Find the right heating and cooling contractors

Here in the Bay Area, we worry about earthquakes. We occasionally cough on smoke from distant fires. But — Mark Twain’s opinion about San Francisco’s summers aside — local weather ranks as a positive. That doesn’t mean we can get by without furnaces or, in some parts of the area, air conditioners, which could become more important if climate change predictions are accurate. To ensure that your HVAC systems work when needed, it’s important that they are properly sized, installed and maintained. You also need someone you trust for maintenance or if problems occur. In short, what you need is a competent, responsive heating and air-conditioning service.

Bay Area Consumers’ Checkbook evaluated 58 Bay Area heating and air-conditioning services. Checkbook collected ratings from customers who used the services, and Checkbook researchers anonymously gathered prices on carefully specified jobs.

Consumer ratings varied substantially — some firms were rated “superior” for “overall quality” by 90 percent or more of their surveyed customers, while many received “superior” ratings from 60 percent or fewer of their surveyed customers.

Prices varied even more dramatically. For example:

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•To replace the blower motor and capacitor for a Trane XR90 single-stage gas furnace, the lowest price was $330. The highest? $950.

•Prices to supply and install a Honeywell VisionPRO TH8110R1008/U programmable thermostat ranged from $237 to $687.

More Information Editor’s note: The Chronicle is partnering with Bay Area Consumers’ Checkbook magazine and Checkbook.org, a nonprofit consumer group with a mission to help consumers get the best service and lowest prices. Checkbook is supported by consumers and takes no money from the service providers it evaluates. You can see Checkbook’s evaluation of heating/cooling firms, including price comparisons and advice on choosing firms and systems, until Nov. 7 at www.checkbook.org/chronicle/heat.

In instance after instance, Checkbook found similar differences. This is a field where it’s definitely worth your time to collect repair prices or installation estimates. If you know what you need — a new blower motor for example — you can obtain prices over the phone by supplying details about your equipment. More often, you’ll need to someone come out to diagnose the problem. Since most companies charge hefty minimum fees just to show up, you’ll probably have to pay something to find out the price of the repairs.

Once a company has diagnosed the problem, get a written estimate of how much it will cost to fix. If the repair estimate is no more than a few hundred dollars, you may as well have the company go ahead with it immediately — because you may have to pay another company a minimum to come out, probably eating up any possible price difference. If the estimate exceeds $500 or so, consider getting additional quotes from other companies.

If you need new equipment, make sure to get several companies to prepare written proposals — Checkbook found that doing so can literally save thousands.

When weighing proposals, be skeptical about claims of cost savings from a more energy-efficient system. There may be substantial savings — and there are compelling public-interest reasons to install efficient equipment — but some companies exaggerate the amount of savings to sell new, or more expensive, equipment (more efficient equipment costs more). Get several companies to make proposals, ask for documentation of how much the new equipment will cut your energy bills, and ask questions. You can calculate your own estimates by using the Department of Energy’s Home Energy Saver tool at www.hes.lbl.gov.

For an illustrative home, Checkbook estimated how energy costs are affected by purchase of new equipment with varying energy efficiency ratings and found:

•For furnaces, the resulting energy savings fairly quickly make up the increased cost. In most parts of the Bay Area, it makes sense to pay extra for a more efficient furnace, compared with a minimally efficient model, because the savings on your utility bill will be worth it.

•In this area it usually doesn’t make sense to pay more for a highly energy-efficient air conditioner rather than a basic unit.

•The high cost of most heat pumps and the relatively high electricity rates here in California make heat pumps less financially desirable than gas furnaces.

•Investing thousands of extra dollars in ultra-efficient equipment makes no sense if your home is drafty or poorly insulated, or your thermostat is pegged on Tahiti during the winter.

Before upgrading your equipment to lower bills, make sure your attic is well insulated and seal up easy-to-fix leaks (at Checkbook.org, you’ll find advice on these topics). The best way to cut home energy costs is the most obvious one: Dial down your thermostat, and get and use a programmable thermostat.

Heating and air-conditioning services often hard-sell professional maintenance visits, and many will offer a maintenance contract. Such frequent professional service may not be needed as long as you are diligent about the most important maintenance task: replacing air filters whenever they get dirty.

Finally, whether you need repairs or a new unit, pay with a credit card. If you are dissatisfied with the work, you can dispute the charge with your credit card company.