The short answer
Describe what your AC is doing, and the likely cause narrows quickly: no cooling at all often points to electrical parts, weak cooling to airflow or refrigerant, and water leaks to a clogged drain. We test, explain the fault and repair it.
Milpitas is close enough to our San Jose base, about 4 miles to the northeast, that cooling problems in ZIP 95035 are a short drive for us. What we find when we arrive varies with the house. Garage furnaces with a coil on top, attic air handlers in two-story tract homes, closet units in townhomes, and ductless heads in condos each fail in their own ways. ReliableAir HVAC Services repairs all of them. To help you describe the problem and know what we will look at, here is a symptom-by-symptom guide to AC trouble in Milpitas homes.
Symptom: the outdoor unit will not start
If the indoor fan runs but the condenser outside stays silent, the cause is usually electrical. A failed run capacitor, a burned contactor, a tripped breaker or a blown fuse at the disconnect are the common suspects. Low-voltage wiring that runs along a fence or through a garden bed can also be damaged by landscaping. We test each part with the system under a call for cooling, then find out why it failed. A capacitor that keeps burning out may be telling us the compressor is drawing too much current.
Symptom: cooling, but not enough
Weak cooling is the most common complaint in two-story Milpitas homes, especially upstairs on a hot afternoon. The causes split into two groups. Airflow problems include a dirty filter, a dusty evaporator coil, a weak blower and leaky or crushed ducts in the attic. Refrigerant problems come from leaks at the coil, fittings or valves.
We measure the temperature drop across the coil, the system pressures and the blower's airflow to tell these apart. If refrigerant is low, we find the leak before recharging. If airflow is the problem, more refrigerant would only make things worse.
- Ice on the copper line or the indoor coil
- Supply air that feels cool but not cold
- The system runs constantly and never reaches the setpoint
- Big temperature difference between upstairs and downstairs
Symptom: water where it should not be
Air conditioners remove moisture, and that water drains through a condensate line. In attic and closet installations, a clogged drain can overflow a pan and stain a ceiling or soak a floor. Many systems have a float switch that shuts the AC off before that happens, which can look like a sudden failure. We clear the drain, flush it, check its slope and confirm the safety switch works.
In condos with ductless systems, a leak from an indoor head is often a blocked drain hose or a head mounted slightly out of level.
Symptom: noise, smells or short cycling
A grinding or squealing sound usually points to motor bearings. Rattling can mean loose panels or debris in the condenser fan. A burning smell suggests an overheating motor or wiring, and the system should be turned off until it is checked. Short cycling, where the system turns on and off every few minutes, can come from an oversized unit, a thermostat placed in a draft or sun, a refrigerant issue, or a safety switch tripping. Each of these has a clear test, and we work through them in order.
Townhome and condo considerations
For units in HOA communities, repairs sometimes require roof access or coordination with building management. Let us know when you book if your outdoor unit is on a roof or in a shared equipment area. If a repair is not cost-effective, for instance on an older system using R-22 refrigerant with a major leak, we will say so and explain replacement options, including a heat pump that handles heating as well. Bay Area Air District rules do not require replacing working equipment, so the decision stays yours.
Shared walls also change how we think about noise and airflow. In a townhome, an outdoor unit mounted close to a neighbor's bedroom window can draw complaints if a fan blade is bent or a mounting bracket has loosened, so we check isolation pads and fasteners along with the electrical parts. Closet air handlers in these homes frequently have a single small return grille, and a filter that looks only slightly dusty can still restrict airflow enough to freeze the coil on a warm day. We look at the return path, the filter size and the closet door clearance, because sometimes the lasting fix is as simple as a larger filter or a louvered door rather than a new part.
Our AC repair service also covers Fremont, Santa Clara, Sunnyvale, Newark and Mountain View.
More services in Milpitas
- Heating Repair in Milpitas
- Heat Pump Installation in Milpitas
- AC Installation in Milpitas
- Furnace Repair in Milpitas