Setpoints
Comfort in most homes sits around 68–72°F in heating season, with a similar range in cooling. Setback only works if the system can recover on its own instead of leaning on auxiliary heat for hours.
Split Cooling and heating in Poway, California
Poway Pro HVAC Repair services both halves of a Poway home: air conditioning repair and replacement, gas furnace and heat pump heating, plus the thermostats, ductwork and airflow that decide whether each room gets the air it was designed for.
Side 01 — Cooling
Condenser, evaporator coil, blower motor and refrigerant charge, treated as one circuit.
Side 02 — Heating
Burner, heat exchanger, inducer, ignition and blower, tested in the order they fire.
01 Cooling services
An air conditioner that will not hold temperature usually has one measurable cause. Work starts at the thermostat, then follows the circuit through the condenser, the line set, the evaporator coil and the blower, with readings taken before anything is replaced.
Suction and liquid line temperatures, superheat and subcooling, condenser coil condition and fan operation. A system that reads low on refrigerant has a leak somewhere on the circuit, and a leak is found rather than topped off.
Airflow comes first: filter load, blower wheel condition, collapsed flex duct, registers closed off in the room. Ice points at low airflow or low charge, so the system is shut off to thaw before either is measured.
Condensate pan level and condition, drain line clear, float switch wiring, and the state of the evaporator coil sitting above the pan. A pan that cannot drain will find the ceiling instead.
Charge, condenser airflow, low and high pressure controls, and thermostat placement. A unit that starts and stops quickly never runs long enough to pull moisture out of the air.
Register output in CFM, the length and condition of the branch run, and the return air path for that room. The equipment can be healthy while the duct feeding the room is not.
Contactor points pitted or burnt, capacitor tested under load, fan motor amp draw and bearing noise, plus fin damage on the coil face.
02 Heating services
Most heating calls fall into three groups: the furnace never lights, it lights and then quits, or the far rooms stay cold. Each points to a different part of the sequence, so the sequence is tested in order instead of guessed at.
Thermostat call and power, hot surface ignitor resistance, flame sensor microamp reading, gas valve pressure and the inducer pressure switch. Whichever step stops is the step that gets repaired.
High limit and rollout switches, temperature rise across the heat exchanger compared with the rating plate range, filter condition, blower wheel and how many registers are actually open.
Sizing against the real load, thermostat location relative to supply air, and whether second stage or auxiliary heat is carrying more of the recovery than it should.
Duct sizing and insulation on long runs, damper positions, and whether the return for that room is shared with a space that keeps its doors closed.
Heat exchanger condition, combustion air openings, flue draft and vent connections. Soot is a sign of incomplete combustion, not a cleaning item.
Leave the house and reach emergency services or the gas utility first. Heat exchanger, venting and combustion air are inspected before the equipment is fired again.
03 Heat pumps
A heat pump runs the same refrigerant cycle as an air conditioner, in both directions. A reversing valve moves the heat, a defrost board keeps the outdoor coil from loading with frost on cold mornings, and auxiliary heat covers the gap while the coil recovers.
A Manual J load calculation, then capacity checked at the design temperature. Square footage rules of thumb produce equipment that short cycles or never keeps up.
R-410A on most installed equipment and R-454B on newer systems. Line sets are brazed with nitrogen, evacuated to a deep vacuum and weighed in to the charge.
Defrost cycles temporarily reverse the system to clear the outdoor coil. Heat strips or a gas furnace carry the load while that happens, so the thermostat does not see a dip.
Wall units, ceiling cassettes and floor consoles with a line set through the wall. Dual fuel setups switch between the heat pump and the furnace on outdoor temperature.
04 Thermostat controls
A thermostat is a low-voltage device with a long reach. Setpoint, staging, schedule and sensor placement decide how long the equipment runs, and wiring mistakes show up as contactor failures long before the display does.
Comfort in most homes sits around 68–72°F in heating season, with a similar range in cooling. Setback only works if the system can recover on its own instead of leaning on auxiliary heat for hours.
