Life Span of Arduino/ DIY Thermometer

Projects General Guidance
1

I am looking to use an Arduino to read temperature data and control a servo attached to a thermometer dial. I am trying to get the whole set-up to last as long as possible without any maintenance. I have been looking at the documentation, and I'm not quite clear what the life span of an Arduino wold be if constantly run.

I was also wondering if this forum could help with the general ideas of the project:

Are there any easer ways to control a thermometer dial?
Are there any programming tips to save energy?

2

I'm not sure what you mean by a thermometer dial?

However, in general you can expect the mechanical components to fail long before the electronic ones.

3

Sure, use Honeywell 7 day a week/multi-time a day programmable thermostat.
~$100 at Home Depot.
Battery powered, LCD display, relay to open/close heating wires. Possibly good for rebate from your energy supplier also.
I have had 2 of them (the same 2) running my 2-zone forced hot water system since 1990.

http://www.homedepot.com/h_d1/N-5yc1vZasjh/h_d2/Navigation?langId=-1&storeId=10051&catalogId=10053