Glow T150 & T180
Tankless Condensing Water Heater
35
manufacturer’s or local code requirements, install
and tighten the pressure relief valve into the 3/4”
female NPT connection located next to the drain
valve. Position the outlet of the pressure relief valve
downward.
Repeat the above procedures to install the HOT
water isolation outlet valve assembly onto the hot
water outlet connection of the water heater.
3.6.3 Pressure Relief Valve Installation,
Operation and Maintenance
DO NOT PLUG THE PRESSURE
RELIEF VALVE!
When tightening the pressure relief valve into
the hot water isolation valve, make sure to place
the wrench’s jaws on the relief valve’s wrench flats.
Applying force on any other part of the valve’s body
may cause irreparable damage.
Figure 3.16 - Optional Service Kit
Figure 3.17 - Pressure Relief Valve and Isolation Valves
NOTE: Must be rated for water heater use. The relief valve
must have a rating capacity of 500,000 BTU/H and 150/PSI
pressure rating.
MENU
UP
ENTER
DOWN
RESET
OVER
FLOW
TUBE
PRESSURE
RELIEF
VALVE
COLD
WATER
VALVE
HOT
WATER
VALVE
ROTATE
CLOCKWISE
FOR SERVICE
DOMESTIC HOT
WATER OUT
DOMESTIC COLD
WATER IN
Δ
Do not install any manually operated shutoff
valves between the relief valve’s inlet or outlet
connections and associated water heater or
discharge piping connections. Install the relief
valve’s inlet connection directly into the tankless
hot water heater isolation valve’s designated
connection only. An unobstructed flow path must
exist between the pressure relief valve and water
heater in order for the relief valve to function
properly.
Δ
The outlet connection of the pressure relief
valve must face downward, requiring a vertical
discharge pipe. In accordance with IPC code
requirement 504.6, install a suitable-length nipple
as a discharge pipe, into the female NPT outlet of
the pressure relief valve.
Δ
Do not reduce the 3/4” nominal pipe size (NPS) at
any length of the piping. The end of the discharge
pipe must not be threaded and must remain open
and unobstructed.
Δ
The discharge piping must not contain low points,
which may trap water. The piping must allow
complete drainage.
Δ
The discharge piping must discharge into a
suitable open drain and must not be allowed to
freeze.
Operation
In the event that the tankless water heater and its
piping system exceed designed pressure limits,
the pressure relief valve will automatically open,
discharging large amounts of very hot water. Correct
installation of the discharge piping and drainage are
critical in avoiding a scalding danger or water damage.
Maintenance
Annually inspect the end of the discharge piping for
signs of relief valve leakage. Carefully lift the spring-
loaded lever and center it horizontally against the
identification disc, allowing hot water to flow from the
end of the discharge pipe, into the drain. CAUTION!
Discharged water is extremely hot and can scald!
Avoid contact with the water. After a few seconds, flip
the lever back down, closing the valve. If the pressure
relief valve fails to flow water when opened or fails to
re-seat when closed, contact a qualified installer for
valve replacement.
For safe operation of the water heater, ensure that:
Δ
The pressure rating of the relief valve must not
exceed 150psi.
Δ The BTUH rating on the relief valve must equal or
Summary of Contents for T-150
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