FurnacesGas
Goodman CDVS960805CU Furnace Manual
Setup, everyday use, maintenance and troubleshooting for the 96.1% AFUE single-stage gas furnace, with verified specifications.
- AFUE96.1%
- FuelNatural gas
- ENERGY STAR regionU.S. South only
- Example yearly gas cost$780
About the Goodman CDVS960805CU
The Goodman CDVS960805CU is a 96.1% AFUE single-stage gas furnace, certified under the ENERGY STAR program.
Its AFUE of 96.1% means that over a typical heating season about 96.1% of the fuel it burns ends up as heat in your home, while roughly 3.9% is lost through the vent and in cycling losses. Reaching that level requires a condensing design: a secondary heat exchanger cools the combustion gases until water vapor condenses, recovering heat that older furnaces send up the chimney. The result is cool, moist exhaust vented through plastic pipe and a steady stream of acidic condensate that must be drained. That AFUE is higher than 59% of the 3,391 gas furnaces in our database.
ENERGY STAR lists this furnace as certified for the U.S. South only. It meets the southern criteria but not the stricter requirements that apply in northern states, where furnaces run many more hours. It will still heat a northern home efficiently, but rebates that require ENERGY STAR certification in your region may not apply — check with your utility before buying.
It uses a single-stage burner that always fires at full capacity — simple and reliable, though cycles are shorter and temperature swings slightly larger than with two-stage or modulating models. The model name identifies it as a communicating furnace, designed to work with the manufacturer's matching communicating thermostat and outdoor equipment for setup, diagnostics and staging control. It is also designated ultra-low NOx, a burner design required for new gas furnaces in parts of California and other areas with strict air-quality rules.
Specifications
| Brand | Goodman |
|---|---|
| Model number | CDVS960805CU |
| Fuel category | Gas |
| AFUE (heating efficiency) | 96.1% |
| Fuel type | Natural gas |
| Propane (LP) capable | No |
| Condensing design | Yes |
| Burner staging | Single-stage |
| Communicating controls | Yes |
| Ultra-low NOx | Yes |
| ENERGY STAR certified in | U.S. South only |
Safety information
- Install UL-listed carbon monoxide (CO) alarms on every level of the home and outside each sleeping area. Test them monthly and replace them at the end of the life printed on the alarm.
- If you smell gas, do not light anything or operate electrical switches, phones or appliances inside. Leave the building immediately and call your gas utility or 911 from outside. Do not return until they say it is safe.
- Furnace installation, gas or oil piping, venting and electrical work must be done by a licensed heating contractor following the manufacturer's instructions and local codes. Most jurisdictions require a permit and inspection.
- Never store gasoline, paint thinner, solvents, aerosols or other flammable products near the furnace, and keep the area around it clear of storage.
- Do not operate the furnace with the burner or blower access doors removed. The doors seal the combustion area, and a door safety switch cuts power when the blower door is off.
- Turn off power at the furnace service switch or breaker before changing the filter or opening any panel.
- Keep the outdoor vent and combustion-air terminations clear of snow, ice, leaves and nests. A blocked vent will shut the furnace down, and a damaged vent pipe can leak flue gases indoors.
Installation and first-time setup
Proper installation determines whether the Goodman CDVS960805CU delivers its rated efficiency safely. Use the checklist below when reviewing quotes and when the work is finished.
- Size it to the house
Ask for an ACCA Manual J heat-loss calculation rather than matching the old furnace's size. Oversized furnaces short-cycle, heat unevenly and wear out sooner. The calculation also tells the contractor how much airflow the ductwork needs to deliver.
- Location and clearances
Install the furnace in a location and orientation the installation manual allows, with the listed clearances to combustibles and enough room in front for service. Furnaces in attics, crawlspaces or garages need freeze protection for the condensate system and, in garages, protection from vehicle impact.
- Venting
Condensing furnaces vent through plastic pipe — PVC, CPVC or polypropylene, as the installation manual specifies — either as a single exhaust pipe or as a two-pipe direct-vent system that also brings in outdoor combustion air. Pipe must slope back toward the furnace (typically at least 1/4 in. per foot) so condensate drains, and terminations must meet the listed clearances from windows, doors, air intakes, gas meters and expected snow level.
