Do not allow a "sealant" to be put in the system. My opinion is that it does not belong in there. It will only gum up the system. Find out where the leak is located and see if it can be repaired. If not it was mentioned earlier that manuf. usually offer a 10yr. parts warranty. Call a manuf. rep...
Can you send me a copy of your invoice? Maybe I can lead you in a different way. It might not be as bad as you think. I'm willing to take a look at it for you
Gary
You can't keep throwing money away by dumping more gas in it. Bottom line, the leak or leaks have to be repaired. If it is beyond repair normally the manuf. will replace the damaged part under warranty. What area of town are you in?
I don't understand, he stated he checked the thermostat in heating mode and the cooling circuit was still energized? Sounds to me that there is still a problem in the board or the stat. $250 labor to replace a warranty part is just not right. Standard hourly labor rates should apply. 30 minutes...