7.8102.5 Tankless Water Heater

Topic: 
Water Heating
Subtopic: 
Installation and Replacement
Desired Outcome: 
Provide a safe and reliable hot water source that meets the needs of the occupant/building management/building operations staff at the lowest possible life cycle cost
For supporting material, see Referenced Standards.
TitleSpecification(s)Objective(s)
7.8102.5a
Hazardous material removal

Health concerns in the removal and replacement of equipment (e.g., asbestos, other hazardous materials) will be identified

Upon the discovery of hazardous material, written notification and contact information for regional EPA EPA U.S. Environmental Protection Agency, www.epa.gov asbestos coordinator will be provided to appropriate people (e.g., occupant/building operations staff)

Property manager will be asked to contract with an EPA EPA U.S. Environmental Protection Agency, www.epa.gov -certified asbestos contractor to conduct abatement before decommissioning and replacement (property manager is responsible for abatement or remediation)

Remediate health hazards using EPA EPA U.S. Environmental Protection Agency, www.epa.gov -certified contractors

7.8102.5b
Decommissioning

Decommission the applicable system components by completing the following, in accordance with accepted industry procedures and practices:

  • Remove old water heater and associated components
  • Seal any unused chimney openings
  • Safely disconnect and secure any abandoned utility (fuel and electric) connections

Preserve the integrity of the building and services

Remove old equipment in a timely and efficient manner

7.8102.5c
New equipment installation

Tankless water heaters and associated components will be installed in accordance with local codes, accepted industry standards and practices, and manufacturer specifications

In instances where conflicts occur between the code and the manufacturer's installation instructions, the more restrictive provisions shall apply

Ensure the health and safety of the worker/occupant/building management/building operations staff

7.8102.5d
Emergency drain pan

In instances where, due to the installation location of the tankless water heater, a leak could cause damage building components, an emergency drain pan should be installed

A 3/4" drain line or larger will be connected to tapping on pan and run emergency drain line to floor drain, pump, or building exterior

Collect and safely dispose of water escaping from the appliance

7.8102.5e
Temperature and pressure relief valve

Correct temperature and pressure relief valve will be installed in accordance with manufacturer specifications

Equipment will be connected to properly sized discharge tube and run to a safe location no greater than 6" from the floor or as prescribed by local code (in the absence of local code, as prescribed by UPC)

Discharge excessive energy (pressure or temperature) from the appliance to a safe location

7.8102.5f
Dielectric unions (dielectric insulator)

Dielectric unions (dielectric insulator), if needed, will be installed in accordance with manufacturer specifications

Minimize corrosion between dissimilar metals

7.8102.5g
Stray voltage protection

Electrical connection to the water heating equipment should be made per manufacturer's instructions and per NEC NEC National Electrical Code ( NFPA NFPA National Fire Protection Association, www.nfpa.org 70)

Break the stray voltage electrical circuit through the appliance

7.8102.5h
Backflow prevention

Backflow prevention will be installed in accordance with manufacturer specifications and all applicable codes

Backflow devices shall be tested by a certified backflow assembly tester at the time of installation, repair, or relocation, and not less than on an annual schedule or more often where required by local code

Protect the water supply from contamination

7.8102.5i
Pressure verification

Building water pressure and volume will be verified as sufficient and will be in accordance with manufacturer specifications

A pressure regulator or booster pump will be installed as needed

Provide proper water pressure to the appliance

7.8102.5j
Pipe insulation

All piping and fittings will be insulated with fixed insulation to IECC IECC International Energy Conservation Code or ASHRAE ASHRAE American Society of Heating, Refrigerating and Air-Conditioning Engineers, www.ashrae.org 90.1, at a minimum

Reduce line losses

7.8102.5k
Required combustion air

Recommendations will be made to install all tankless appliances as sealed combustion

If not possible:

Combustion air shall be calculated and provided in conformance with the applicable code adopted by the jurisdiction and manufacturer's installation requirements

In instances where conflicts occur between the code and the manufacturer's installation instructions, the more restrictive provisions shall apply

In absence of a local code, combustion air shall be calculated and provided in conformance with any of the following: NFPA NFPA National Fire Protection Association, www.nfpa.org 54, IFGC IFGC International Fuel Gas Code , or NFPA NFPA National Fire Protection Association, www.nfpa.org 31

Ensure adequate combustion air for operation of the appliance

7.8102.5l
Venting of flue gases

Combustion byproducts shall be removed in accordance with the applicable code adopted by the jurisdiction and manufacturer's installation requirements

In instances where conflicts occur between the code and the manufacturer's installation instructions, the more restrictive provisions shall apply

In absence of a local code, combustion byproducts shall be removed in accordance with any of the following: NFPA NFPA National Fire Protection Association, www.nfpa.org 54, IFGC IFGC International Fuel Gas Code , or NFPA NFPA National Fire Protection Association, www.nfpa.org 31

Ensure the safety and durability of the venting system

7.8102.5m
Combustion testing

Undiluted flue gases will be checked with a calibrated flue gas analyzer in accordance with accepted protocol

If combustion is not happening safely or to maximum efficiency, diagnostics and adjustments will be done in accordance with manufacturer specifications and local codes

Confirm that combustion is occurring safely with maximum efficiency

7.8102.5n
Fuel supply

Electric, natural gas, and oil supply components will be installed to accepted industry standards and codes in accordance with NFPA NFPA National Fire Protection Association, www.nfpa.org 70 ( NEC NEC National Electrical Code ) for electric, NFPA NFPA National Fire Protection Association, www.nfpa.org 54 for gas, or NFPA NFPA National Fire Protection Association, www.nfpa.org 31 for oil

Energy input required by the appliance will be in accordance with manufacturer specifications (e.g., ensure gas pipe size and pressure are adequate)

Provide sufficient fuel to the water heater burner or element

7.8102.5o
Discharge water temperature

Discharge water temperature will be set not to exceed 120 °F or as prescribed by local code

Install mixing valve when higher storage/generation temperatures are required

Ensure water temperature is low enough to prevent scalding

Ensure water temperature is high enough to inhibit growth of pathogens (e.g., Legionella)

7.8102.5p
Commissioning of system

The following will be checked once the system has been connected and filled:

  • Safety controls
  • Combustion safety and efficiency
  • Operational controls
  • Fuel and water leaks
  • Cycle unit
  • Local code requirements
  • Other system components (e.g., expansion tank, storage tank)

Commissioning will be in accordance with manufacturer specifications and relevant industry standards

Ensure system functions safely and is designed with the lowest possible cost of ownership

7.8102.5q
Ambient carbon monoxide ( CO CO Carbon monoxide )

All spaces with combustion appliances will have a CO CO Carbon monoxide alarm

Locations of CO CO Carbon monoxide alarms in the space shall be in accordance with state law and local codes

Ambient CO CO Carbon monoxide levels will be maintained under code-acceptable thresholds

Ensure worker, occupant, and building management staff health and safety

7.8102.5r
Education

Completed work will be reviewed

Occupant/building operations staff/property manager will be educated on the safe and efficient operation and maintenance of the system, including:

  • Adjustment of water temperature
  • Operation of backflow preventer and pressure regulator
  • Importance of keeping operating manuals accessible

Educate occupant/building operations staff/property manager about the safe, efficient operation and maintenance of the system