- Do not orphan the water heater
A condensing furnace never shares the old chimney. If the previous furnace and a gas water heater vented together, the chimney may now be too large for the water heater alone and need a liner or other correction so it drafts safely. Ask the installer to check this.
- Condensate drain
Connect the factory trap to a floor drain, laundry sink or condensate pump. Many codes and manufacturers call for a neutralizer cartridge because condensate is acidic. Drain lines in unheated spaces need freeze protection.
- Gas supply
The gas line must be sized for the furnace input, with a manual shut-off valve and a sediment trap at the appliance, and every joint leak-tested with an approved solution or electronic detector — never a flame.
- Ductwork and airflow
The contractor should measure total external static pressure, set the blower speed taps for heating (and cooling, if an air conditioner shares the blower) and confirm that the temperature rise across the furnace is within the range on the rating plate.
- Commissioning
Ask for a written start-up report showing inlet and manifold gas pressure, temperature rise, combustion analysis (CO and O2 or CO2) and confirmation that all safety controls were tested.
Using your furnace
Thermostat settings
Furnaces recover quickly, so thermostat setbacks save fuel. The U.S. Department of Energy estimates you can save up to 10% a year on heating by turning the thermostat back 7–10 °F for eight hours a day, such as overnight or while you are at work.
What a normal heating cycle looks like
On a call for heat the draft inducer starts first and a pressure switch confirms the vent is clear. The ignitor then heats up, the gas valve opens and the burners light; a flame sensor proves the flame within a few seconds. The main blower starts after a short delay so cold air is not blown into the house, and it keeps running for a minute or two after the burners shut off to recover the remaining heat.
In cold weather a white plume of water vapor from the vent terminal is normal for a condensing furnace, as is the trickle of condensate into the drain.
Single-stage operation
A single-stage furnace fires at full capacity every cycle. If rooms feel drafty at the start of a cycle, ask your contractor to check the blower-on delay and airflow settings.
Fan setting
Leave the thermostat fan on "Auto" for the lowest electricity use: the blower runs only while the furnace is heating. "On" circulates air continuously, which can even out temperatures and improve filtration but uses more electricity and can feel drafty in winter.
Care and maintenance
| When | What to do |
|---|---|
| Every 1–3 months | Check the air filter and replace it when dirty (1 in. filters usually monthly to quarterly; 4–5 in. media filters every 6–12 months). A clogged filter is the most common cause of overheating and safety shutdowns. |
| Every month | Test CO and smoke alarms. During the heating season, glance at the furnace and listen for unusual noises. |
| During winter | After snowstorms, clear snow and ice from the vent and intake terminations outside. |
| Every year | Have the condensate trap, drain line and any neutralizer cleaned or replaced as part of the tune-up; a clogged trap is a leading cause of no-heat calls. |
| Every year, before the heating season | Professional inspection: burners, ignitor and flame sensor, heat exchanger(s), draft inducer, venting, gas pressure, combustion analysis, blower and all safety controls. |
| Every 5–10 years | Replace CO alarms according to the date printed on them. |
Troubleshooting
Many no-heat calls come down to the thermostat, the filter or a switch. Work through the checks below, but leave gas, oil, venting and electrical repairs to a qualified technician.
