I currently have a Lennox 5 ton heat pump and furnace using a honeywell mini 3 zone system. Every piece of hardware inside my Lennox heat pump as been replace and it is only 6 years old. Last summer, the compressor went out under the 5 year warranty and Lennox (after many long battles) sent a new one to replace the old one. I have had that compressor exactly 10 months - and it is now out. Seized up apparently. I am tired of Lennox - and so it my pocketbook. I haven't had any problems with the furnace though or the 3 zone system. My question is this:

I have had 3 HVAC companies out and they all have different concepts of "fixes" - no one will replace just the compressor, since no one can figure out why it keeps failing and since it has failed you can't "test" it now to figure it out, so I can't even get a quote on that - but I hate my heat pump, so I don't really care about that.

Here is what I want to know:

I have been told even though the system is only 6 years old - I CANNOT put a different type of heat pump in and leave the Lennox furnace so I have gotten bids for a new Lennox heat pump (which I don't want) or an entire new system to replace just the broken compressor. Then I have a bid from a different company that says I can replace just the heat pump with a Heil 15 SEER R140A heat pump and keep my existing Lennox furnace.

Obviously, bids are ranging all over the place and I know I want a more reliable heat pump - no more Lennox. But - I also don't want to spend $$ for an entire new system if I don't have to - I have checked all over the internet and can't find anything that talks about mixing brands of heat pump/furnace - so I am asking if that is a possibility or a horrible idea?

Thanks for any help you might be able to through my way.