I just recently made a little circuit composed of NEUT, compressed DEUT, TSNS and PBCN.
it is very simple:

1. TSNS detects high temperature, then passes SPRK to PSCN.
2. PSCN passes to PBCN (NEUT).
3. NEUT go through compressed DEUT, resulting in a boom!

And everything is fine.
Save:

Tested on Destroyable City 5: Destroys two buildings and a plane, also makes a huge crater crushing the metro.
Hope you'll like it!

PS Do not heat it up, as TSNS also will, just set it on FIRE or what.
PPS Also made an auto-explode version, click the link in the save.