First post I've had a Hydron Module geothermal system in my house for two years, and have been getting the semiannual maintenance for free as part of my installation contract. From what I have observed, the maintenance involves cleaning the condensate drain & pan, changing the filter, and testing to make sure that the zones come on when called. Is there much more than this? Everything has worked fine from day one, I'm capable of doing what I saw done. My contractor wants to charge $1,000/yr for this, which seems quite high. Any thoughts?