R410A, the pink stuff ^^ with just under 2 years old isn't the warranty valid? I'd check with the builder and his sub-contractor. You're talking less then two cooling seasons (maybe ten months total) of use! 227 posts, read 285,883 times Yes, the warranty should still be valid. We registered it online through the builder, which according to them the warranty is 10 years. Originally Posted by DubyaM Yes, it is on the outside condenser unit. Originally Posted by wit-nit We did and they will be sending out a tech on Thursday morning. Luckily it is only one of our units, plus this week it isn't supposed to be too hot. Not sure what it was, since we had it turned off until the tech came over. , and they confirmed that this would actually cause this: Carrier air conditioner not cooling and making rattling noises From what I read elsewhere, a lack of refrigerant will actually cause the refrigerant line to freeze up. Since we likely lost most of our R410A refrigerant due to the leak, this is likely the reason why the line is freezing.