzle.
on 15. December 2025, 11:17 by marcmees
Not so easy peasy break in, but very nice flow after that as usual. Thanks
on 15. December 2025, 08:09 by Piatato
Hardest one so far, but then again I have yet to not break the original.
