philba,
You don't need to put a too low resistor value, those 180 ohm is too low. Only need a resistor that provides enoght current to clamp the triac, with only a few uAmps its enoght. So, I don't know what is the value of "v hot", but if suppose VHot=313 V (PEAK), and you will put 500 uA to gate, the R could be: 313V/500uA= 616 Kohm. Even, you can choice, for example: 220K or 470K. Then power of resistor: V^2/R = 313 * 313 / 220k= 0.44 Wat. And 313*313/470k = 0.20 Wat.
Remember that 0.25 W resistor max tension is 150V, so you can put 4 resistors of 100K 0.25W in series.
Hope it helps