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Replacing Your Furnace? Here's What You Need to Know


How do you know its time to replace your furnace and what do you need to know before you do? These are questions that eventually occur to most homeowners. Itandrsquo;s not an everyday eventandmdash;gas-fired furnaces typically last 15 to 20 years. Still, if you move into an existing home or keep a new house long enough, youandrsquo;ll probably be faced with this decision.


If the unit is approaching the end of its expected service life, you should start considering options to replace your furnace. Making the switch may be the right call even before then, however, in certain cases:

  • If the furnace requires expensive repairs such as replacing a cracked heat exchanger, itandrsquo;s probably not a viable investment if the unit is older than 10 years. Upgrading now may make better financial sense.
  • If furnace efficiency is so low that monthly operating costs are excessive, you might want to cut losses by installing a new furnace now. Lower costs begin on day one of operation.
  • If an aging unit simply no longer generates consistent heat to keep the house comfortable, it may not be a repairable issue. A new furnace is the best option.


Any new furnace purchase should be preceded by a professional heating load calculation to determine the required BTU output. This allows the contractor to select a furnace with the appropriate capacity to heat efficiently and effectively. Over-sized and under-sized units deliver poor heating performance and higher costs.

Have the furnace installed by certified technicians. This is a job for HVAC professionals, not a general carpenter or local handyman. Sub-standard installation practices can “build inandrdquo; low energy efficiency and poor heating performance that will be an ongoing factor for as long as the furnace is installed in the house.

Donandrsquo;t ignore other issues that affect furnace efficiency. Have your ductwork tested for leakage and sealed if necessary. Also verify that insulation levels, particularly in the attic, meet current Department of Energy recommendations.

For more advice to replace your furnace, contact the pros at Valley Heating, Cooling, Electrical.

Our goal is to help educate our customers in the South Bay Peninsula and Santa Cruz areas of California about energy and home comfort issues (specific to HVAC systems).

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