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This is the second half of an article about water heater code.  These codes specify where and how a water heater must be installed.

Al’s Plumbing, Heating & A/C in Plano, Texas 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 (same company as American Standard) and Coleman HVAC (same company as York HVAC).

Al’s also provides full service plumbing maintenance, repairs and replacements for every plumbing component in your home.  Al’s sells and installs Rheem Profressional Series gas & electric water heaters, and tankless water heaters.

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, and offer 24/7 Emergency Service.

 

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

 

Texas Code For Water Heater Code For Installation

Click Here to see the 2015 Texas Plumbing Codes: Up.codes 2015 Chapter 5 – Water Heaters    Note: The 2018 International Building Codes (IBC) may include updates to what is shown with the link.

GAS WATER HEATER CODE (continued)

  • Combustion Air IRC 2407.7 — Gas Water Heater Installation in a water heater closet:

Water Heater Code requires the water heater installation must include two ducts be installed to provide combustion air from the attic to a water heater equipment closet;

  • one terminating near the ceiling
  • one terminating near the floor
  • The high one will mostly provide air for the exhaust gases to vent out safely.
  • The low one will mostly provide air for gas combustion-air while the water heater is heating.

Water heater code for gas water heaters requires conforming to the requirements of the International Fuel Gas Code.   Gas Water heater installation shall be installed in accordance with the manufacturer’s instructions

photo of combustion supply air ducts for water heater closet

Shown: Combustion-Air Intake Vents For Gas Water Heater

WHY?:  Carbon Monoxide Danger.  If sufficient combustion & exhaust air supply is not available, the exhaust won’t rise through the flue and out of the house. 

steamed mirror shows water heater not venting to outside properly

Shown: Steam On Mirror Shows This Gas Water Heater Is Not Safely Venting Exhaust Gasses Out Of The House (Known As Back-Drafting)

 

  • Double-Wall (Type B) Metal Vent Pipe For Exhaust.  Water Heater Code requires the rise-length of the metal pipe may vary by municipality.  It’s often 5 feet between vent hood (attached to top of water heater) and vent cap (on the roof, outside the home).

photo of water heater installed in attic

Shown: Silver Metal Vent Pipes Connecting Water Heater To Home Exhaust Venting

photo of water heater vent hood and exhaust pipe

Shown: Water Heater Vent Hood (see red arrow).  Note: Appearance Varies.

water heater vent cap

Shown: Water Heater Vent Cap.  Note: Appearance Varies.

 

Water Pipe Insulation: Water Heater Code requires the first 5 feet of hot and cold water pipes are required to be insulated if they are exposed in unconditioned space.

photo of combustion supply air ducts for water heater closet

Shown: Water Pipe Insulation (black) Is Installed On Exposed Water Pipes.

ELECTRIC WATER HEATER CODE

Water Heater Code requires electric water heaters to conform to the requirements of this code and provisions of NFPA70.

422.31(a)

1. Article 422.31(a) of the National Electric Code defines the means of disconnection for permanently connected electrical appliances (rated up to 300 amps):

These appliances can be disconnected by a circuit breaker, with no additional means of disconnection required.

Residential water heaters are typically 4,500 – 5,500 watts.  WATTS divided by VOLTS = AMPS       4,500 / 240 = 18.75 AMPS

 

2. Water Heater Code requires an electric water heater have a disconnect within the immediate vicinity of the water heater unless:

  • The circuit breaker is within view from the water heater (within 50 feet, with an unobstructed view)

OR

  • There is a proper locking device present at the circuit breaker.

Note:  The lockout device will not interfere with the operation of the circuit breaker.  If the circuit breaker trips, the power is shut off regardless of whether the breaker’s handle is allowed to move.

photo of circuit breaker lock out

Shown: Circuit Breaker Lock Out Device

WHY?:  If electricity was turned back on during water heater service, an an electrical shock or electrocution could occur.

 

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

Water heater code requires a Temperature & Pressure (T&P) Relieve Valve.   The T & P Valve will open at a predetermined pressure (150 PSI in most cases) and/or a predetermined temperature (210F in most cases).  The valve allows pressurized hot water to escape from the tank until the pressure and/or temperature drops below the valve’s pre-set levels.  Then the valve closes.

504.17  Water Heater Code requires the discharge piping serving a T & P valve shall be one nominal size larger than the size of the T&P valve outlet, where the relief valve discharge piping is installed. The outlet end of such tubing shall be fastened in place.

photo of water heater installed incorrectly with pressure relief valve downspout missing

This Water Heater Is NOT Installed Correctly And Is NOT In Compliance With IBC-2018 Code Requirements

It Is Missing The Pipe Connected To The T & Pressure Valve And Heading Downward Toward The Floor (valve it’s to the right of the red tag)

Shown: Pipe (heading toward the floor) is connected to the Pressure Relief Valve, As Required By Code

 

WHY?:  If The Pressure-Relief Valve Opens (due to high pressure inside the storage tank), It Can Send Scaling Water In All Directions From Near The Water Heater’s Top. 

The Connected Pipe Is To Ensure Scalding Water Discharges Safely At The Floor, with a drain nearby or discharges in to the pan the water heater sits within (the pan is connected to a drain line).

 

Drainage Pan (For All Water Heaters Located Where Water Will Cause Damage)

  • GAS

504.7  Water Heater Code requires a drain-pan under the water heater if it is installed in an area where water can cause damage.

