Click Here To Read Part 1 (of 2): Water Heater Installation Texas Code Part 1 (of 2)

This is Part-2 (of 2) about Water Heater Codes For Installation.   Al’s Plumbing, Heating & A/C in Plano, Texas offers full-service plumbing; maintenance, repairs, and replacements for every plumbing component in your home.  Al’s sells and installs gas & electric water heaters.  Al’s is near your home in Plano, Garland, and Richardson.  We service all homes in northeastern Dallas County, TX, and southern Denton County, TX with no additional travel charges.

Al’s also provides maintenance & repairs for all brands of; Central A/C, Gas & Electric Furnace, and Heat Pumps.  Additionally, we sell and install new HVAC Systems from American Standard (same company as Trane), Ameristar, and Coleman HVAC (same company as York HVAC).

Call Al’s today to discuss any concerns or problems you have with your HVAC System or Plumbing.

We’ll arrange an appointment at your convenience.

Water Heater Installation Codes — General Information

For TEXAS’ Specific Water Heater Installation Codes

Copy The Link Below Into Your Browser:

water heater being serviced

Image Source: ShutterStock

2021 International Residential Code (IRC) Requirements For Water Heater Installation

This article describes water heater codes for installation in general terms -AND- provides a link for Texas’ specific codes.   The International Building Code (IBC) is adopted (or in use to some extent) by all 50 states.   With continuing advances in  building-materials & building-sciences — Building Codes continue to evolve and be updated.

The International Building Code (IBC) is updated every 3 years.  When this article was written — The Current IBC was the 2021 edition (known as ICC IBC-2021).  The IBC is a comprehensive code that comprises all; building, plumbing, mechanical, fuel, gas, and electrical codes requirements. 

Image Source: Embedded Link

SHOWN: 2021 International Building Code Manual

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For TEXAS’ Specific Water Heater Installation Codes,

Copy The Link Below Into Your Browser:

Components Used In Water Heater Installation

NOTE: The descriptions below are for General Information.  Use the link provided above for Specific TEXAS water heater codes.

GAS Water Heater Exhaust Venting

  • Double-Wall (Type B) Metal Exhaust Vent Pipe.

Image Source: Embedded Link

SHOWN: Double-Wall Vent Pipe

Gas water heaters must be vented with double-wall, metal exhaust pipe.   The inner wall contains the exhaust.  The outer wall remains cooler — because of the air gap between the walls.  This is necessary to ensure the exhaust pipe doesn’t get hot enough to set nearby building materials on fire.

Codes for How Far The Exhaust Pipe Must Rise above the roof vary by municipality.  It’s often 5 feet between the water heater’s vent hood (at the top of the water heater) —  to where the exhaust pipes’ vent cap is located above the roof.

Water Pipe Insulation

Code typically requires the first 5 feet of hot & cold water pipes to be insulated if exposed in unconditioned space (like attic or garage).

Image Source: Embedded Link

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SHOWN: Foam Water Pipe Insulation


These Codes protect from electrocution-risk — while working on an electric water heater.

For electric waters — The National Electric Code (NEC) allows the Circuit Breaker to be the disconnection for (permanently connected) appliances — that use less than 300 amps.  In a typical home, this includes; (electric) water heater, (electric) furnace, and Central A/C.  A typical electric residential water heater uses around 19 amps (details below),

Note: Local codes may vary.

A; typical, residential, electric, water heater uses around 4,500 watts.

WATTS divided by VOLTS = AMPs

4,500 (watts) Divided By 240 (volts) = 18.75 Amps

This requires only a Circuit Breaker to disconnect power from the water heater.

photo of circuit breaker panel

Image Source: CanStockPhoto

Additional Electric Water Heater Codes Requirements (if applies)

2. Water Heater Code requires an electric water heater — Must Have A Disconnect Near The Water Heater.


  • The Circuit Breaker can be seen from the water heater  — within 50 feet, with an unobstructed view.


  • There is a Locking Device on the circuit breaker — Only if the Circuit Breaker can’t be seen from the water heater.

NOTE:  A Lockout Device never interferes with a circuit breaker’s operation.  When a circuit breaker trips, power is shut off regardless of whether the breaker’s handle can move or not.

