Weil-McLain GOLD CGt Manual page 26

GOLD CGt Gas-Fired Water Boiler — Boiler Manual
4e
Water piping — connect tankless heater
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 scaled and cause injury
• Children, 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:
•
•
•
Studies have indicated that dangerous bacteria can
form in potable water distribution system if certain
minimum water temperatures are not maintained.
Contact local health department for more information.
These single wall heat exchangers comply with National
Standard Plumbing Code provided that:
• Boiler water (including additives) is practically non-
toxic, having a toxicity rating or class of 1, as listed
in Clinical Toxicology of Commercial Products.
• Boiler water pressure is limited to maximum 30 psig
by approved water relief valve.
If boiler is installed in a closet, it is recommended to
insulate the supply piping of domestic hot water to lower
closet air temperature.
26
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.
To pipe tankless heater:
1. Size piping no smaller than tankless heater inlet and
outlet.
2. The following controls (furnished by others) must
be installed:
a. Automatic mixing valve see Figure 22, below.
Read at left.
DANGER
b. Flow regulating valve. Size according to
intermittent draw of tankless heater. See
Table below. Follow valve manufacturer's
instructions to install.
3. Additional anti-scald devices may be installed at
each hot water faucet, bath and shower outlet.
4. In hard water areas, soften cold domestic supply
water to heaters to prevent lime build-up.
To set tankless heater low
limit:
1. Adjust setpoint dial to 190°F - 200°F. The boiler high
limit should be set 20°F higher.
Table 6 Tankless heater rating table
Boiler Heater Intermittent draw
model number ratings (GPM)
number Note 1
CGt
Note 1: 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."
Figure 22 Tankless heater piping
Cold water supply
Flow
regulating
valve
12"
minimum
(for thermal
DHW to
syphon)
system
Mixed
Hot
Cold
Automatic
mixing valve
071047
Part Number 550-110-290/0501
Inlet and
outlet tapping
sizes
2.6 ¾"
Out
In
Tankless heater
low limit control