Our 3 year-old geothermal 1-ton attic system occasionally shuts off. Each time it does, we're given a different reason for the shutdown. The most recent shutdown was caused, we were told, by low refrigerant levels – they said we needed 2 pounds added. Incidentally, we noticed our most recent maintenance agreement was changed from the prior two agreements to omit, you guessed it, 2 pounds of refrigerant added if needed. So we had to pay for the refrigerant.
Now I'm wondering what comes next. If we need refrigerant there must be a leak, right? Or does it somehow evaporate in the system over time? Our geothermal system is still under warranty. I want to approach the business that installed the system but thought I could use more information beforehand. Any thoughts on this? Is it common? Is this toxic?
Indeed, this is very suspicious.
One of the common fears and very real pitfalls with geothermal systems is they require impeccable installation, and are prone to leaking. Once that leak springs, it can be very expensive to repair because accessing those coils can be near-impossible.
I also think the warranties offered on these systems are somewhat misleading. Let's say a system is warrantied for fifteen years. Often, that warranty will cover the cost of the coils, but not the cost of labor and installation.
You have enough history to document what's happened. Put that info into a detailed, direct letter. Then take that letter to both the manufacturer and installer and ask them to address it. You want to address it to both of them, jointly, because both of them are potentially liable. Your system should not be leaking refrigerant at these levels.