Triac [BT 136] Based Fan Regulator issues

I had five step fan regulator which was not good(speed 5 is full and 1 to 4 is very slow , 4 is not even 1/4th of speed 5). I opened it and saw it has 3 caps and resistors . I went to buy a fan regulator which I saw at my friends house before which was like a volume controller . Shopkeeper told me this is dimmer for lamps. I bought one and replaced my old regulator. It worked and the next day irrespective of the knob it was at full speed , no variation in speed when I turned the knob( It worked for one day) . I took it out and opened it and saw Triac bt136, diac, and inductor (50uh), 2 caps , res, variable res etc. I checked the variable and found it to be ok. so I had a spare bt136 and replaced it. I checked it with a 60w bulb and it worked okay. I put it back and then checked - fan speed okay . This too only lasted for a day and again it is gone. (I consulted with my friend and he told me that he had few experience with this and finally stopped using it - he had the damaged regulators replaced by the shop keeper two or three times , but no use. - may be this is why the shop keeper told me to say lamp dimmer , may be he know it will not run for long time).

I don't know why this happening, may be becoz it is an inductive load. I have used this bt136 and PIC micro for Xmas lamp chasers and all, never had any issue before.

My question really is - any other triac to suggest. or point any web page with guaranteed working circuit diagram.