Dear Angie: How often should a central air- conditioning unit be serviced if there is no problem? My unit is 10 years old. — L.O., Hopewell Junction, N.Y.
Answer: Even if you don't suspect any problems with your air-conditioning unit, highly rated heating and cooling experts on Angie's List say it's a good idea to have it inspected and cleaned once a year — ideally in the spring — to ensure it operates at peak efficiency and is ready to cool your house during the months you need it most.
As your system runs, it accumulates dust and dirt in key areas, such as like the condensing coils and air filters, that affect its efficiency. Left unchecked, your system can lose 5 percent of its operating efficiency each year through a buildup of dust and dirt, meaning it can't cool your house as capably as it could if it were clean.
Many heating and cooling companies offer low-priced preventative maintenance inspections — costing on average $60 to $100 — in which they'll clean your HVAC unit and replace your air filter. Some companies even offer discounts if you sign up for an annual plan and will provide preferred scheduling to those customers, should an issue arise during the busy season.
These inspections are worth it and can pay for themselves through improved efficiency and a longer-lasting unit. A yearly maintenance check by a licensed HVAC expert can help reduce your monthly energy bill by up to 15 percent and help prevent earlier-than-normal breakdowns. Replacing your air conditioner, by contrast, will cost several thousand dollars. Even small repairs can run several hundred dollars.
A qualified technician often cam find and address small problems through a regular inspection that, left unnoticed, could grow into larger, more expensive issues.
A maintenance inspection should include checking the motor, blower, drain line, coils, operating pressures and temperatures, the return and supply lines, refrigerant levels and connections.
If you have a company come out, check to make sure that its technicians are licensed as HVAC contractors and that the company holds worker's compensation and liability insurance, to protect you of an injury or property damage occurs during the work.
If, as you say, your system seems to be working fine but the technician suggests expensive repairs or replacing your unit, get advice from a couple more companies before authorizing any work.
Most A/C systems should last 15 years, provided they've been well taken care of.