Commissioned to Perform: The Ultimate Startup Checklist for 5-Ton R-32 HVAC Combos

🎤 Hey There: Don’t Flip That Switch Yet – Mark’s Startup Sermon

Alright, y’all—Mark here, back in the saddle with another dose of HVAC tough love.

Let me ask you something: if you just spent thousands of bucks and hours of blood, sweat, and maybe a few choice words installing a 5-ton R-32 combo system, why in the name of combustion would you not spend 90 minutes making sure it runs perfectly?

Too many folks rush this part. Flip the disconnect, wait for cold air, call it good. But lemme tell ya—startup and commissioning is where the magic (and the money) lives. It's where you verify that everything is installed, wired, charged, grounded, drained, and flowing like it should.

Miss a step, and you’ll be back next month fixing noisy blowers, short cycles, high head pressures, or flame sensor lockouts.

So I’m laying out the full startup and commissioning checklist for your 5-ton R-32 AC and gas furnace combo system. Print it. Laminate it. Tattoo it, if you have to. Because this is what separates pros from the part-timers.

Let’s bring this system online the right way.

 

🛠️ Visual and Mechanical Pre-Checks

Before we power anything up, start with a full visual and mechanical inspection:

• Confirm line set connections are torqued and insulated

• Verify condensate drain is sloped and secure

• Check that duct connections are sealed (use mastic or UL 181 tape, not duct tape)

• Make sure unit is level and clear of obstructions

• Confirm electrical disconnects are properly mounted and labeled

• Inspect gas line and leak test all joints with bubble solution

Need a visual guide? HVAC Training 101 offers a printable HVAC installation checklist worth having in your back pocket.

 

⚡ Electrical Verifications

Now it’s time to verify electrical setup:

• Confirm breaker sizes: typically 40A 2-pole for condenser, 15A or 20A for furnace

• Check wire gauge matches breaker sizing (e.g. #8 AWG for 40A)

• Confirm correct polarity and ground at furnace and disconnects

• Test voltage at line and low-voltage terminals

• Tighten all lugs and terminal screws—torque them to spec

• Check thermostat wiring: correct color, tight terminals, no exposed copper

If you need a refresher on electrical sizing, the ESFI Home Electrical Guide is a goldmine for safety basics.

Pro tip: Pull out the multimeter and record line voltage and 24V control power before system start. If something fails later, you’ve got baseline readings to work from.

 

💧 Drainage and Condensate Management

Nothing wrecks an install faster than water running down a furnace cabinet or shorting out a control board.

Checklist:

• Ensure primary and secondary drain lines are free of obstructions

• Test slope: 1/4" per foot minimum

• Confirm drain trap is installed if required

• Test system by pouring water into primary pan

• If using a condensate pump, test float switch functionality

For a deep dive into drainage best practices, Energy Star's HVAC installation guidance breaks it down in detail.

 

🌀 Airflow Testing and Static Pressure

Your 5-ton system won’t work without airflow. Period.

• Check for clean filters (MERV 8–11 is a good balance)

• Confirm blower speed matches tonnage

• Use a manometer to measure static pressure across supply and return

• Target total external static pressure (TESP) of 0.5–0.8" WC

• Compare readings to system blower performance chart

• Adjust blower tap or ECM speed if necessary

Need a calculator or reference? The GreenHeck static pressure guide is a favorite in the field.

 

🔥 Gas Pressure and Combustion Analysis

Time to fire up the furnace:

• Measure inlet gas pressure with a manometer (target: ~7–10" WC NG)

• Measure manifold pressure per manufacturer spec (usually 3.5" WC NG)

• Perform combustion test: CO, CO₂, O₂, stack temp

• Check for flame rollout or noisy ignition

• Verify flame sensor reads 1.5–4.5μA DC

• Make sure flue pipe has proper pitch and clearance

If you don't have a combustion analyzer, you're flying blind. I recommend the Bacharach Fyrite InTech for techs on a budget.

 

❄️ Refrigerant Charge Verification (R-32)

With the furnace running right, let’s turn to the condenser and get the charge dialed in.

• Connect digital gauges and temperature probes

• Start system and allow to stabilize for 10–15 minutes

• Check suction and discharge pressures, superheat, and subcooling

• Compare against factory charge chart for R-32

• Add or recover refrigerant by weight using a digital scale

• Check line set length—add charge if over 15 feet (per manufacturer spec)

R-32 systems operate at higher pressure than R-22, slightly lower than R-410A, and have tighter tolerances. Accuracy matters. Refer to AHRI’s refrigerant safety and handling guide for best practices.

 

🌡️ Thermostat Function and Control Sequence

Confirm thermostat functionality:

• Cycle through heat, cool, and fan modes

• Verify staging if system is 2-stage or variable

• Confirm fan speed changes with thermostat settings

• Test any accessories: humidifier, UV light, dehumidifier

• Set temperature and fan run time defaults

• Explain system modes to homeowner, especially “Auto” vs “On” fan settings

Use this time to make sure the thermostat is level (for old-school mercury models) and calibrated.

 

🧾 Final Walkthrough and System Documentation

Before you pack up:

• Label all breakers, disconnects, and equipment

• Leave behind manuals, wiring diagrams, and warranty cards

• Log all startup readings: gas pressure, voltages, static pressure, refrigerant levels

• Take pictures of finished install and startup sheet

• Explain maintenance schedule to homeowner

• Schedule first filter change and tune-up visit

And most importantly: register the warranty. Goodman’s R-32 systems have strong warranties—but only if you fill out the paperwork. Don’t leave it up to the homeowner.

 

🧢 Final Thoughts: Dialed In, Locked Down – Mark’s Final Word on Commissioning

Look, I get it—startup and commissioning isn’t glamorous. Nobody’s filming Instagram reels of guys doing static pressure readings or tightening flare nuts to spec. But you know what is glamorous?

A system that runs like a dream. Quiet, efficient, dialed-in from the jump. A system that never throws a lockout in the middle of winter, never short-cycles, and never leaks a drop of condensate into the basement.

That’s what commissioning does.

It turns “installed” into “ready.” It protects the equipment, the customer, and your reputation. Skip it, and you’ll be doing call-backs. Do it right, and your installs become referrals.

If you're still shopping for a 5-ton R-32 system that’s built for performance and ease of setup, start here:
👉 The Furnace Outlet 5-Ton R-32 Combos

They’ve got matching equipment, documented specs, and customer support that actually answers the phone.

So go commission like a champ. Check the checklists, trust your tools, and take pride in a system done right.

Want more information about installing and troubleshooting your 5-ton system? Visit my guide right here!

Until next time,
– Mark Callahan 🧢🛠️
“Still torquing flare nuts, still yelling about static pressure, still proud of a quiet furnace startup.”