Two-stage and variable-capacity equipment needs a control that calls for second stage. A single-stage thermostat leaves the rest of the capacity unused and turns the system into an on-off machine.
Modern thermostats expect a common wire. Missing or mis-wired common shows up as reboot loops, a blank display, or a system that drops out mid-cycle.
A control on a sunlit wall or directly above a supply register reads the room wrong. Remote and return-air sensors give the system a number that reflects the space it is serving.
Hold, schedule and occupancy modes behave differently from each other. A share of comfort complaints are a schedule that was never set for how the house is actually used.
Zone panels stage the equipment off the zones they serve. When dampers close, duct static pressure rises, so a bypass or a variable-speed blower has to be part of the design.
05 Ductwork
Equipment ratings describe the box, not the rooms. Duct sizing, static pressure and leakage decide whether the air that leaves the unit ever reaches the register at the far end of the run.
An undersized or leaking branch run, a damper left closed, or no return path for that room at all. Balancing only helps once the duct can carry the air.
Leaking return boots and unsealed joints pulling air from an attic or crawlspace instead of from the rooms. Cloth duct tape does not count as a seal.
Velocity too high for the boot size, or a downstream damper closed. Low velocity at the end of a long run usually means the run was never sized for the CFM it was given.
Filter surface area and return air sizing. A one-inch filter in a small cabinet adds resistance quickly; a four-inch media cabinet gives the blower more room to work.
Compression at the takeoff, sag between supports and crushed sections. Flex has to run with slack and a proper bend radius to deliver what the design called for.
06 Maintenance
Dirty coils, a loaded filter and a neglected drain pan cause most repeat calls. Servicing cooling and heating together keeps the readings side by side, so a change from one season to the next is visible instead of remembered.
Cooling season
Heating season
Readings taken and written down
07 Indoor air quality
Air quality work is filter media, humidity, ventilation and monitoring, in that order of impact. Plenty of complaints turn out to be an airflow or sizing problem wearing a different name.
MERV rating has to fit the cabinet and the static pressure the blower actually has available. A filter that captures more and starves the coil shows up as a frozen evaporator, not as clean air.
Residential comfort generally sits between 30% and 50% relative humidity. Summer moisture is removed by runtime, and a system that short cycles never stays on long enough to dry the air.
Tight houses still need outdoor air. Exhaust only, supply only or balanced ventilation is chosen by what the house already does, and the intake location matters as much as the rate.
What the filter does not catch settles on the evaporator coil and in the drain pan. A pan that stays wet between visits is the smell people describe as the air conditioner.
Gas appliances and attached garages make carbon monoxide detection a safety item rather than an accessory. Alarms are checked for placement and age when the heating system is serviced.
08 Equipment index
A working index of the equipment that comes through the door. If the rating plate is visible, the model and serial numbers help bring the right parts on the first visit.
Outdoor condenser, line set, evaporator coil and the air handler or furnace cabinet it sits with.
Upflow, downflow and horizontal cabinets, condensing and non-condensing, rated by AFUE.
Single-speed and inverter driven, with reversing valve, defrost board and auxiliary heat.
Wall units, ceiling cassettes and floor consoles served by a line set and a condensate drain.
Packaged split and RTU equipment on low-rise commercial and light industrial buildings.
Blower, coil, filter rack and controls — the part of the system that moves the air.
Conventional and communicating controls, zone panels, dampers, remote sensors and low-voltage wiring.
Sheet metal, flex and trunk-and-branch layouts, returns, boots, dampers and insulation.
Media and media-cabinet filters, fresh-air intakes, exhaust fans and make-up air.
Pans, float switches, drain lines and condensate pumps, checked on every cooling visit.
09 Contact
Call or email with the symptom, the system type and the model number from the rating plate if you can see it. If there is water on the floor, a burning smell or an active carbon monoxide alarm, say so on the call — it changes what gets brought to the visit.