Equipment
- Air Handler: 5-Ton AMST60U1300A, 115/208-230V, Multi-Position, R-32
- Condenser: 5-Ton Goodman GLZS4BA6010A Heat Pump, 208-230V, R-32, SEER 15, EER2 12.5
- Materials: power line, disconnect box, whip/conduit/fuses, lineset, smart thermostat, surge protector, gas leak sensors, emergency switches, new plenum, pad
The starting situation
A Union City homeowner called in January with an aging gas furnace and a separate AC unit that had finally given up after twenty-plus years. Both were single-stage, both were oversized for the house, and both were running on a 1990s split-system layout that had been patched a dozen times. The PG&E bills told the rest of the story.
They wanted to replace the AC. We talked them through the math on going further, pulling the gas furnace out at the same time and switching the whole house to a heat pump. Two reasons it made sense for this house specifically: their existing electrical panel had room for the dedicated 240V circuit, and switching the whole house to a heat pump covers heating and cooling off one system. On operating cost the heat pump beat replacing the AC alone well inside the equipment’s service life. Where utility rebates apply, we confirm what is actually paying at estimate time.
What we installed
- Condenser: 5-ton Goodman GLZS4BA6010 heat pump, 14.3 SEER2 / EER2 12.5, running on R-32 refrigerant
- Air handler: matched 5-ton AMST60DU1300, multi-position, factory R-32 charge
- Power side: new dedicated 240V circuit, disconnect box, weatherproof whip, fuses sized to the condenser nameplate
- Refrigerant: new lineset (the old copper was R-22-era and not worth pressure-testing for a 30-year service life)
- Controls: smart thermostat with heat-pump-aware staging, surge protector on the high-voltage side, emergency disconnect at the air handler
- Safety: gas leak sensors at the former furnace location (we left the gas line capped at the meter but added sensors for the kitchen runs that stayed live)
- Mounting: new composite condenser pad set on compacted gravel, level to spec, the original AC had been sitting on a cracked slab that was telegraphing vibration into the family room wall
The detail that mattered
The plenum from the old furnace was undersized for a 5-ton air handler’s CFM, so we built a new transition plenum on-site. This is the kind of thing that’s easy to skip, bolt the new air handler to the old plenum and call it done, but it’s the difference between rated efficiency and the system running noisy at 80% of spec for the next fifteen years. If your installer is quoting a one-day heat pump swap and not mentioning the plenum, that’s worth asking about.
What the homeowner got
Power-on, system was up and balanced within the first run cycle. The smart thermostat handles staging automatically, the homeowner doesn’t have to think about cool/heat changeover. First month’s electric bill came in about where we projected for January (Union City is mild enough that resistance backup almost never kicks in). Equipment is under our standard 10-year parts warranty plus a labor warranty (2 years standard, extended to 10 years with our maintenance plan) on the install side, subject to your contract terms, plus the Goodman factory warranty on the unit itself.
The full-quality photos below show the before state (the old equipment we pulled out) and the finished install, condenser, electrical, and air handler.
Before
After
