Posted: 08/08/2013 at 07:02
Probably a combination of things, HG. Pollination isn't happening. Though peppers are self-pollinating, they can need a helping hand. Outside, insects can trigger pollination by fossicking in the flowers. In a greenhouse, with fewer insects, you can help by giving the flowers a gentle flick with your fingers.
Extremes of weather can also impact on the pollination process.
You could also be overwatering. Unless the pots are small and it's exceedingly warm, they shouldn't need watering every single day. You can afford to let the mix dry out.
An excess of fertiliser can also impact on fruit production. How often are you feeding?