Skip to main content

Drain the Water Heater — Drain the Water Heater Partially

Beginner3 hours

Part of project

How to Replace a Water Heater's T&P Relief Valve · Step 2 of 8

Helpful?

In this video

Attach a garden hose to the drain valve located at the bottom of the water heater tank. Run the other end of the hose to a floor drain or outside. Open the drain valve, which may require a flathead screwdriver. To accelerate the draining process, open the Temperature and Pressure (T&P) relief valve on top of the tank to allow air to enter and break the vacuum. For even faster draining, a transfer pump can be connected to the hose.

Goal: Empty Water Heater Tank

  • Opening a hot water faucet in a nearby sink or tub can also help introduce air into the system and speed up the draining process.

Used in this video

  • Garden Hose (Tool Type: Garden Hose Length)Directing water from the drain valve to a safe drainage area.
  • Flathead Screwdriver (Tool Type: Screwdriver, Screwdriver Type: Flathead)Turning the slot on the drain valve to open it.
  • Transfer Pump (Power Source: Electric) · optionalActively pumping water out of the tank to significantly speed up the draining process.
8.0K views4630-90 minutes
RepairClinic.com

662K subscribers

View Channel

FAQs

Is replacing a T&P relief valve a safe DIY project for a beginner, or should I call a professional?

This is a beginner-level plumbing task, but only if you strictly follow all safety procedures, especially shutting off power/gas and water completely. If you are uncomfortable working with basic plumbing, or especially electrical/gas connections, it's always safer to consult a qualified professional. Your safety is paramount.

Do I really need specialized pipe wrenches, or can I get by with regular adjustable wrenches for this job?

While it might be tempting to use adjustable wrenches, specialized pipe wrenches (like the 12-inch or 16-inch options listed) are highly recommended. They provide a much stronger, non-slip grip on rounded pipes and fittings, which is crucial for loosening a potentially corroded old T&P valve without damaging the water heater connections. This prevents frustration and potential leaks.

What's the most common mistake people make when replacing a T&P valve, and how can I avoid it?

The most common mistake is not properly sealing the new valve's threads, which leads to leaks after refilling the tank. To avoid this, always apply 3-5 layers of Teflon tape (clockwise) to the threads of the new T&P valve before screwing it into the tank. Also, ensure the discharge pipe is snug but not overtightened, especially if it's plastic, to prevent stripping.

How much time should I realistically set aside for this project, and what's the typical cost for parts?

While estimated at 3 hours, it's wise to set aside a half-day (4-5 hours) for this project to account for unexpected challenges like stubborn old valves or thorough draining/refilling. The primary cost is the new T&P valve itself, which usually ranges from $15-$30, plus a few dollars for Teflon tape and rags if you don't already have them.

Drain the Water Heater — How to Replace a Water Heater's T&P Relief Valve (Step 2, Video 2) | Stesso