Supplemental instructions for gas water heaters installed in potable/space heating applications.
Local codes or plumbing authority requirements may vary from the instructions or diagrams provided in this manual and take precedent over these instructions.
Hot water |
supply to |
Combination Potable and Space Heating Application
| house | |
Hot water |
| |
supply to | From HOT | |
heating | ||
outlet on | ||
unit | ||
water heater | ||
|
Tee fitting for vertical hot water supply lines.
Hot water |
|
| From HOT | |
|
| outlet on | ||
supply to |
|
| ||
|
| water heater | ||
house |
|
| ||
|
|
| ||
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Hot water supply to heating unit
Tee fitting for horizontal hot water supply lines.
Tee fitting must be installed as shown. This ensures that any air in the water lines will be purged through the domestic water faucets and showers.
DANGER: When this system requires water for space heating at elevated temperatures (above 125°F [52°C.]), a mixing or tempering valve must be installed in the hot water supply line to the house in order to reduce the scald hazard potential.
DANGER: Any piping or components used in the installation of this water heater in a combination potable and space heating application must be suitable for use with drinking water.
DANGER: If this water heater is installed in an application intended to supply domestic hot water needs and hot water for space heating purposes, do not connect the heater to an existing heating unit or components of a heating system that have previously been used with a non drinking water system. Toxic chemicals such as those used for boiler treatment may be present and will contaminate the drinking water supply causing possible health risks. Never introduce toxic chemicals, such as those used for boiler treatment, into this system.
Typical Piping Diagram for Combination Potable/Space Heating Installation
Spring loaded check valve in heating unit hot water supply line and cold water return line (not supplied with water heater)
NOTE: This check valve is incorporated in some heating units. Refer to the installation instructions supplied with specific heating unit to determine if it is required.
Isolation valve in hot water supply line to heating unit (not supplied with water heater)
See diagrams above for proper pipe application for vertical or horizontal supply lines
Temperature and Pressure
Relief Valve
Gas line to water heater 
Water Heater Jacket 
Temperature and pressure relief valve discharge line
Combustion Air Inlet
Openings
Air vent |
|
|
| Domestic hot water supply |
|
|
Heat Trap
6” Min.
Mixing or |
|
tempering |
|
valve (refer |
|
to warning |
|
above) | |
| |
| Valve |
| Isolation valve in cold |
| water return line from |
| heating unit (not |
| supplied with water |
| heater) |
Cold water return line from heating unit
Hot water supply line into heating unit
Drain valve
(not supplied with water heater)
Incoming cold water supply
Thermal Expansion Tank (if
Heating unit
15
6” Air Gap