How far should a horizontal drain pipe slope for proper drainage?

A horizontal drain line should generally slope downward 1/4 inch per foot toward the drain.

What must be removed before connecting a dishwasher to a new garbage disposal?

Remove the dishwasher knockout plug inside the disposal inlet; otherwise, the dishwasher will not drain.

Which way should PTFE (Teflon) tape be wrapped on plumbing threads?

Wrap it clockwise, following the direction the fitting tightens, using smooth overlapping turns.

Free Course Image Plumbing for Homeowners

Free online course Plumbing for Homeowners

Duration of the online course: 2 hours and 12 minutes

4.5

(2)

Fix leaks and upgrade your home plumbing with a free online course—learn PEX, toilets, faucets, drains, and water-heater care with practical, confidence-building lessons.

In this free course, learn about

PEX Pipe Basics
Toilet and Kitchen Fixture Installation
Drainage Principles and Water Heater Basics
Practical Plumbing Troubleshooting
Thread Sealing and Plumbing Hand Tools
Toilet Leak Diagnosis and Water Heater Longevity

About the free online course

Plumbing problems have a way of showing up at the worst possible moment: a rocking toilet that suddenly leaks, a garbage disposal that starts clanking, a slow drain that turns into a full backup, or a water heater that smells like sulfur and never seems to last as long as it should. This free online course helps homeowners build practical, job-ready plumbing skills so you can handle common repairs safely, spot trouble early, and avoid costly mistakes that turn small issues into major damage.

You’ll learn how modern plumbing materials work in real homes, including how to make reliable PEX connections, position clamp rings correctly, and choose techniques that reduce the risk of future leaks. The course also walks through high-impact fixture projects many homeowners want to tackle: installing a new toilet, replacing a kitchen faucet, and swapping a garbage disposal while ensuring proper draining connections. Along the way, you’ll sharpen your troubleshooting instincts by understanding why drains fail, how P-traps protect your home, and what safe first steps to take before reaching for harsh chemicals or expensive service calls.

Water heaters get special attention because they are one of the most expensive and failure-prone systems in the house. You’ll learn sensible temperature settings, what extends tank life, how to address odors and sediment, and which upgrades can reduce corrosion and maintenance over time. The course also focuses on hands-on fundamentals that make every repair more dependable, such as using pipe wrenches and pliers correctly, removing stuck threaded parts without ruining threads, and applying PTFE/Teflon tape the right way to prevent drips and callbacks.

With quick explanations, practical demonstrations, and targeted exercises, you’ll finish with the confidence to plan repairs, work cleanly, and make decisions that protect your plumbing system for the long term. Whether you’re maintaining your own home or exploring construction and professional skills, this course helps you turn everyday plumbing tasks into reliable results.

Course content

Video class: PEX Pipe: Plumbing for Homeowners 12m
Exercise: Proper placement of clamp rings on PEX pipe

Video class: How to Install a New Toilet 09m
Exercise: What is the correct sequence to remove water from a toilet before removal?
Video class: How to Replace a Garbage Disposal - Easy, Step-by-Step 11m
Exercise: Before connecting a dishwasher to a new garbage disposal, what must you do to ensure proper draining?
Video class: How to Replace a Kitchen Faucet in 30 Minutes 09m
Exercise: Where should you place the pull-down hose weight when installing a kitchen faucet?

Video class: How Do P-Traps Work? 5 Drain Issues to Watch Out For 06m
Exercise: What is the recommended slope for a horizontal drain line to ensure proper drainage
Video class: 5 Things You Should Know About Your Water Heater! 03m
Exercise: What is the recommended default hot water temperature setting for most homes on a gas water heater?

Video class: 5 Clever Plumbing Tricks to Save You Money 10m
Exercise: What should you try first when a garbage disposal makes loud metal clanking?
Video class: Replace Your Water Heater Yourself in 10 Easy Steps 08m
Exercise: Correct way to apply Teflon tape to water heater connections
Video class: One Simple Trick For Unclogging Your Drain 02m
Exercise: What is the best first step to clear a slow tub or sink drain safely and quickly

Video class: 6 Plumbing Mistakes DIYers Make with Teflon Tape 10m
Exercise: Best practice for applying PTFE thread seal tape on plumbing threads
Video class: The Clever Tool Most People Have Never Heard Of 03m
Exercise: Safely removing a stuck threaded nipple without damaging threads
Video class: 3 MISTAKES We Make Using Pipe Wrenches 06m
Exercise: Proper Use of Pipe Wrenches and Tongue-and-Groove Pliers

Video class: These Came Loose 08m
Exercise: What is the most likely cause of a ceiling leak that appears only after flushing when the upstairs toilet rocks slightly?
Video class: 30 Minute Secret Makes Your Water Heater Last Decades 13m
Exercise: What is the most effective upgrade to maximize a tank water heater’s lifespan while eliminating sulfur smell?
Video class: One Simple Trick That Doubles Your Water Heater's Life 14m
Exercise: Which upgrade best reduces corrosion, sulfur smell, and sediment in a tank style water heater while lowering maintenance needs?

Learn aboutPlumbing

Explore free online plumbing courses designed to help beginners and professionals build practical skills in pipework, water systems, repairs, installation, maintenance, and safety. Learn at your own pace, improve your career prospects, and earn a certificate upon completion with flexible plumbing training available online.