AC Repair in Watkins, Colorado

Cooling failures on the eastern edge of Adams County land on the electrical side of the system more often than the refrigerant side. Contactors, capacitors and motor windings are what stops working out here, and the tests that find them take a meter and a clamp rather than a set of gauges. MoJo Home Services covers Watkins at 5,525 feet, licensed, insured and EPA-certified. The number is 720-807-4050.

What voltage should a Watkins condenser actually see?

A residential outdoor unit is nominally 240 volts, and equipment is rated to run within about ten percent either side of its nameplate figure. The reading that matters is taken at the disconnect with the compressor running, not with the system idle. Voltage that looks fine at rest and sags on start-up tells a different story than voltage that is simply low all day. Low supply voltage under load raises current draw, because a motor asked to do the same work at reduced voltage pulls more amps to get it, and heat follows the amps into the windings.

Why does the contactor fail so often on Watkins equipment?

A contactor is an electromagnet holding two contacts together against spring pressure. If the 24-volt coil voltage sits at the low end, the armature does not seat firmly and chatters, and every chatter is a small arc across the contact faces. Those faces then pit, pitting raises resistance, resistance makes heat, and heat welds or burns them. By the time a homeowner hears buzzing at the outdoor unit, the contact surfaces usually tell the story visually. Measured coil voltage and measured voltage drop across the closed contacts separate a failing contactor from a failing control transformer.

What does 5,525 feet add to the current draw?

Watkins air is about 15.2% less dense than sea-level air. The condenser fan moves its rated cubic feet per minute but carries less mass through the coil, so heat rejection suffers, condensing temperature climbs and the compressor works against higher head pressure. Higher head pressure means higher amp draw. On a marginal system the clamp reading creeps toward the rated load amps on the nameplate and the internal overload starts opening on the hottest afternoons. Indoors, the corresponding correction is about 472 CFM per ton rather than the 400 in the tables. Gas equipment separately gives up 14.1% of rated output at this elevation.

What does exposure do to an outdoor unit east of the metro?

Equipment on open ground takes weather from every direction with little in the way of windbreak. Wind-driven grit works into fan motor bearings and across contactor faces, sun exposure runs the control compartment hotter than a shaded unit ever gets, and capacitors are electrolytic devices whose service life falls as their operating temperature rises. That is why a capacitor out here can drift below its rated microfarads years before one in a shaded metro side yard. It is also why we check the measured capacitance rather than the printed value on any Watkins service call.

What does a Watkins service call measure?

Supply voltage at the disconnect while running. Control voltage at the contactor coil. Voltage drop across the closed contacts. Run capacitor microfarads against the stamped rating for both compressor and fan. Compressor amp draw against rated load amps, and fan motor amps against its own plate. Then, only when the electrical side is clean, the refrigerant readings: superheat, subcooling and condenser approach. Running the sequence in that order stops a technician from adding refrigerant to a system whose actual complaint is a capacitor that can no longer start the motor.

Does being out at Watkins change what a repair takes?

It changes what a truck needs to carry. Distance from the metro core rewards arriving with common contactors, capacitors, condenser fan motors and disconnect fuses on board, because the difference between a completed repair and a return visit is usually one commodity part. It does not change the diagnostic standard. The readings taken at a Watkins address are the same ones taken in Aurora, recorded and explained the same way.

The eastern corridor

We run this side of Adams and Arapahoe together: Bennett further east, Aurora Highlands south, and the rest of Aurora on the way back in.

Same crews, neighbouring towns

The same trucks run AC repair in Bennett, AC repair in Aurora Highlands, AC repair in Aurora on the same rotation.

Heating and cooling fail for different reasons in the same house — see furnace repair in Watkins.

More on the service itself: AC repair.