I have a climatemaster 27 that was installed in June 2008. Last week I discovered that the coil has many holes in it and has failed. At the same time the technician informed me of the need to replace my coil, he told me that the original installer failed to install a thermostat which enabled me to utilize the second stage of the climatemaster 27. I normally maintain my heat on the cool side and my AC on the warm side except when I have company. I have always had a problem achieving the desired temp in a timely manner. Could the coil failure be due to the fact the system was not able to ever utilize the second stage? Thank you all for your assistance.

umm... if the coil has many holes in it, that would not let heat pump meet your needs. If thermostat would not let heat pump go into second stage, it would not meet your needs.....
what else can we say with info provided.
j

I don't see how an improper thermostat could cause a coil to leak

I cannot see that either (how a single stage thermostat or running in first stage only can damage the coil). The pumps are supposed to run in first stage 85-90% of all time. Open or close system? What is your thermostat model number? The coil should be under warranty by CM, you might be stuck with the costs to get a three stage thermostat if your installer is out of business. Did you try to contact him again?