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Cooling and heating for McKinney houses
Two-storey houses with the plant in the attic, a cooling season that runs most of the year, and ductwork that was signed off but never balanced.
Checked in the order that costs you least
This is the order we work in. The entries at the top fail most often here and cost the least to put right.
Capacitor and contactor
The two cheapest parts on an outdoor unit and the two that fail most in this heat. A unit that hums but will not start is usually one of them.
A blocked coil
Pollen, grass and construction dust load a condenser fast in a developing area. It quietly halves what the unit can do and raises the bill every hour it runs.
Condensate
A blocked drain trips the float switch and the system stops with nothing apparently wrong. That switch is the only thing standing between the attic and your ceiling.
Low charge
Measured, not topped up on sight. Refrigerant is not consumed — a system that wants more every year is leaking, and the leak is the job.
A frozen coil
Low airflow or low charge. Switch the cooling off, leave the fan running, and call. Running a compressor with a frozen coil is how compressors fail.
The thermostat
Batteries, wiring and settings. A share of summer call-outs genuinely end here and we say so rather than finding something else to charge for.
The complaint, and the wrong answer
Upstairs unusable by mid-afternoon is the most common request in this market, and a bigger system is the most common answer offered. An oversized system short-cycles, never dries the air, and leaves the same room hot.
What actually settles it
- Airflow at the registers that are wrong, compared with one that is fine. Two numbers, half an hour.
- Static pressure across the system, which says whether the ductwork can carry what any new equipment would need.
- The return path with the doors shut. A bedroom that behaves with the door open and not with it closed is a return problem, not a capacity one.
- Duct leakage, tested rather than inspected.
And what is not ours
Attic insulation, attic ventilation and radiant barrier all matter enormously in this climate and they are an insulation contractor’s work, not ours. Where that is the real answer we will say so rather than selling around it.
Short winters, real bills
Gas furnaces are combustion tested with an analyser and the readings written down. On a heat pump the two things worth looking at are the defrost cycle and the auxiliary heat — a heat pump running on auxiliary electric heat through a cold snap will keep the house warm and produce a bill nobody can explain.
What a replacement quote is built from
- A room-by-room heat gain and heat loss calculation, from the actual construction and orientation — not floor area and not the old unit’s rating.
- The measured capacity of the existing ducts. If they cannot carry what the new equipment needs, better equipment makes the house worse.
- The condensate route, the pan and the float switch.
- The electrical supply, read off the plate of the proposed unit.
- One page with model numbers, capacities, what is removed, what is altered, and the price.
Gas, or a carbon monoxide alarm
Do not ring a contractor first. Get everybody out of the house and, from outside, call 911 and your gas utility’s emergency line. They arrive faster than any contractor, they do not charge you for a false alarm, and making the property safe is their job. Ring us afterwards — finding out why it happened is ours.
Commissioning, late
Balancing the airflow room by room and verifying the charge under real conditions is the step that gets skipped at handover on a production house. It can be done afterwards, it costs a fraction of replacement, and on a house you intend to keep it is the best money available.