Frequently asked questions

Once a year under NFPA 211, the national chimney and fireplace standard. That applies even to fireplaces you rarely use.

A Level 1 checks the readily accessible parts of the chimney and fireplace. A Level 2 adds a camera scan inside the flue and checks accessible attics and crawl spaces, and is recommended for home sales, appliance or fuel changes, relining, and after a fire or earthquake.

The residue left when wood smoke condenses on the inside of the flue. CSIA describes it as highly combustible; it can be flaky, sticky or a hard glaze.

They may help loosen deposits, but CSIA doesn't count them as a replacement for brushing and inspecting the flue.

Because that's when it rains. San Diego gets most of its rain from December to March, so a cracked crown, loose flashing or missing cap may go unnoticed until the first storms.

A cap keeps rain, birds, rodents and debris out of the flue and screens sparks. If your chimney doesn't have one, it's one of the simplest improvements you can make. See chimney caps.

Yes, after a Level 2 inspection to see what's happened inside the flue. Don't use the fireplace until it's been checked.

Usually a closed or broken damper, a restricted flue, a blocked cap, or not enough air reaching the fire. See fireplace repair.

Yes. The flue and vent can still be blocked by nests or debris. Burner and valve repairs are for a qualified gas technician.

Only with a reason behind it: mold you can see inside the system, rodents or insects, or registers that blow dust. Routine cleaning isn't something the EPA recommends.

All the components air passes through: supply and return ducts, registers and grilles, the blower and housing, and the air handler. Cleaning only part can recontaminate the rest.

No. The EPA doesn't certify duct cleaning companies, so be wary of anyone who claims it.

A clogged or crushed vent is a common cause. Hot, damp air can't escape, so clothes stay wet longer.

Yes. U.S. Fire Administration data lists failure to clean as the leading contributing factor in home dryer fires for 2018 to 2020.

Empty the lint screen at the start and end of every load, keep the floor behind the dryer clear, and watch that the outside flap lifts while it runs.