Image Source: Embedded Video

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Shown: Circuit Breaker Lock-Out Device

Temperature & Pressure (T&P) Relief Valve (ALL Water Heaters)

Water heater code requires a Temperature & Pressure (T&P) Relieve Valve Be Installed.   To prevent a water heater explosion — in the event the water heater malfunctions (and doesn’t stop heating) — the T & P Valve will open at a Predetermined Pressure (around 150 Pounds Per Square Inch (PSI) and/or a Predetermined Temperature (around 210F).

The valve allows overly pressurized and/or overly hot water to escape from the tank (to prevent it from exploding) — until the pressure and/or temperature drops below the valve’s pre-set levels.  Then the valve recloses.

photo of water heater

Shown: T&P Discharge Pipe Runs From The Valve To The Side Of The Water Heater And Downward

Water Heater Code Requires:

  • A Discharge Pipe serving a T & P valve shall be 1 size larger than the T&P valve’s outlet.
  • The outlet end of the discharge pipe must be fastened in place.

WHY?:  Without the discharge pipe in place — if T&P Valve opens, scalding hot water would exit the valve horizontally.  The water can move in all directions from near the top of the water heater.

  • This pipe is to ensure scalding water discharges near the floor — and to a nearby drain.
  • If no drain is nearby — a drainage pan must be installed (under the water heater) and connected to a drain line to an indoor drain or to outdoors.

Drainage Pan Under The Water Heater

It’s not uncommon for DFW homes to have a water heater(s) in their attic.  If a water heater is located where it can cause water damage (Examples: attic, 2nd floor, water heater closet) — it must have a drainage pan underneath it.  This very hot water must be safely captured and routed into a drain, or to outdoors.

  • When their water heater tank cracks — most water heaters have a steady flow of hot water coming out.
  • A drainage pan must be at least 1-1/2 inches deep.
  • An ELECTRIC water heater’s discharge pan can be plastic or aluminum.
  • A GAS water heater discharge pan must be Aluminum (doesn’t rust) OR galvanized Steel — with a thickness of .0236 inch or more.
  • Galvanizing coats steel to helps prevent rusting.

Image Source: Embedded Link

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SHOWN: 24″ Aluminum Water Heater Pan — Click On Link For Additional Sizes.

Thermal-Expansion Tank 

photo of water heater with expansion tank shown

Image Source: ShutterStock

Shown: Thermal Expansion Tank For Water Heater

Water Heater Code may require a Thermal Expansion Tank be installed.  While a good ideal in every setting — it’s even more important when the cold water line (going to the water heater) is equipped with a:

  • Check Valve
  • Pressure-Reducing Valve
  • Backflow-Preventer.

Any of these will not allow expanded water (water expands when heated) to move backward into the cold water line.

It’s estimated that 50 gallons of cold water expands to 52 gallons when heated to 120°F.  When that 2 gallons of water can’t go backward into the cold water supply line (because one of the valves above prevent that) — pressure inside the water heater increases.

120F degrees is the safety recommendation to prevent scalding — though 140° is a common preferred thermostat setting.  Below 120F degrees — there’s a risk that bacteria might develop inside a water heater.

  • The water heater creates extra water-volume each time it heats.
  • A water heater Thermal Expansion Tank provides a place for excess water to go.
  • The extra water volume can create excess pressure within the plumbing.
  • This could possibly cause damage to the water heater and/or water pipes.
  • When thermally-expanded water is present:
  • Turn a hot water faucet, and it may briefly dispense hot water at a noticeably higher pressure — and then return to normal pressure.
  • This can lead to splashing of hot water.

How A Thermal Expansion Tank Works

  • When the water heater is heating — the added water volume moves into the thermal expansion tank.
  • When the water (inside the water heater) cools — the thermal expansion tank returns the water to the water heater.

Water Shut-Off Valve

(this shutoff is located where cold water enters the water heater)

photo of water heater

Image Source: CanStockPhoto

Shown: Water Heater Installation With Shut Off Valve For Both Cold & Hot Water Lines

Water Heater Code requires a separate shut-off for the cold water supply to a water heater.  This shut-off allows water to be turned off to only the water heater — while the rest of the house continues to receive cold water.

Shut Off Valve TYPE


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Shown: Ball-Valve Style Water Shut-Off Valve.  Ball-Valves always have a lever handle.

