Install Pressure Relief Valve - Rinnai RSC199i Installation And Operation Manual

4.8 Install Pressure Relief Valve

WARNING
4.8. 1 Guidelines
An approved pressure relief valve is required
by the American National Standard (ANSI
Z21.10.3) for all water heating systems and
shall be accessible for servicing. When
connecting a pressure relief valve, follow the
guidelines below:
• The pressure relief valve must comply
with the standard for Relief Valves and
Automatic Gas Shutoff Devices for Hot
Water Supply Systems ANSI Z21.22
and /or the standard Temperature,
Pressure, Temperature and Pressure
Relief Valves and Vacuum Relief
Valves, CAN1-4.4.
• The pressure relief valve must be
rated up to 150 psi and to at least the
maximum Btu/hr of the appliance.
• The discharge from the pressure relief
valve should be piped to the ground or
into a drain system per local codes.
• The pressure relief valve must be man-
ually operated once a year to check for
correct operation.
• The discharge line from the pressure
relief valve should pitch downward and
terminate 6 in. (152 mm) above drains
where discharge will be clearly visible.
• The discharge end of the line shall be
plain (unthreaded) and a minimum of
3/4 in. nominal pipe diameter. The dis-
charge line material must be suitable
for water at least 180° Fahrenheit.
• The pressure relief valve is assembled
to the pressure relief valve adapter as
illustrated on the next page. DO NOT
place any other valve or shut off device
between the pressure relief valve and
the water heater.
52
Water discharged from the pressure relief valve could cause severe
burns instantly or death from scalds.
Rinnai Tankless Water Heater Installation and Operation Manual
• If a pressure relief valve discharges peri-
odically, this may be due to thermal expan-
sion in a closed water supply system. Con-
tact the water supplier or local plumbing
inspector on how to correct this situation.
Do not plug the pressure relief valve.
• The American National Standard (ANSI
Z21.10.3) does not require a combination
temperature and pressure relief valve for
this appliance. However, local codes may
require a combination temperature and
pressure relief valve.
• Protect pressure relief valve and pressure
relief valve discharge line from freezing.
Do not plug or restrict flow of the pressure
relief valve.
• DO NOT plumb the pressure relief valve
with the condensate drain; both must be
plumbed independently to drain.
• DO NOT plug the pressure relief valve and
do not install any reducing fittings or other
restrictions in the relief line. The pressure
relief line should allow for complete drain-
age of the valve and the line.
• DO NOT place any other valve or shutoff
device between the pressure relief valve
and the water heater.