When does a clogged drain need a plumber instead of a plunger?

A plunger is the right first tool when one fixture is slow or stopped: a single sink, tub or toilet. It stops being the right tool once the clog is somewhere a plunger cannot push, such as a shared line, the main sewer line or a septic system, or once you have tried properly and nothing has moved. The signs are fairly clear, and spotting them early saves a mess.

Give the plunger a fair try

Most failed plunging is plunging done without a seal. In a double bowl sink, plug the other drain; in a single bowl sink or a tub, plug the overflow opening with a wet rag.^[1] Keep enough water in the fixture to cover the cup, then press the plunger down smoothly, jerk it up sharply, and repeat 20 to 30 times.^[1]

Use the right plunger for the fixture. A flat cup seals on a sink or tub floor. For toilets, Oatey's advice is plain: "A flange plunger is ideal for toilets because it creates a better seal." If the water in the bowl is rising, close the supply valve near the base of the toilet to prevent an overflow.^[2] Do not keep flushing a clogged toilet to test it.

On a sink, the trap is the next stop: most sink clogs are in the trap^[1], and clearing it takes a bucket and a few minutes. A hand snake for sinks and tubs, or a toilet auger for toilets, reaches a little further. The full method is in how to unclog a kitchen sink without chemicals.

If you have done all of that and the drain has not moved, a plumber with a powered drain machine is the next step, not a stronger chemical.

Signs the clog is past the plunger

Water rises in one fixture when you use another. That means the blockage is in a line two fixtures share, beyond their traps. Fairfax County's wastewater division says: "If the backup occurs only when facilities (such as toilet, tub, washer or sinks) are used, it is possible that you need a plumber."^[3]

Several drains are slow at once, or the lowest one backs up. The City of Salem notes: "Backups will enter through the lowest drains first."^[5] Water at a basement floor drain, or a ground-floor shower filling when the toilet is flushed, points to the main line. See why several drains clog at once.

Sewage backs up when nothing is running. Fairfax County explains: "If you have sewage backing up when you are not using any of your facilities, it is possible that there is a problem in the county main line."^[3] Check with neighbors. Salem's guidance is that if the problem is affecting multiple buildings, call the city's water department, and if it appears to be one building, a licensed plumber is recommended.^[5]

A chemical opener is already in the drain. In its guidance for sewer backups, Salem's water department warns: "Chemical drain cleaners are not likely to help and can cause additional damage."^[5] And do not use a plunger on a drain with chemical cleaner in it^[1], because the push can splash it back at you.

The same drain keeps clogging. A repeat clog means something keeps feeding it or the pipe itself is catching debris. Fairfax County lists the warning signs: "Signs that laterals may require repair include: Frequently clogged drains, odor of sewage, and basement backups during rain."^[4] More in why a drain keeps clogging.

You are on septic and drains are slow everywhere. A full or failing tank can show up as slow drains through the whole house. The Virginia Department of Health gives one reason for regular pumping as: "To prevent the discovery of a septic system failure by the experience of untreated sewage backing up into the house." VDH recommends that the average household septic system be inspected at least every three years by a septic service professional.^[6] If yours is overdue, call a septic service, not only a plumber.

What a plumber brings that a plunger does not

A plumber clears main line clogs with a powered drain machine, ideally through an outside cleanout. Fairfax County notes that most laterals can be cleaned by accessing the sanitary cleanout.^[4] For a line that keeps clogging, a camera shows the cause. Fairfax's guidance: "The best way to assess the condition of a lateral is by Closed Circuit Television Video (CCTV) examination".^[4]

If the camera finds a broken pipe, the job becomes a repair. In Fairfax County, a repair or replacement on private property needs a plumbing permit from the county, a plumber must be certified, licensed and bonded to make any repairs, and repairs are inspected by the county's Building Inspections Branch.^[4]

Hiring a licensed plumber

Virginia's plumbing contractor classification covers piping, fixtures and appurtenances for sanitary or storm drainage facilities, venting systems related to plumbing, and sewerage systems.^[7] Under Code of Virginia § 54.1-1100, the Board for Contractors requires a master tradesmen licence as a condition of licensure for plumbing contractors.^[8] Look the business up on DPOR's licence lookup before you book.^[9]

Ask for the price in writing before the work starts: the trip charge, labor, the clearing method and whether a camera inspection is included. The Board for Contractors reminds homeowners that "Virginia law requires all licensed contractors to provide a written contract for residential work", and as a rule of thumb suggests an initial deposit of no more than 10% of the total price or $1,000, whichever is less.^[10] What drives the price is covered in what a plumber charges to unclog a drain in Virginia.

Stop and call a pro if

• Water rises in one fixture when another drains.
• More than one drain is slow, or the lowest drain in the house backs up.
• Sewage appears at a floor drain, tub or toilet.
• A chemical opener is sitting in the drain.
• The plunger, the trap and a hand snake have all failed.
• The same drain has clogged more than once in a few months.

You can also browse plumbing repair answers or look up plumbers in Blacksburg.

Past the plunger? Describe the clog once and licensed local plumbers quote it.