First it was propylene glycol becoming aggressive and venting (and later leaking) from a seal that it had damaged. Then it what the manifold venting and leaking propylene glycol. So we gave up, flushed the loops and refilled them with water for the summer. Then the condensation catch pan kept having an inch of standing water in it. As spring turned into summer and the air conditioning began to kick on, we could smell freon (410A) coming from the air registers, permeating the furnace room, and very thick smelling in the finished basement. Called the contractor out with his sniffer gadget and, sure enough, he found a leak on the coil. Contractor ordered and installed the new coil and..... we still have a freon smell coming from the air registers, permeating the furnace room, and very thick smelling in the basement. But on follow-up trips, the contractor can't get his sniffer gadget to alarm. So after the last unsuccessful service call, I noted the make / model of the sniffer that he uses and as soon as he left, I went on to amazon and bought my own. It alerts intermittently, even though I can smell and feel freon in the air.... it smells like chemicals, makes my skin burn, as well as making me dizzy, lightheaded, nauseous, tight throat, and short of breath. Even the pets vomit on days when the smell is really obnoxious. I agreed with him that there should either be a leak, or not. But there's what "should be" and there's "what is happening".... and in my system, it seems to be intermittent. The kicker is, I just got diagnosed with cancer last week. Doctors will be scheduling several surgeries in the coming weeks, and possibly chemo / radiation if the surgeries are unsuccessful, and if I choose to go that route. Being in this house with these chemicals coming from the geothermal system makes me sick and I've been feeling terrible since November 2015 which is when the problems began with the glycol. I cannot come home to this house after cancer treatments and expect to heal. I took a video with my phone of me getting the sniffer to alert at an upstairs air register. I'm wondering if the freon smell is so thick in the basement that the sniffer self-calibrates to an already high level of freon, thus making it difficult to detect inside the trunk of the furnace. I tried to attach the video here but, I don't seem to be able to. At the least, I'll show it to the contractor. FYI ~ this sniffer is calibrated only for refrigerants, nothing else. Any suggestions you guys might have on how to resolve the current freon problem would be appreciated. If I can't get it fixed within the next couple of weeks, I will be looking to rent a house or an apartment that does NOT have a geothermal heating system. I just don't have the energy for these kinds of problems anymore. I want to be able to focus on my health without constantly being distracted by geothermal system problems.