Will 31vdc burn up a 24vdc coil?

 

Wihud... Welcome to the forum!
You asked an interesting question. I happen to have the 3rd edition of the Struthers-Dunn Handbook, "Relay Engineering" !

It "states" that a variation of plus/minus 7.5% variation in wire resistance is considered acceptable.

Remember, heat loss is related to the square of the voltage applied ! That is, Watts = V*V/R. In your case the heat gain is substantial, and it will "burn up" a 24Vdc coil. Do the numbers ! I suggest you measure the coil resistance, R. The voltage increase is 29%.

Regards, Phil Corso