Going to get some quotes on new furnace/ac
Back around 1993 or so my original furnaces crapped out and the original HVAC contractor for the building contractor sold me on a pair of 92% high-efficiency TempStars with supposedly stainless lifetime heat exchangers. They also set up these homes weird, two zone/two systems with a single return trunk feeding into a "Y" but no automatic damper. So now I have one heat exchanger with a 1/8" long stress "crack" emanating from under a screw head. The new service people said the crack warrants a red tag but at this point its a little line in the metal, nothing open. My original guy retired 10 years ago and is probably somewheres in Florida LOL.
One system is 2.5 tons and the other is 2 tons IIRC. One AC has a brand-new compressor installed 3 months ago. The AC works beautifully now. And while they are HE units they are the old refrigerant style. So they are recommending replacing the two furnace/two condensor-compressor setup with a single 4 ton 92% efficiency unit, and adding an electronic damper to deal with the returns. And a single, modern refrigerant compressor outside.
Initial price for the new 92% HE furnace/ac was $12.7K and $2.5K for the damper system with two new electronic thermostats and a hard-wired CO2 detector in the furnace area. System would have 1-year free service, 10-year warranty. They would leave my Aprilaire 2210 filter and my existing humidifier and only need a minimal amount of new duct work to work with the existing trunks. No brand is cited, and they said its not the brand but the install & maintenance.
The alternative is to replace the heat exchanger and I've written to TempStar's parent company but haven't heard back yet. My new service company estimates $600 for the part and $2200 to install. They could theoretically add the damper system in to make it work better, but that does add probably $2700. Right now when ground floor calls for heat its freely drawing return air (and some heat) from second floor returns. The damper supposedly will do a better job than the current system but I don't really know how if there's a common trunk. Maybe somebody could explain that... maybe its a dual-damper setup but there's probably no way _not_ draw air from the entire house with a common return trunk... right?
Anyway, are the prices high or average sounding? I live in Western Mass, and of course the furnaces are gas-fired. This is a very unexpected event and the crack showed up in the Fall routine service.
Thanks in advance for any.all advice.