Replacing HVAC/water heater system - what did YOU wish you knew before?

[PinballFamily]

Replace one recently? What tips can you offer? Wish you knew "X..." before you had your work done? We're trying to do our homework before getting quotes from several companies next week. There seem to be lots of product rebates/0% interest loans/state and fed tax credits, etc. available through the end of 2011, so this might FINALLY be the time to take the plunge.

Details:
1800 SF house in New England (100+ years old).
Forced hot air (gas) heater (24 years old) - thought is to replace with same, just much more efficient!
Gas water heater (12 years old) - 40 gallon tank - thinking of going to an "on-demand" system for this, but listening for pros and cons...
Want option (separate/additional quote) for AC - $ might make it worthwhile to add in now, not sure yet...

Thanks so much for any info you can offer!

 

[bettymae1121]

Well...we've got an HVAC guy here now (as I type this!) to give us a quote on a new gas furnace/AC package so I'll let you know in a few weeks!

 

[PinballFamily]

Thanks, BettyMae! We've got some guys coming out starting next week to check out our current set-up. Didn't even know (thanks!) that we might have to wait a few weeks for the actual quotes!!! Good luck with your project!

 

[Gr8t Fan]

We replaced our furnace and the inner workings of our central air about 4 years ago. I wish we'd known that it would be a PITA to have them vent the new system through the wall using PVC tubing and instead opted to have a ceramic liner installed in our current chimney. The ceramic liner option was more $$, but they made it sound like it wasn't necessary and the PVC tubing through the wall was just as good an option. IT ISN'T!!! The PVC tubes (2 of them -- one for air intake and one for exhaust) are covered with a screen to prevent critters from getting in, but those screens sometimes get covered with snow which prevents the system from working properly. Also the system produces a lot of water which drips from the PVC tube and freezes in winter. Definitely not fun. Definitely get the ceramic liner!