Code requires and gate style valves (they have round handles) be replaced with Gate Valves.

WHY?  Gate-style water valves are more prone to failure.  Failed gate valves won’t shut off completely, or shut off at all.  See details below.

  • When closing a gate water valve, the shut-off device moves downward as the valve is turned off.
  • It’s common for debris to get in the way — sometimes resulting in the valve’s inability to close completely.
  • Its inside parts are brass.  Over time, corrosion occurs — and can “freeze” the valve in the open position.
  • Ball valves have a plastic or stainless-steel ball with a hole in the center (water flows through the hole).
  • Debris does not have a place to settle.
  • Because the ball is plastic or stainless-steel — corrosion is limited (if any).
  • These make ball valves more long-lasting and reliable.
  • With a ball valve — you can easily see if the valve is open or closed.  If the handle aligns with the pipes — the valve is open.
  • The stem (what the shut-off lever is attached to) is sealed by a rubber O-Ring under a nut.
  • For these reasons, ball valves are notably less prone to failure than gate valve

NOTE: This Is Part 2 Of A 2-Part Article:  Click Below To Read Part 1: Water Heater Installation Texas Code Part 1 (of 2)

Side Note #1

Electrical Bonding/Grounding Of Copper Water Pipes (at the water heater). 

Code always requires grounding of the cold water line where it enters the house.  Additionally, some Codes require Bonding Of The Hot & Cold Water Lines At The Water Heater.   Even if the local Code doesn’t require Bonding — it can reduce or eliminate damage to the home as a result of a Lightning Strike.  We explain how Bonding at the water heater works just below.

We use Bonding/Grounding together — because Bonding & Grounding work together to carry electrical-energy (like a direct or nearby lightning strike) away from metals never intended (nor designed to) carry electrical-energy.

Examples: Water pipes and Corrugated Stainless Steel Tubing (CSST) — it’s the flexible gas pipe used in most newer homes.

  • Bonding is connecting assorted metal components (not intended to carry electrical energy) to each other.
  • This allows electrical energy to find a path away from these components.
  • Grounding is the attachment of a bonded system(s) to the earth — typically through the Electrical System’s Grounding Rod.
  • This provides electrical-energy a harmless location to go.

BENEFIT: At The Water Heater –Bonding/Grounding Prevents Corrosion Wherever Two (different) Metals Touch.

Click This Link To See A Photo Of What We’ve Just Described:

Corrosion Between (Copper) Water Pipe & (Steel) Connectors From Water Heater

  • Grounding the cold water pipe (as required by code) — protects only the cold water line.
  • The water heater creates a break between cold & hot water pipes.
  • An additional safeguard is bonding/grounding the hot & cold water pipes together (at the water heater).

BENEFIT: Helps Ensure The Entire Plumbing System Is Electrically Grounded.


  • Metal water pipes can carry electrical-energy (like from a lightning strike).
  • Grounding them gives the electrical-energy a path into the earth — and away from the pipes.    
  • This carries electrical-energy away from the home.
  • 6 AWG wire (or thicker) + clamps must be used to ground the water pipes.
  • Many Water Heater Codes require bonding/grounding of (copper) hot to cold water lines (entering the home).
  • Bonding/Grounding of a water heater isn’t required everywhere.

TIP:  It’s Worth Your While. The 2 Clamps + Wire cost about $15.oo — and it’s an easy DIY project.


The Video Below Shows What Bonding At The Water Heater Works & Looks

Image Source: Youtube Embedded Video

SHOWN: Cold & Hot Water Lines Bonded/Grounded To Each Other — At Time: 0:30/2:33

Side Note #2

Benefits Of PEX Flexible Water Lines

(When building a new home — or need to repipe an existing home).

PEX water pipe

Image Source: Shutterstock

SHOWN: PEX water lines being installed in the attic of a new home (in the southern U.S.).

NOTE: PEX Pipes aren’t grounded because they can’t conduct electricity.

  • PEX stands for: “Cross-Linked Polyethylene” tubing/piping.
  • PEX is common in homes built around the mid-1990’s and later.
  • A specially designed Crimp-Tool compresses the fittings — to create seals with PEX tubing.


copper water pipes connection

Image Source: Shutterstock

SHOWN: 3 Copper Water Pipes Joined Together With A Fitting Requiring 3 Soldered Connections.

