I live in an 8-year old townhouse, so my A/C unit is the same age. The plumber tells me I need a new contactor & coil assembly & that it is usually replaced about every 5-7 years. Is this true? Thanks for any help you can provide.

I live in an 8-year old townhouse, so my A/C unit is the same age. The plumber tells me I need a new contactor & coil assembly & that it is usually replaced about every 5-7 years. Is this true? Thanks for any help you can provide.
You got a very funny plumber hahahaha... the contactor (relay) its failure depend on how may time it cycle, usually it replace after it is broken or you could tell that it is about to break...

One of the most important things a person can do to properly maintain an air conditioner is to replace the contactor every 6 to 8 years. It's amazing how much better they run. Points become pitted, over time, as they open and close. As the effective cross-sectional area of the points gets cut in half, the resistance goes up by a square function; i.e. 4-fold. Then, the compressor motor is starved for current and can burn up. Prior to that happening, you might notice the furnace/air handler running (blowing warm air), but not the outside condenser unit. My recommendation is to make sure the contactor, run, and start capacitors are in great shape; annually oil both ports on the condenser fan motor with 15 drops of ISO 32 wt. turbine oil (some have sealed bearings), which is available at ACE Hardware; remove the condenser coil covers, gently using a hose to rinse away dirt and debris; and change filters often. If you do this, a quality system, such as Trane or Lennox, should last 25 to 30 years. Before attempting any work on an air conditioner, turn "Off" the thermostat, turn "Off" the breaker/AC disconnect going to the condenser unit, and turn "Off" the breaker going to the furnace.