After several years of service and savings (see my blog from 2009), our Intellicon had an issue in late 2011. The unit had a sensor fault (see below photos from early in the fault). Average savings of 24.3% for ET 3417.7 hours.
I contacted Intellidyne (manufacturer) with my serial number, installation date, name of installer and reported error.
Michelle Arroyo answered my call and sent me out a new sensor at no charge.
The part arrived (with instructions) and I installed it over lunch. It was so easy!
This kind of service is remarkable. Intellidyne makes a great product and stands behind it.
If you have an oil boiler, look into adding one of their retrofit units.