It sounds as if the flowers are not being pollinated. The plants need to be kept somewhere that insects can have ready access to or you will need to pollinate them yourself with a paint brush.

Yes you need to hand pollinate them if they dont get any wind or insects

I would have thought it was a bit late for peppers, mine finished weeks ago.

i agree tulsalady, i keep mine in a cold greenhouse and spray regularly overhead or give them a little shake but generally i let them get on with it I have the windows open and have had a very good crop this year-- i do find that they like it warm and i certainly could not grow them outside

Agree with all the above. If they are in a greenhouse, then you should really have ventilated it during the summer which would have let the polinaters in and the heat out. Other than that, you need to keep them well watered (bottom watering is fine I would have thought, so long as the whole root ball gets watered) and also you would need to feed regularly to set and keep the fruit. I just harvested all mine the other day and chucked the plants onto the compo.