Instructions / Assembly
IS-TWH-UT_UTS
Series TWH and LFTWH
Tankless Water Heater Service Valve Set
Sizes:
3
⁄4" and 1" (20-25mm)
Installation Instructions
Fig.4
STOP!
Before connecting any components, be sure to read all
of the tankless water heater manufacturer’s installation
instructions. Failure to follow instructions below can re-
sult in serious injury, death and/or property damage.
1. Identify all components and orientations
before beginning installation
1. HOT WATER SERVICE VALVE (Fig.1)
Identied by a RED ring on the upper
union connection and by the red
insulator handle.
2. COLD WATER SERVICE VALVE (Fig.2)
Identied by a blue ring on the upper
union connection and by the blue insulator
handle.
3. CHECK MODULE
Check element is integral to cold water
service valve in TWH-QC-HC or LFTWH-
QC-HC, TWH-UT-HC-RV or LFTWH-UT-
HC-RV and TWH-QC-HC-RV or
LFTWH-QC-HC-RV kits only.
4. PRESSURE RELIEF VALVE (Fig.3)
Identied by a silver test lever.
Note: ANSI Z21.22 and local
codes govern the installation
of pressure relief valves.
2. Before attaching any components
to the tankless water heater, attach
PRESSURE RELIEF VALVE to HOT
WATER SERVICE VALVE (Figure 4)
CAUTION: Do not over tighten relief valve.
Do not tighten more than 2 turns past
hand tight.
a. Apply thread sealant to the exposed
threads of the pressure relief valve.
b. Thread the pressure relief valve into the
3
⁄4" port on the side of the hot water valve
and hand tighten. Using a wrench, tighten
the pressure relief valve until the discharge
on the pressure relief valve is positioned
downward on the isolation valve, as shown
in Figure 4.
Drain Line
Attach this end to
tankless water heater
Attach this end to
tankless water heater
3. Install COLD WATER SERVICE VALVE onto cold water
inlet of tankless water heater
a. Locate the cold water threaded inlet on the tankless water
heater and apply thread sealant to the threads.
b. Slightly loosen the union nut on the top of the cold water
valve (i.e. the end with the blue insulator ring) so that the
union tailpiece rotates freely.
c. Holding the cold water valve beneath the cold water inlet,
thread the union tailpiece onto the inlet and hand tighten.
Using a wrench, tighten the union tailpiece. Next, position
the cold water valve with the purge port pointing forward,
towards the front of the water heater, and hand tighten the
union nut.
d. Verify that the blue insulator seats itself between the union
tailpiece and the union nut. Tighten the union nut with a
wrench, making sure that the valve does not rotate out of
position.
4. Install HOT WATER SERVICE VALVE onto hot water
outlet of tankless water heater
WARNING: There should not be a shutoff located between
the tankless water heater and pressure relief valve. (see
direction arrow in Fig. 5)
a. Locate the hot water threaded outlet on the tankless water
heater and apply thread sealant to the threads.
b. Slightly loosen the union nut on the top of the hot water valve
(i.e. the end with the red insulator ring) so that the union tail-
piece rotates freely.
c. Holding the hot water valve beneath the hot water outlet,
thread the union tailpiece onto the outlet and hand tighten.
Using a wrench, tighten the union tailpiece. Next, position the
hot valve with the purge port and pressure relief valve point-
ing forward, towards the front of the water heater, and hand
tighten the union nut. Verify that the insulator seats itself
between the union tailpiece and the union nut. Tighten the
union nut with a wrench, making sure that the valve does not
rotate out of position.
Fig.1
Fig.2
Fig.3
Hot Service Valve Purge Port Flow Data
ATTENTION INSTALLER: After installation, please leave
this Instruction Sheet for occupant’s information.
IMPORTANT: Inquire with governing authorities for
local installation requirements.
WARNING
!
For valves with CPVC or PEX end connections do not exceed
the tubing manufacturers pressure and temperature ratings.
Refer to the tubing manufacturers product specifications for
that information.
TWH-UT-UTS


