Why does the same drain keep clogging?
Getting water moving again doesn't necessarily explain why a drain blocked. If the same problem keeps returning, ask what the earlier clearing visits found and whether the next visit will investigate the cause.
Buildup, roots and pipe damage are among the conditions described in drain inspection guidance. That list can't tell you which one is in your pipe.
Tell the shop what's backing up
Describe the fixtures involved: one sink, one toilet or several drains. Mention water appearing at another fixture and how soon the blockage returned after the last service.
Give the shop earlier invoices or inspection reports. Don't call everything “the main line” unless that location has been confirmed. Don't run more water just to recreate a backup for a video.
What would a camera inspection add?
A camera can help a contractor inspect an accessible pipe and explain a recurring blockage or suspected damage. Ask which section they will inspect, how they will reach it and whether you receive the recording and an explanation.
The location matters. A close up image is more useful when the contractor can show where it came from, what it shows and how it relates to the proposed repair.
An inspection also has limits. Ask about any part the contractor couldn't reach or see clearly. Not every clog needs a camera, and paying for one doesn't automatically mean pipe replacement is the next step.
Separate the three possible charges
Clearing: Work to restore flow.
Inspection: Work to investigate the pipe and report what was found.
Repair: Work to address a particular defect or condition.
Ask which services the price includes and how further work would be approved. If replacement is recommended, get the location, length, access work and restoration described before comparing quotes.
Mention a backup into the house immediately
Tell the shop if sewage may be entering a tub, shower or floor drain. That needs a different response from an ordinary slow sink. Seek appropriate emergency or health guidance for immediate safety concerns.
Also say if the property uses septic. EPA's septic guidance describes problems requiring a system specific investigation. A septic system and a connection to a public sewer aren't interchangeable service requests.
For a proposed repair farther along the line, see the sewer responsibility guide.
Sources
- RIDGID’s drain diagnostic guidance: www.ridgid.com/us/en/diagnostics-drain-cleaning-promo
- septic malfunction guidance: www.epa.gov/septic/resolving-septic-system-malfunctions