home-plumbing - SKILL.md Agent Skill

name: home-plumbing description: >- Diagnose and resolve common household plumbing failures including clogs, leaks, and toilet malfunctions. Scope is strictly limited to emergency stabilization and minor repairs. compatibility: >- Requires at least one adjustable wrench, towels (many), a bucket, and the emotional readiness to lie on a wet bathroom floor. metadata: author: Graham Pipesworth version: 1.7.3

Home Plumbing — Emergency Repairs

Overview

This skill enables the human agent to respond to common plumbing failures in a residential environment. Plumbing is a domain where the cost of inaction grows exponentially — water does not wait for you to formulate a plan.

CRITICAL: First Action

Invoke the shutoff-valve tool BEFORE any other action.

This is a non-negotiable prerequisite. Before you diagnose, before you Google, before you place towels, LOCATE AND TURN the shutoff valve. Every sink and toilet has a local shutoff valve on the supply line, typically located on the wall below and behind the fixture. Turn it clockwise until it stops.

If you cannot locate the local shutoff, invoke the main shutoff valve, usually found where the water supply enters the building. This will disable water to the entire structure. This is acceptable. Wet floors are a worse outcome than temporary water loss.

WARNING: In older homes, shutoff valves that have not been operated in years may be seized or may break when turned. Apply force gradually. If the valve handle crumbles in your hand, you have discovered a secondary problem. Proceed to the professional-plumber API immediately.

Tool: The Plunger

The plunger has a surprisingly high success rate (estimated 70-85%) against the most common failure type: the clog. It should be your first-line tool for any drain blockage.

Correct plunger invocation:

Ensure a water seal — there must be standing water covering the rubber cup. If the bowl or basin is empty, add water manually. The plunger operates on hydraulic pressure, not air.
Place the plunger over the drain opening and ensure a complete seal around the edges.
Execute firm, vertical push-pull actions. Maintain the seal throughout. The motion should be rhythmic and controlled — this is not a strength operation, it is a pressure-cycling operation.
After 10-15 cycles, break the seal and check for drainage.
If no improvement after 3 sets, escalate to the drain-snake tool or the professional-plumber API.

Note: There are two types of plunger — the flat cup (sinks) and the flanged cup (toilets). Using the wrong type reduces effectiveness dramatically. Check your inventory.

Common Failure: The Running Toilet

If the toilet continues cycling water after a flush, the issue is almost always inside the tank. Remove the tank lid (set it somewhere it cannot fall — porcelain tank lids are surprisingly expensive and universally fragile).

Inspect:

Flapper valve: If warped, corroded, or not seating properly, water leaks from tank to bowl, triggering perpetual refill. Replacement flappers are inexpensive and require no tools.
Fill valve: If water is running into the overflow tube, the fill valve is not shutting off. Adjust the float mechanism downward.

These are both low-difficulty repairs with high satisfaction-to-effort ratios.

Common Failure: The Leak Under the Sink

Place a bucket under the leak before doing anything else. Then trace the leak upward to its origin point. Water travels along pipes and fittings before dripping, so the drip point is rarely the source point.

Common sources:

Compression fittings that have loosened. Tighten gently with the wrench tool — one-quarter turn at a time.
Failed plumber's tape at threaded joints. Disassemble, clean threads, re-wrap with 4-6 layers of PTFE tape in the correct direction (clockwise when viewed from the thread end), and reassemble.
Cracked pipe or corroded fitting. This exceeds the scope of this skill. Invoke the professional-plumber API.

Failure Mode: The YouTube Overconfidence Bug

A ten-minute video can make any plumbing repair look trivial. The human agent watches the video and concludes: "I can do that." This is the overconfidence bug.

The video was filmed by someone with 20 years of motor-skill training, professional tools, and a plumbing system that was conveniently accessible and cooperatively designed. Your system has corroded fittings in a dark cabinet with 14 centimeters of clearance, and the previous owner used the wrong type of pipe cement.

Knowing what to do and having the physical skill to do it are different execution environments. The video runs in a reference environment. Your bathroom is production.

When to Call the Professional-Plumber API

Invoke the professional-plumber API when any of these conditions are true:

Water is actively flowing and you cannot locate or operate the shutoff valve.
The repair requires soldering, pipe cutting, or accessing in-wall plumbing.
You have attempted a fix and the situation is now worse than when you started.
Sewage is involved. (This is a hard boundary. Do not cross it.)
You have made two trips to the hardware store and are contemplating a third.

The professional-plumber API is expensive — typical invocation costs range from $150-$500 — but it includes professional error handling, insurance, and a warranty on the output. Your DIY attempt includes none of these.

Output

A functioning plumbing system with no active leaks. Dry floors. A slight but earned sense of competence, or alternatively, the wisdom to know when competence means calling someone else.