Selecting a good contractor - kind of long.

[STravis]

I'm looking to replace my 12 yr old furnace (came with the house when I bought it a few years ago) with some decent and am looking for a good contractor to do the job. Although no one here can tell me which contractors are good in my area, perhaps you can help me out. So far I have 3 bids on the job and am not looking for too many more bids. House is a 2 story colonial and a total of about 1600sq.ft. without the basement. I'm looking to get the furnace replaced with a 92% AFUE (or greater) two stage unit.

Anyway, here's the story.

Company A: A couple of weeks ago I had the A/C serviced at which point I had the service tech look at pricing out a new furnace as well. He noted that the present furnace is way oversized for the house's duct work (125000 BTU). He recommended an 80K BTU unit along with all the associated replacements (humidifier), etc. While he was there, he also reconfigured the existing furnace to slow down the blower and allow it to run the air slower over the A-coil so as to make it more effective. He gave me a quote on a Trane, but didn't really detail model numbers, etc. His total time was probably around 1 hour including the time it took to service the A/C.

Company B: This guy came in purely to give me a quote. He looked at the furnace (didn't really take any measurements) and recommended a 100K BTU furnace for the house, indicating that two stage units can be sized lower than the existing furnaces. This guy had all the pamphlets for the furnace components and went over them in detail. He gave me two proposals listing all the part #'s for everything he was putting in - one with a new AC unit and one without - knowing that the AC unit outside is only 5 years old. Total time spent at my house was around

80 minutes.

Company C: The guy also came in to give me a quote: He took measurements from the furnace (measured all the duct work around the furnace) and indicated what the work would be - while we were around the furnace; He also took a look at the AC condenser before he gave me the quote. Anyway, he gave me the quote detailing the work and all the components he was going to use (with part #'s). Total time spent at my house was around

30 minutes.

Company A/B are selling Trane units while Company C is selling Lennox - I don't think that's a make/break situation are both are very good units and a hell of a step up from what I have now.

Lastly, Company A/C are within 10% of each other in cost while Company B is about 80% more expensive than Company C. Also Company A has been around for 35years while Company C has been around for at least 15 years and they do offer 2years labor. Not sure how long Company B has been around as this wasn't brought up by the sales guy.

Sorry for being long winded on this but I would like to get honest opinions on this.

Thank you.

[Travis Jordan]

First you need insure that all bids include a "Manual J" heat loss calculation prior to final system size selection and installation. That is the only way to know for sure what size furnace you need. You will also find out what your A/C load is which may be useful regardless of whether you are replacing your A/C system or not.

Once you've down selected to two or three contractors be sure to check their complaint record with your state and local licensing boards and of course the BBB. I've also had good success in calling the local building department, asking for a mechanical inspector, and then asking them if they would use any of your selected contractors to do work in their own home. Most times the inspector will steer you away from using a troublesome company.

[Travis Jordan]

You need to be sure to compare apples-to-apples. Trane makes various grades of equipment (all the way from the low-end "builder grade" hardware up to super-efficient premium systems). If a contractor gives you a quote without model numbers it doesn't mean anything.

[Walter R.]

When I was shopping for a new furnace and A/c, I obtained 8 bids. I made sure I had all of them quote on very similar equipment. They ranged from $

8,000 to 16,000. (2 units). First of all I eliminated all contractors that where not enthusiastic about getting a building permit, leaving 4 contractors. Then I eliminated out-of-range bids. Then I checked them out with the Contractors License Board for license, insurance and bonds. Was very satisfied with the contractor that bid $ 8,000.

[STravis]

So far none of the contractors have done a Manual J calculation. Two out of the three have been in business long enough that I believe they could eyeball it, but that's just a theory. Also, wouldn't the system be sized according to the duct work presently in the house? Would a Manual J size a furnace that could lead to duct changes?

The ones that have been around for a while have no marks against them. The highest priced of the three is apparently two new.

[Travis Jordan]

Usually downsizing isn't a problem for the duct work, but upsizing can be. OTOH this assumes the ducts were designed properly in the first place - which in my experience isn't generally true.

If you want to be comfortable and have an efficient system then it needs to be designed to satisfy the heat loss (gain) of the home.

[trader4]

You also have another important reference point for sizing the new system. And that is how the current system is performing. Does it heat/cool the house off quickly? If it does, then I'd be inclined to go with a smaller system. If it does not, then I wouldn't, at least not without understanding how the smaller system is gonna make it work.