The Plumbing Walk Every Listing Should Get First

At the water heater

This is where the most negotiation value sits, because it is the item buyers price most aggressively. Read the label, look at the base, and look up at the vent.

• Manufacture date from the serial label — note it, do not guess
• Rust or moisture at the base of the tank
• A relief valve with no discharge pipe, or one terminating improperly
• Corrosion or weeping at the top fittings
• Vent connector slope and condition on gas units

Under every sink

Two minutes per cabinet catches the items inspectors list one after another. Run the faucet while you look.

• Active drips at supply stops and trap joints
• Staining or swollen cabinet floors from past leaks
• Corroded or seized shutoff valves
• Improvised repairs: tape, putty, flexible corrugated drain runs

At every fixture

Run each fixture long enough to see drainage behavior, not just flow. A drain that backs up after thirty seconds looks fine in a five-second test.

• Slow drains, especially in more than one fixture
• Toilets that rock, run continuously or refill slowly
• Weak hot water pressure at a single fixture
• Tub and shower diverters that will not hold

In the basement or crawl

This is where the expensive findings live, and where sellers most often have never looked.

• Visible piping material: galvanized, polybutylene or mixed materials
• Efflorescence, staining or corrosion on and around lines
• Main shutoff location, accessibility and whether it actually turns
• Sump pump present, plugged in and functional if the home has one
• Signs of prior water at the floor perimeter

Decide what to fix before listing

Fix the cheap safety items and anything actively leaking — they cost little and remove obvious leverage. For big-ticket items like an aging water heater, get a written condition assessment instead of pre-emptively replacing it. A documented working unit defends the price better than a concession does.

• Fix now: active leaks, missing T&P discharge, running toilets, seized stops
• Assess and document: water heater condition, older piping, drain performance
• Disclose per your jurisdiction's requirements — never conceal a known defect

Between contract and closing

Once an inspection report lands, speed and paperwork are everything. Send the plumbing pages, get a scope tied to each line item, and make sure the invoice describes the specific correction rather than a generic service line.