PEX water lines with copper connections

Image Source: Shutterstock

SHOWN: 3 PEX Water Pipes Joined Together With A Brass Fitting.

  • PEX crimp fittings are made of Brass OR Poly-Alloy (a form of plastic).
  • Crimp fittings use Copper or Stainless Steel Crimp Rings.

PEX Benefits With Problems Caused By Corrosive Or Scale Build-Up Water

corroded copper water pipe

Image Source: Shutterstock

SHOWN: Failed Copper Water Pipe — Due To Corrosion

Water with a pH <6.5 is acidic — and is corrosive.

Water with pH >8.2 is alkaline — and causes minerals build-up inside pipes.

Acidic Water Is Corrosive:

  • Water corrosivity depends on; the water’s pH, electrical conductivity, oxygen concentration, and temperature.
  • Acidic (low pH) can be treated with a (Neutralizing) Filter containing limestone (to raise the water’s pH).
  • Like water softeners — Neutralizing Filters must be back-washed periodically to remove particles (from the water) they collect.

PEX With Acidic Water:

  • PEX tubing won’t corrode.
  • Poly-Alloy (a form of plastic) Fittings are corrosion-resistant.
  • Note: Metal Fittings have corrosion potential.
  • Stainless Steel Crimp Rings are corrosion-resistant.
  • Note: Copper Crimp Rings have corrosion potential.

lime build up inside water pipe

Image Source: Shutterstock

SHOWN: Lime Build Up Inside A Metal Water Pipe

Alkaline Water Causes Scale Build-Up:

  • As water flows over, then sinks into the earth — it picks up bits of minerals within the soil.
  • The top 2 minerals are calcium & magnesium — causing water to be alkaline.  They make water “hard”.
  • Calcium (lime) & magnesium create sediment build-up inside water pipes.   
  • Alkaline/Hard water can be treated with a water softener.
  • A water softener removes; magnesium & calcium (lime) —  and adds sodium (salt). 



PEX With Alkaline Water:

  • PEX is more resistant to lime & magnesium scale build-up.
  • A Water Softener further reduces scale build-up.
  • An Electric Descaler (described below) Removes “Hard Water” Scale Build-Up — and minimizes future build-up.

Additional PEX Benefits

PEX water pipe

Image Source: Shutterstock

SHOWN: Flexible PEX — allows it to bend up to 90-degrees.

  • PEX tubing is notably less expensive than copper.
  • In December 2021: 1/2″ PEX:       $. 30 per foot at Home Depot.
  • In December 2021: 1/2″ Copper:  $1.55 — $2.10 at Home Depot.
  • Notably Lower Installation costs — due to PEX’s easier installation.
  • PEX can be bent up to 90-degrees — allowing it to route around a home’s structural elements.
  • With rigid pipes (Copper, PVC, & CPVC) —  each direction change requires a fitting.

PEX — Everyday Performance Versus Copper:

  • Water moves though PEX more quietly than copper.
  • PEX is more resistant to bursting from freezing than copper (it’s not freeze-proof).
  • PEX doesn’t lose heat from hot water lines as quickly as copper.
  • Copper pipes lose up to 35 BTU’s of heat (per hour) — per 1 foot of pipe.
  • Because PEX is made of durable plastic — it loses heat more slowly.
  • PEX can also be connected to existing copper water pipes — using fittings approved for those connections.

Copy This Link Into Your Browser For More Information About PEX:

NOTE: Copy The Link Below Into Your Browser For An In-Depth Booklet About PEX:

PEX water lines with copper connections

Image Source: Shutterstock

Shown: PEX Water Lines (red=hot & blue=cold) With Brass Fittings.

Side Note #3

Electric Descalers

A Way To Reduce (Existing) Calcium/Lime & Magnesium Build-Up Inside Water Pipes & Water Heater


Minimize Future Scale Build-up.

NOTE: We share this information as a service to our readers.  We don’t have first-hand knowledge of Electric Descalers.