Where a GAS storage tank-type water heater is installed in a location where water leakage from the tank will cause water-damage, the tank shall be installed in a galvanized steel pan having a material thickness of not less than 0.0236 inch

  • ELECTRIC

Water Heater Code allows an ELECTRIC storage water heater can be placed in a plastic pan not less than 0.036 inch in thickness.  A plastic pan shall NOT be installed beneath a gas-fired water heater.

photo of water heater installed in attic

 

WHY?:  The drainage pan provides a safe avenue for scalding hot water to be drained away.  If the water heater is in an attic, without this pan, scalding hot water could come through the ceiling into the living space.

Thermal Expansion Tank 

photo of water heater with expansion tank and pressure relief valve indentified

607.3  Thermal Expansion Tank

Water Heater Code requires a thermal expansion tank be installed where a storage water heater is supplied with cold water that passes through; a check valve, pressure-reducing valve or backflow-preventer, a thermal expansion tank shall be connected to the water heater’s cold water supply pipe in a location beyond these devices.

Thermal expansion tanks shall be sized in accordance with the tank manufacturer’s instructions and shall be sized such that pressure in the water distribution system shall not exceed that required by Section 604.8.

diagram of water heater and thermal expansion tank shown

Shown: Diagram Showing Water Heater & Thermal Expansion Tank Connected To Each Other

A standard water storage tank water heater can stress plumbing due to the normal thermal expansion of water when it’s heated.  A thermal expansion tank can help minimize the risk of pressure damage to the entire plumbing system.

It’s estimated that 50 gallons of cold water expands to 52 gallons when heated to 120°F. The water heater creates extra water-volume each time it heats the water.  The extra water volume can create excess pressure in the plumbing system, possibly causing damage to the water heater and the water pipes.  The water heater thermal expansion tank provides a place for excess water volume.

When the water (inside the water heater) heats up, the additional water volume moves into the thermal expansion tank.  When the water (inside the water heater) cools,  the water is moved from the thermal expansion tank back into the water heater’s storage tank.

WHY?  The thermal expansion tank eliminates the pressure (of expanded water volume) putting avoidable stress on the water heater and the water pipes connected to it.   The elimination of the pressure reduces the chance of leaks in both the water heater and water pipes connected to it.

link   https://www.fastwaterheater.com/water-heaters/common-codes/

 

  • Electrical Bonding Of Water Pipes:  Water Heater Code requires bonding of the hot cold and gas water piping with 6 AWG wire and clamps will successfully ground all water pipes.  This prevents electrical energy (from lightning or degraded electrical wires) from energizing water pipes.

photo of water heater water pipes bonded with copper wire

Shown: Bonding Of Both Hot & Cold Water Pipes

Cold Water Shut-Off Valve At Water Heater

diagram shows gate valve and ball valve side by side on water pipe

Shown: Diagram Shows Ball Valve (Green Handle) &  Gate Valve (Red Handle) Side By Side

 

2018 IPC Chapter 6: Water Supply and Distribution Code Section

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

606.2 Location of shutoff valves. Shutoff valves shall be installed in the following locations:

  • On the fixture supply to each plumbing fixture (other than bathtubs and showers) in one- and two-family residential homes.
  • On the water supply pipe to each sillcock (outdoor water faucet).
  • On the water supply pipe to each appliance or mechanical equipment.
  • Installing a dedicated water shutoff for water heater that allows water to be turned off water to only the water heater, not the entire home.
  • Individual water supplies shall be constructed and installed in accordance with the applicable state and local laws. Where such laws do not address all of the requirements set forth in NGWA-01, individual water supplies shall comply with NGWA-01 for those requirements not addressed by state and local laws.

 

  • Type Of Shut Off Valve

Though national water heater code does not specify which type of value be installed, Ball Water Valves may be specified in a local municipality’s plumbing code.  

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

 

Problems With Gate Water Valves

   cut away diagram of inside of gate water valve  gate water valve failed due to corrosion

Shown:  Gate Water Valve                                                      Cut-Away View Of Gate Water Valve                         Failed Gate Water Valve Due To Corrosion

  • When closing a gate water valve, the gate comes downward as the handle is turned.
  • It’s common for sediment or other debris to get in the way, resulting in the valve’s inability to close completely.
  • Because all the parts inside are brass, corrosion occurs over time, and can “freeze” the valve (not allowing the handle to turn).
  • Either of these conditions results in a failed gate valve.

 

Ball Water Shut Off Valve

photo of ball water shut off valve

Shown: Photo Of Exterior Of Ball Water Shut-Off Valve

diagram of a ball water shut off valve with inside exposed

Shown: Cut-Away View Of Ball Water Shut-Off Valve

  • Ball valves have a plastic or stainless-steel ball with a hole in the center (where the water flows through).
  • Debris does not have a place to settle like in the bottom of a gate valve.
  • Because the ball is plastic or stainless-steel, corrosion is quite limited.
  • These features make ball valves more long lasting and reliable.

The ball valve is the typical water heater cold water shut off valve today.  Ball valves have offer benefits not found in a gate valve.  The user can see at a glance if the valve is open or closed.   When the handle aligns with the direction of the water pipe, the valve is open. When the handle is perpendicular to the pipe, the valve is closed.  The stem (the shut off lever is attached to) is sealed by a rubber O-Ring under nut.   Ball valves are notably less prone to failure than gate valves

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

 

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Al’s Plumbing, Heating & A/C in Plano, Texas 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 (same company as American Standard) and Coleman HVAC (same company as York HVAC).

Al’s also provides full service plumbing maintenance, repairs and replacements for every plumbing component in your home.  Al’s sells and installs Rheem Profressional Series gas & electric water heaters, and tankless water heaters.

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, and offer 24/7 Emergency Service.