OEM Carrier Furnace Control Board HK42FZ034 for PG8UAA024045ADJA

The HK42FZ034 integrated furnace control board is the electronic brain of your Carrier PG8UAA024045ADJA packaged gas unit. It sequences every ignition cycle — energizing the inducer motor, proving the pressure switch, powering the hot surface igniter, opening the gas valve, and timing blower on/off delays — while continuously monitoring flame through the sensor. When this board fails the symptoms are unmistakable: the furnace ignites then short-cycles, the blower runs constantly or never starts, you get no heat at all, or the unit locks out and flashes a diagnostic LED error code. Intermittent no-heat calls on cold mornings, scorched relay contacts, and a faint burnt-electronics smell are classic signs of a degrading board. This board carries multiple onboard relays (typically driving the inducer, blower-heat, blower-cool, and electronic air cleaner / humidifier terminals) plus a 3-amp automotive fuse and a self-diagnostic LED. It is matched to the 8UA / PG8UAA cabinet's wiring harness and 24V transformer secondary; the pin-out and ignition-timing firmware must match the original or the sequence will not complete. Why OEM matters: aftermarket "universal" boards often use generic relays with lower contact ratings and approximate ignition timings that don't match Carrier's flame-proving window. The result is nuisance lockouts, premature relay pitting, and igniter overheating. The genuine HK42FZ034 is flashed with the exact factory sequence and built to the original component ratings. Install difficulty: 4 of 5. Tools: 1/4" nut driver, Phillips screwdriver, needle-nose pliers, and a multimeter; photograph the wiring before disconnecting anything. SAFETY: kill the breaker to the unit before touching the board — 120V is present at the line terminals even with the thermostat off. Ships same business day from our stocked warehouse on orders placed before 3 PM CST. Backed by a 1-year OEM warranty and 30-day hassle-free returns on uninstalled parts.

Compatibility

This part is compatible with Carrier model PG8UAA024045ADJA. Always verify the part number against your unit's data plate before ordering.

Why Choose OEM?

OEM parts are manufactured to the exact factory specifications for your unit. Generic aftermarket alternatives may fit physically but often use lower-rated components that reduce equipment life and void manufacturer warranties. When the cost difference between OEM and generic is $10-30, the OEM part is always the smarter investment on a system worth $5,000-$15,000.

Shipping & Returns

Same-day shipping on orders before 3 PM CST. Standard delivery 2-5 business days, express options available at checkout. 30-day hassle-free returns on uninstalled parts — free return shipping included. 1-year OEM factory warranty coverage.