| Problem | Possible cause | What to try |
|---|---|---|
| No heat at all | Thermostat setting or batteries; tripped breaker; service switch off; blower door not seated; gas valve closed. | Check thermostat mode and setpoint, the breaker and the switch near the furnace; reseat the blower door; confirm the gas cock at the furnace is open (handle parallel to the pipe). |
| Blower runs but air is cold | Burners not lighting (ignition lockout); clogged filter causing high-limit shutdowns; condensate trap blocked. | Replace the filter and check the condensate drain. Turn power off for 30 seconds to reset a lockout once; if it recurs, call a technician. |
| Burners light, then shut off within seconds | Dirty or failing flame sensor; poor ground; low gas pressure. | Call a technician to clean or replace the flame sensor and check gas pressure. |
| Delayed ignition — a bang or rumble when burners light | Gas building up before ignition; dirty burners or ignitor problem. | Turn the furnace off and call for service; delayed ignition can damage the heat exchanger. |
| Short cycling (frequent on/off) | Dirty filter; blocked returns or registers; oversized furnace; thermostat near a heat source. | Replace the filter, open registers and clear returns. If cycling continues, have the contractor check temperature rise and sizing. |
| Status light blinking | The control board is reporting a diagnostic code. | Count the flashes and compare with the code label inside the furnace door or the code table in your manufacturer's manual. |
| Burning-dust smell at the first start of the season | Dust burning off the heat exchanger. | Normal for a short time. A persistent burning, electrical or rubber smell means shut the furnace off and call for service. |
| Water on the floor around the furnace | Clogged condensate trap or drain; failed condensate pump; frozen drain line; leaking vent joint. | Clear or thaw the drain and check the pump. Water from the vent pipe or a soaked cabinet needs a technician. |
Energy use and running costs
The examples assume a home that needs 50 million Btu of delivered heat per year — roughly a mid-size house in a cold northern climate. Scale the figures up or down for your home and climate. At 96.1% AFUE the Goodman CDVS960805CU would burn about 520 therms of natural gas, costing roughly $780 a year at $1.50 per therm.
| Furnace | Gas used | Estimated cost |
|---|---|---|
| This model (96.1% AFUE) | 520 therms | $780 |
| Federal minimum (80% AFUE) | 625 therms | $938 |
| Older furnace (65% AFUE) | 769 therms | $1,154 |
Compared with a minimum-efficiency 80% AFUE furnace, that is about 105 therms ($157) saved each year.
The furnace blower and draft inducer also use electricity, which is not included in these estimates.
Frequently asked questions
What is the AFUE rating of the Goodman CDVS960805CU?
The Goodman CDVS960805CU is rated at 96.1% AFUE, so about 96.1 cents of every fuel dollar becomes heat in your home over a typical season.
Can the Goodman CDVS960805CU run on propane?
The ENERGY STAR record lists it for natural gas only. Ask the manufacturer whether an approved propane conversion kit exists before considering LP.
Is the Goodman CDVS960805CU ENERGY STAR certified in northern states?
No. It is certified for the U.S. South only. It can still be installed in a northern home, but it does not meet ENERGY STAR's northern-region criteria, so northern rebates that require certification may not apply.
What kind of vent pipe does the Goodman CDVS960805CU need?
As a 96.1% AFUE condensing furnace it vents through plastic pipe (PVC, CPVC or polypropylene as the manual allows), in a single-pipe or two-pipe direct-vent arrangement, and needs a condensate drain. It must not share a chimney with other appliances.
How much gas will the Goodman CDVS960805CU use?
To deliver 50 million Btu of heat in a year it would burn about 520 therms, roughly $780 at $1.50/therm. Your actual use depends on your home's heat loss and climate.
Is the Goodman CDVS960805CU single-stage or two-stage?
Its model name identifies it as a single-stage furnace.
When was the Goodman CDVS960805CU ENERGY STAR certified?
It appears on the ENERGY STAR certified furnace list with a certification date of April 2026, certified for the U.S. South only.
Sources and disclaimer
Specifications on this page come from the ENERGY STAR certified furnaces dataset published by the U.S. Environmental Protection Agency (record certified April 26, 2026), retrieved October 7, 2026.
The setup, operating, maintenance and troubleshooting guidance is written by ManualHarbor's editors for this specific product type and configuration. It is an independent guide — not a reproduction of the manufacturer's manual — and ManualHarbor is not affiliated with Goodman. Always follow the safety instructions, installation requirements and warranty terms supplied with your unit, and contact Goodman or an authorized service provider for warranty repairs and replacement parts.
Running-cost figures use assumed U.S. average utility prices and are estimates for comparison only. See our editorial methodology for details.
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