Hi. Im having loads of trouble keeping my vivs at the correct temps. I used to use heat mats with no probs, but due to my royals getting bigger I have switched onto ceramic bulbs , which have given me nothing but trouble

I hsve checked the witing an that all fine, they are on stat which re working fine. What happens is they work when i initially put them in but then stop working after 2-3 weeks: I have tried chaning fuses, taking them out and putting them back in, I'v checked the wiring and made sure there is nothing shorting them. Also they are surrounded by guards so they cannot be 'got at' by the snake.
I am at a loss what to try next, and it is costing me a fortune

any suggestions welcome
__________________

1.1.0 Normal Royal Pythons (Doug & Ruby)
1.0.0 Pastel Royal Python (Bruno)
0.1.0 Spider Royal Python (Cleo)
0.1.0 Dwarf Crawl Cay Boa (Lily)
1.0.0 Spur-Thigh Tortoise (Mr. T)
2.0.0 Dogs: English Bull Terrier (Aston) & Jack Russell X(Sammy)
0.0.1 Horsefield Tortoise (Lenny - in pic) for sale, PM me for details