One Symptom, Several Possible Causes
The awkward truth of this trade is that the faults do not map neatly onto the complaints. A house that is not getting cold enough could be short of refrigerant, short of airflow, carrying a fouled outdoor coil, running a compressor that has lost capacity, or simply asking a correctly working system to do more than it was ever sized for.
Those five have five different prices and only one of them is right. Working out which is a measurement job, and skipping it is why so many households here have paid for refrigerant three summers running on a system that was never actually low. It is the reason AC Repair Wellington treats the diagnosis as the product and the repair as the consequence.
What Gets Measured
The same sequence every time, so nothing depends on how obvious the fault appears. Electrical values first, because they are quick and they rule out the cheap answers. Then the refrigeration circuit, then air movement, then the condensate side.
Numbers get compared against the manufacturer data for your specific equipment rather than against a rule of thumb, which matters more than it sounds — a subcooling figure that is perfectly healthy on one system indicates a real problem on another.
- Supply and return temperatures, and the split between them
- Suction and liquid pressure, each read back as a saturation temperature
- Superheat and subcooling calculated and checked against the data plate
- Total external static pressure across the air handler
- Running amps on the compressor, condenser fan and blower motor
- Capacitor values, contactor condition and voltage at each stage
- Drain line flow, pan condition and float switch operation
What You Are Told Afterwards
The findings come back in plain language: what the readings show, what is causing it, what fixing it involves, and what happens if you leave it. Where there is more than one reasonable option, you get all of them with prices rather than the one we would prefer to sell.
You also get told what is fine. A report that lists only problems is a sales document, and a system where three things are healthy and one is failing should be described that way.
Repairs That Follow
Most of what a diagnosis turns up is ordinary and gets fixed the same visit: capacitors, contactors, fan motors, blower assemblies, float switches, transformers, thermostat wiring, drain blockages and control boards.
Larger work — a coil, a compressor, a full changeout — is quoted rather than started, so nobody is making a five-figure decision while a technician stands in the hallway waiting. The diagnostic findings belong to you either way, and you are free to take them elsewhere for a second price.
Questions We Get Asked
- Why not just replace the part that usually fails?
- Because "usually" is doing a lot of work in that sentence. Swapping the common part fixes it perhaps half the time, and the other half you have paid for a component that was never faulty and still have the original problem to solve.
- How long does a full diagnosis take?
- Between forty-five minutes and an hour and a half on most residential systems. Longer where the air handler is awkwardly located, where the fault is intermittent, or where the ductwork has to be inspected as part of the picture.
- Do I get the readings if I do not go ahead?
- Yes. You paid for the diagnostic, so the findings are yours, written down, whether you have us do the work or not. We would rather be judged against another quote than rely on you not getting one.