Thermo Sudoku Help

Thermo or Thermometer is a variant of Sudoku which overlays thermometers on the grid. Thermometer consists of bulb cell and thermo line cells. Value on thermometer must increase from circle bulb end to the other end. Values on thermometer cannot repeat.

Thermo Sudoku Solving Strategies

If thermometer is 9 cells long it must contain all digits from 1 to 9.

If it's 8 cells long each cell has 2 candidates.

It if's 7 cells long, each cell has 3 candidates.

By limiting candidates in some cells we can limit candidates on all thermo cells.

If we remove 4 candidate from box 1 and 7 from box 2 we have the following candidates left:

Those candidates are still not valid, if we try to put 6 in yellow cell, we will have to put 7 on thermo in box 2, and 7 is not available. That's why yellow cell must be 5, and after 5 we have 6, 8 and 9 because 7 is not available.

Candidates lower than 5 must be 1, 2 and 3, since 4 is not available.

Two cell Thermo constraint can be a replacement for Greater Than.

Thermometers can share a bulb (or any other cell). Following grids are valid: