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TelephonesCorded Phone

AT&T CL84118 Telephone Manual

Setup, everyday use, maintenance and troubleshooting for the corded phone, with verified specifications.

  • TypeCorded Phone
  • LineAnalog phone line
  • Standby power0.55 W
  • Est. yearly cost$0.82

About the AT&T CL84118

AT&T model CL84118 is a corded phone that meets ENERGY STAR telephony requirements. The certification also covers related models such as CL84318.

It works on a standard analog phone line. The base is powered by an external AC adapter.

Measured standby power is 0.55 W — about 4.82 kWh or $0.82 a year if it stays plugged in around the clock, as phones normally do. That is lower than 81% of the 37 telephone models in our database.

Specifications

BrandAT&T
Model numberCL84118
Phone typeCorded Phone
Line technologyAnalog
ConfigurationCorded
External power adapterIncluded
Standby (idle) power0.55 W

Safety information

  • Use only the power adapter supplied with the phone or exact replacements from the manufacturer.
  • Do not use the phone near water — for example near a bathtub, sink or swimming pool — and never handle it with wet hands.
  • Avoid using a corded telephone during an electrical storm; there is a small risk of electric shock from lightning carried on the phone line.
  • Do not use the phone to report a gas leak while you are near the leak. Leave the area first.
  • Features powered by the AC adapter (such as the display, speakerphone or any cordless handsets) stop working in a power outage. Keep a mobile phone available for emergencies.

Setup

  1. Choose a location

    Place the base near a phone jack and AC outlet.

  2. Connect the phone line

    Connect the telephone line cord from the base to the wall jack. If you have DSL internet on the same line, install a DSL filter between the jack and the phone to prevent noise.

  3. Connect power

    Plug the AC adapter into the base and into an outlet not controlled by a wall switch.

  4. Install and charge handset batteries

    If the model includes cordless handsets, install the battery packs and charge them fully in the base or chargers before first use, following the time given in the manual.

  5. Set date, time and options

    Set the date and time, ringer volume and language. If the model has an answering system or caller ID, configure them from the menu and record your greeting.

Using your phone

Calls and audio

  • Adjust the earpiece or speaker volume during a call with the volume keys; the setting is usually remembered for the next call.

Power use

Phones stay powered all the time, so standby power is what matters. This model draws 0.55 W when idle.

Care and maintenance

WhenWhat to do
WeeklyWipe the handset, keypad and display with a soft cloth lightly dampened with water or a mild disinfectant wipe; do not spray liquids directly on the phone or use solvents.
Every 6 monthsCheck cords and plugs for damage.

Troubleshooting

Try these steps before calling for service. For model-specific error messages, consult the manufacturer's manual or your phone system administrator.

ProblemPossible causeWhat to try
No dial toneLine cord loose or damaged; phone service issue; base not powered.Reseat the line cord at both ends, check the adapter, and test the wall jack with another phone. If no phone works on the jack, contact your phone company.
Static or buzzing on callsDSL interference; damaged line or handset cord; nearby electrical equipment.Install a DSL filter, replace the line or handset cord, and move the phone away from power adapters and other electronics.
Display or keys unresponsiveTemporary software fault.Restart the phone by disconnecting power (or removing the handset battery) for 30 seconds.

Energy use and running costs

The AT&T CL84118 draws 0.55 W in standby — the idle state it spends nearly all of its time in. Plugged in 24 hours a day, 365 days a year, that is about 4.82 kWh per year, or $0.82 at $0.17 per kWh.

Talk time adds very little energy compared with standby, because calls are short relative to the hours the phone sits idle.

Frequently asked questions

What kind of phone is the AT&T CL84118?

It is a corded phone for analog landline service.

How much electricity does the AT&T CL84118 use?

It draws 0.55 W in standby, about 4.82 kWh per year — roughly $0.82 at $0.17/kWh if left on continuously.

Will the AT&T CL84118 work during a power outage?

Features that rely on the AC adapter stop working in an outage. Whether basic calls still work on line power depends on the model, so check the manual and keep a mobile phone available.

Is the AT&T CL84118 ENERGY STAR certified?

Yes. It is on the ENERGY STAR certified telephony list, with a certification date of March 2025.

Sources and disclaimer

Specifications on this page come from the ENERGY STAR certified telephones dataset published by the U.S. Environmental Protection Agency (record certified March 4, 2025), 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 AT&T. Always follow the safety instructions, installation requirements and warranty terms supplied with your unit, and contact AT&T 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.