Thermostat & Controls Services, Georgetown TX
Thermostat Installation & Service
Install any thermostat, standard, programmable, or smart, with proper wiring, configuration, and testing.
Replace faulty or outdated thermostats. We identify compatibility requirements before recommending equipment.
Recalibrate thermostats reading inaccurately, a 2-3°F offset causes significant comfort and efficiency problems in Georgetown's heat.
Determine if the thermostat or the system is the cause of HVAC problems, the thermostat is rarely the actual culprit.
Relocate thermostats away from heat sources, drafts, or direct sunlight that cause inaccurate temperature readings.
Install a common wire for smart thermostats that require continuous 24V power, without it, smart thermostats often malfunction.
Full smart thermostat setup including wiring, app configuration, scheduling, and compatibility verification.
Optimize thermostat response settings, anticipator adjustment, and stage sequencing for your specific system.
HVAC Electrical Diagnostics & Repair
Systematic low-voltage and line-voltage electrical diagnosis, find faults without replacing working components.
Repair damaged, corroded, or incorrectly wired HVAC control and power circuits.
Diagnose and repair HVAC power supply issues, breakers, disconnects, and line-voltage components.
Correct overcurrent or undersized circuit conditions causing tripped breakers or component damage.
Recover HVAC systems stuck in lockout, error states, or post-power-surge conditions.
Trace and repair 24V control circuit faults, shorts, opens, and incorrect wiring between thermostat and equipment.
Repair or replace outdoor AC disconnect boxes, fuses, and weatherhead connections.
Replace deteriorated flexible conduit and wiring connections at outdoor AC units.
HVAC Control Components
Diagnose and repair HVAC control system failures including boards, relays, and communication wiring.
Full system calibration, thermostat, controls, and equipment operating parameters aligned and verified.
Calibrate system staging, fan delays, and operating behavior for your specific comfort and efficiency goals.
Calibrate control signals between thermostat and equipment, staging, modulation, and communication signals.
Replace failed 24V control transformers, the power supply for the entire low-voltage control circuit.
Replace failed relay boards that control equipment staging and multi-zone operation.
Install safety disconnect switches for code compliance and service safety on HVAC equipment.
Replace aquastat controls on hydronic and boiler systems that regulate water temperature.
Install and configure zone control panels for multi-zone HVAC systems.
Install outdoor temperature sensors for weather-compensating controls and smart thermostat systems.
When Relay Boards Fail and How We Replace Them
Relay boards are dedicated circuit boards, separate from the main control board, that handle switching for specific functions like fan staging, zone damper operation, or auxiliary equipment like electric heat strips. They're common on multi-stage systems and zoned HVAC installations where the main control board doesn't have enough onboard relays to handle every switching function the system needs, so a secondary relay board takes on that load.
These boards fail primarily through relay wear, the same electromechanical contact degradation that affects any relay, but concentrated on a board that may be switching several different loads simultaneously. A relay board serving a zoned system, for example, might control dampers for three or four zones plus fan staging, and heavy use in one zone accelerates wear on that specific relay while others on the same board remain fine, which produces the confusing symptom of one zone working normally while another doesn't respond, even though both are controlled by the same physical board.
Our diagnostic process identifies which specific relay or output on the board has failed before assuming the entire board needs replacement, since some relay boards allow individual relay module replacement rather than swapping the whole assembly. We test each relay's contacts under actual load with the system running, checking whether the relay closes reliably, holds under sustained current, and releases cleanly when the call ends, rather than just checking for continuity with the system off, since some failures only appear under real electrical load.
When full board replacement is necessary, we verify the exact model and revision match the original, since relay boards on zoned and multi-stage systems often aren't universally interchangeable the way a simple furnace control board might be, wiring harnesses and connector pinouts vary between board revisions even within the same manufacturer's product line. Georgetown homes with retrofitted zoning, where a zone panel and relay board were added to a system years after original installation, are where we most often find mismatched or improperly rated relay boards that were installed as a quick fix rather than a proper match to the system's actual load requirements, and correcting that mismatch is often necessary for a lasting repair rather than a temporary one.
Frequently Asked Questions, HVAC Relay Board Replacement
HVAC Electrical or Thermostat Issue?
We trace faults to the actual source, not replace parts until something works.