We have the very same JL freezer. Started doing the same recently. Temp rising then falling. Called JL. Not interested as it's 4 & a half yrs old. No extended warranty with them. Just gave us number to phone. Called customer service and they just said same. £80+ call out. JL said if it was a fault inherent to that model it would have been recalled. Waiting for their engineer but he can't come for over 2 weeks. Not sure I want to pay them £80+ to tell me it's not working.