Here are a few things to consider.
1,Trane is usually higher as you are purchasing the tradename (What Grampa had)
2.Warranty issues: Once you purchase the Trane, you are pretty much forced to stay with a Trane dealer for service and repairs as Trane will not provide warranty parts to any contractor or homeowner who is not a certified Trane dealer.This allows them to charge whatever they choose for labor as you do not have the option to shop around for service.On the other hand, Rheem will provide warranty parts to any licensed contractor.
3.Both units are reliable when properly installed.There are some units on the market I would definitely avoid, but both of these are fine choices.
As for estimates I recommend at least three and have them provide details of what they will be doing.Cutting corners will make a difference in costs.Examples:
Will they resurface closet platform run new condensate drains,refrigerant tuning,install filter return griles,will a permit be pulled,what type of thermostat will they use(programmable,etc),be sure to compare apples with apples so to speak.
If you have further questions, please let me know.
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