Air conditioner repair in Norwood

If the air conditioner trips its breaker, reset it once. If it trips again, leave it off. Resetting it over and over can turn a failed capacitor or a shorted fan motor into a burnt-out compressor, which is the most expensive part in the system.

The usual causes are a weak or failed start capacitor, a pitted contactor, a seized condenser fan motor or a compressor that is drawing too much current as it starts. A dirty outdoor coil makes all of these worse, because the compressor runs hot. The technician checks the capacitor and the motors with a meter, looks at the wiring at the disconnect and the contactor, and measures the compressor's current draw before saying what failed.

Before you call, note whether the outdoor unit hummed, clicked or stayed silent before the breaker went. That narrows it down.

Frost on the larger copper line at the outdoor unit, or ice on the coil above the furnace, means the indoor coil is running too cold. Turn the cooling off and run the furnace fan on its own for a few hours to thaw it. Do not chip the ice off.

Most of the time the cause is airflow: a clogged filter, closed supply registers or a blower that is not running at the right speed. Check the filter first. If the filter is clean and the coil still freezes, the system is probably low on refrigerant, and refrigerant does not get used up. Low refrigerant means a leak. The technician finds the leak, tells you whether it can be repaired, and charges the system to the correct level only after that. Topping up a leaking system just puts off the same call.

Central air pulls water out of the house air at the indoor coil. That water runs to a drain pan, then through a small drain line to a floor drain or a condensate pump. When the line clogs with slime or the pump fails, water backs up and spills around the base of the furnace.

Check whether the condensate pump has power and whether its tank is full. If it is full and not pumping, the pump or its float switch has failed. If there is no pump, look for a kinked or blocked drain line. A coil that froze and then thawed can also overflow the pan.

The technician clears the drain and the trap, checks the pan for rust or cracks, tests the pump and confirms the water is draining before leaving. On a high-efficiency furnace, the furnace and the air conditioner often share the same drain, so a blockage can stop both.

If the indoor fan runs but the air is not cool, go outside. If the outdoor fan is not spinning, or the unit is silent, the fault is usually the capacitor, the contactor or the fan motor. If the unit is running but caked with grass clippings, cottonwood fluff or leaves, the coil cannot shed heat and the house will not cool on a hot afternoon. Hose the coil gently from the inside out with the power off.

Also check that the thermostat is set to cool, the set point is below room temperature and the batteries are good. Check both the breaker in the panel and the disconnect beside the outdoor unit.

If the system runs constantly and the house still sits a few degrees warm, the cause may be low refrigerant, a failing compressor valve, or ductwork that cannot move enough air to the upstairs rooms.

Most homes in the village are more than forty years old. Houses on the old Keeler's Mill lots were built long before central air, and the ducts were added later for a furnace. Those ducts are often undersized for cooling and poorly sealed, so upstairs bedrooms stay warm and the coil can freeze from low airflow. A repair fixes the fault; it will not fix the ducts. Where the ducts cannot carry cooling, the technician will say so, and ductless air conditioning may be the better answer.

Newer homes in Norwood Park and Phase 4 off Albine Street have tight construction, small duct runs and ventilation units. Problems there usually come from how the system was set up: an oversized air conditioner that short-cycles and leaves the house clammy, airflow that was never balanced, or a ventilation filter nobody has changed. The technician checks the set-up as well as the parts.

Work is performed by 313A refrigeration and air conditioning mechanics. The technician confirms what the system is doing, checks the electrical parts, the airflow and the refrigerant pressures, and shows you what failed. You get a written price for the repair and approve it before any part goes in. The aim is to get the system running again within the season, so a July fault does not cost you the summer.

If the system is old and the fault is a compressor or a large leak in the coil, a repair can cost a large share of a new unit. In that case you get both numbers: the repair and a replacement. How long a central air conditioner lasts explains why some repairs cost more than others. A yearly maintenance visit catches a weak capacitor or a slow drain before it stops the system.