If it's still putting out the right heat, it's still working, it's not like UVB.Sounds very cosy.
Do CHEs have a life span? Mine is over 2 years old now and still giving off good heat, I haven't thought that it may need to be changed. Will do though if it's needed.
Lola has the warmest room in the house - I've bought him a new oil free rad so I can turn my heating off and save some pennies.
If it's hot, it's fine.