Image Source: Embedded Link

Click On Image To: View Product, See Details, Or Order From

SHOWN: YARNA Brand — Capacitive Electronic Water Descaler System

At the time this was written, this product had nearly 1,000 reviews on Amazon — with a score of 4.4 (out of 5) Stars

NOTE: Al’s Plumbing Doesn’t Sell Or Install Electric Descalers.  You Can Purchase The One Shown On Amazon (click on the photo).

  • Electric descalers don’t require a plumber to install them.
  • They’re placed on the incoming water line (from the city) beyond 6.5 feet from where the water line is grounded (you’ll see a clamp and a wire where the water line is grounded).

TIP: If the descaler’s closer than 6.5 feet to the ground wire — the ground takes the descaler’s electrical-energy away, and it won’t work.

  • How long (existing) scale removal takes depends on the amount of existing scale built up on the water pipes.
  • The website page (click on the photo to go to the page) says: “Up to 3 months before badly scaled pipes begin to show improvement.”
  • This System does not use salt or water.

Electric Descalers’ Technology has been around for a while.

They remove existing Calcium & Magnesium build-up -AND- minimize new scale formation.

They Don’t Remove Calcium Or Magnesium From Incoming Water.  That Requires A Water Softener.


  • Unlike a Water Softener, an Electric Descaler Doesn’t Provide “Soft Water”.  That requires a water softener.
  • A descaler neutralizes the sharp edges on calcium & magnesium particles —  preventing them from sticking to surfaces.

One user states that with this specific Electric Descaler —  Calcium & Magnesium deposits (left behind after water dries) can be removed with a wet cloth.  That user stated it took CLR descaler and tremendous effort to remove deposits before the descaler was installed.

A user states they installed a Sediment Filter at the water heater– to catch the (existing) scale build-up that comes off the water heater.

Side Note #4

Bonding/Grounding Of Flexible, Corrugated Stainless Steel Tubing (CSST)

Used As GAS Lines — IS required by Building Codes everywhere.

corrugated stainless steel tubing CSST gas lines

Image Source:

SHOWN: Corrugated Stainless Steel Tubing (CSST) Flexible Gas Lines

  • CSST must be permanently bonded directly to the Grounding Electrode of the home’s electrical service.
  • Code does not allow CSST to be bonded to metal water pipes.


A ground rod is commonly located quite close to the electrical circuit breakers’ panel.  It’s typically made of copper or copper-coated steel. A rod is around ½” in diameter and 8 to 10 feet long.  It’s connected to the breakers’ panel to provide an approved ground connection.

If a grounding rod has a resistance of up to 25 ohms — building codes allow it to be the only grounding device.  If the rod’s resistance is greater than 25 ohms, at least 1 additional ground rod is required

The Purpose Of A Grounding Rod:

  • Reduces the chances of house fires caused by the electrical-energy caused by a (direct or nearby) lightning strike.


  • CSST gas pipes have a history of holes being created by lightning strikes.
  • Lightning strike electrical-energy can also ignite the escaping gas.


If Your Home Was Built Between 1988–2009

Its CSST Gas Lines May Not Be Bonded/Grounded.

Your Home & Safety Are At A Substantial Risk Of A Fire

Caused By A (Direct Or Nearby) Lighting Stike.

Lightning strike

Image Source:

View This Newcast Article About CSST Gas Lines’ Fires In Frisco, Texas.

Image Source: YouTube Embedded Video

Click On White Arrow In Center Of Image To View Video

SHOWN: Newcast Article About CSST Gas Lines’ Fires In Frisco, Texas.


This was Part-2 of our 2-Part article about Water Heater Installation Plumbing Code.  Al’s Plumbing, Heating & A/C in Plano, Texas Al’s offers full-service; plumbing maintenance, repairs, and replacements for every plumbing component in your home. 

Also, Al’s sells and installs gas & electric water heaters.   Al’s is near your home in Wylie, TX; Rowlette, TX; and Murphy, Texas.  We service all homes in northeastern Dallas County, TX, and southern Denton County, TX with no additional travel charges.

Al’s also provides maintenance & repairs for every brand of Central A/C, Gas & Electric Furnace, and Heat Pumps.  Additionally, we sell and install new HVAC Systems from American Standard (same company as Trane), Ameristar, and Coleman HVAC (same company as York HVAC).

Call Al’s today to discuss any concerns or problems you have with your HVAC System or Plumbing.

We will arrange an appointment at your convenience.