My Iguana refuses to bask below the UVB light?

I just got my iguana 2 weeks ago. When i got him i got him with cages, UVB and UVA/Heat lamp. However, as soon as i place the UVB into e27 socket, it blew up and i had to wait for 2 weeks to get another one. Just 4 days ago, i got the UVB but i accidentally broke the UVA/Heat lamp so i had to wait another 1 week to get another heat lamp. The problem is, i bought the UVB and set it right, inches away from the iguana (approx 15 cm away) but he refuses to bask below it. What should i do?