Is the labor warranty from the dealer or a manufacturer. Third party labor or extended warranties are problematic. If it's a dealer only warranty, it's only as good as the dealer is willing to stand behind it. Get the warranty in writing and specifically understand all exclusions. That's the best advice I can offer. The big ticket items as far as replacement goes of course would be the compressor in the outdoor condenser and var speed blower motor inside air handler. Most of the electronics can be pricey to replace but the labor generally is not a big factor. Leaking coils can be an issue. And not meaning to scare you but Lennox is behind the curve in this area as far as best material. The difference between the labor warranty may be more of a selling tool. I personally would lean toward the dealer you have the most confidence in as far as a good install.

IMO