Connect Tankless Heater Piping
Hot Water Can Scald!
•Consumer Product Safety Commission and some states recommend domestic hot water temperature of 130°F or less.
•When installing an automatic mixing valve, selection and installation must comply with valve manufacturer’s recommendations and instructions.
•Water heated to a temperature suitable for clothes washing, dish washing and other sanitizing needs will scald and cause injury.
•Children and elderly, infirm or physically handicapped persons are more likely to be injured by hot water. Never leave them unattended in or near a bathtub, shower or sink. Never allow small children to use a hot water faucet or draw their own bath. If anyone using hot water in the building fits this description, or if state laws or local codes require certain water temperatures at hot water faucets, take special precautions:
—Install automatic mixing valve set according to those standards.
—Use lowest practical temperature setting.
—Check water temperature immediately after first heating cycle and after any adjustment.
Studies have indicated that dangerous bacteria can form in
potable water distribution systems if certain minimum water temperatures are not maintained. Contact local health department for more information.
To pipe tankless heater:
1.Size piping no smaller than tankless heater inlet and outlet.
2.Following controls (furnished by others) must be installed:
a.Automatic mixing valve. See FIGURE 12.
(Read 
at left.)
b.Flow regulating valve. Size according to intermittent draw of tankless heater. See Table below. Follow valve manufacturer’s instructions to install.
3.Additional
4.In hard water areas, soften cold domestic supply water to heaters to prevent lime
TANKLESS HEATER RATINGS TABLE
|
|
|
|
|
|
|
|
| BOILER |
|
|
| INTERMITTENT | INLET |
|
| MODEL |
| HEATER |
| DRAW RATINGS | AND OUTLET |
|
| NUMBER * |
| NUMBER |
| (GPM) * * | TAPPING SIZES |
|
|
|
|
|
|
|
| |
|
| 3.25 | ¾" |
| |||
|
| 3.50 | ¾" |
| |||
|
| 3.75 | ¾" |
| |||
|
| 4.00 | ¾" |
| |||
|
| 4.00 | ¾" |
| |||
|
| 4.00 | ¾" |
| |||
|
| 4.00 | ¾" |
| |||
|
|
|
|
|
|
|
|
*To avoid supplying steam to system during summer tankless operation, raise water level to one inch above normal water line.
** Gallons of water per minute heated from 40°F to 140°F with 200°F boiler water temperature. Tested in accordance with I=W=H Testing and Rating Standard for Indirect Tankless Water Heaters Tested with Boilers.
