1 gang dimmer - low bulb output

[ianmcdlt]

I changed a light switch to dimmer. Only red and black cable. Straight swap. Black in L1, red to ~.

When I turn the power on the dimmer intermittently works and when it does only generates a low glow to the bulb when dimmer is turned to maximum. (single bulb).

Could anyone shed light on my problem?

[plugwash]

is it an ordinary filament bulb running directly off the mains? is it between the minimum and maxium power ratings of the dimmer?

if the answer to both those questions is yes then it is almost certainly a faulty dimmer.

[ianmcdlt]

Thanks Plugwash for reply,

Ordinary filament bulb = 60W 240 volt.

Dimmer = 1 Gang 2 way 250 Watt Dimmer