An Introduction

Our Blog series Water Heaters: Back to Basics will be a four part series discussing just the basics of Water Heater components, functions of components, and some top troubleshooting tips. Our goal in this blog series is to inform some of our core audiences – service techs and distributors – so that whether it is a house call to service or making sure the customer gets the repair parts that are right for the job, we want to help our readers improve business, customer satisfaction, and profits through the education we offer.

Written by

Kevin Parham

Published Date

June 16, 2017

Part 1

Water Heater Components: Gas & Electric Overview

Both Gas and Electric storage type Water Heaters have many common components. Let’s briefly review them and what they do.

1. Cold Water Shut Off Valve – a must for future maintenance so that you don’t have to cut off water to the entire house. These valves are usually ball valve, but you might see older installs with gate valves like those on a water hose bib. You want to upgrade to a ball valve for more reliability as gate valves can rust into place over time preventing the handle from turning. Our friends at Eastman EZ Flow have great products for this such as the PUSH-FIT BALL VALVE 48232

2. Temperature & Pressure Relief Valve – commonly called the T&P comes pre-installed on all water heaters, this is a required safety device. DO NOT REMOVE OR SEAL CLOSED. Pipe to drain with Overflow Pipe. If T&P leaks or drips regularly or water damage evidence is at bottom of heater, either 1) install expansion tank to relieve pressure, or 2) check if expansion tank is pressurized to match water pressure, or 3) replace T&P. Watch a helpful video from here or link this Technical Bulletin 45 from State Water Heaters.

3. Overflow Pipe – see Temperature & Pressure Relief Valve section above.

4. Hot Water Outlet – this is where the hot water leaves the water heater to deliver hot water to all the fixtures: shower, sinks, etc. Insulate this pipe at every inch of pipe possible. Many older homes do not have insulation here. This is the biggest reason you have to ‘wait for the shower to get hot’. Proper insulation saves water and energy. Check local codes, usually ½”, ¾”, or 1”. Our insulation partners at NOMACO have the options. 

Expansion Tanks installed at Cold Water can greatly extend the life of a Water Heater

5. Anti-corrosion Anode Rod – aluminum, magnesium, or zinc rods with a steel wire core. Sacrifices itself to protect the steel inside of water heater. Meant to replace every 3 month to 1 year. We will discuss more is Part Four.

6. Dip Tube – used to transport supply water to the bottom of the tank to actively mix or stir the water inside the tank. This helps prevent natural minerals (or sediment) from settling at the bottom of the water heater tank. See Drain Valves section below for more detail.

7. Insulation – effects efficiency by minimizing heat loss from the storage of hot water. Installed at the factory, you may only see the insulation while changing the anode rod or the elements found in an electric heater. New NAECA III energy requirements required thicker insulation in April 2015 causing some newer ware heaters to be wider. This has caused a rise in demand for tankless replacements since the some of the new heaters are too large to fit in the same space as the old heater

8. Drain Valves – positioned at the bottom of the heater, these work as advertise – they drain the tank. It is recommended to drain your tank once a year. If you wait too long, sediment may block the valve preventing drainage. Overtime, failing to drain a water heater will affect performance up to half the hot water output. We will discuss more is Part Four.

Next week in Part Two we will be talking Electric & Gas Water Heaters. Electric: Thermostats and Elements & Gas: Flue/Gas: Draft Hood

For General Water Heater Maintenance tips, visit our partners at – watch this video