Triac motor controller
The BT208S is a smallish SMT triac-  you will be dissipating 5-6W (assuming European mains) with a 1000VA motor. That's a lot of power.. Probably your heat sink is woefully inadequate for the power dissipation and the triac is overheating.

If just mounted on FR4 board the Rth-ja is 75K/W so 5W would heat it to about 400C -- so maybe your heatsink is better than that, but nowhere good enough. 

Edit: For that amount of power, to keep the junction temperature sensible, you either need a BIG heatsink coupled thermally to the MT2 of the triac (might require an aluminum board) or a fairly large heatsink with a lot of air flowing over it. 

If you just want to turn the motor on and off, forget about the triac and use a power relay.