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3.7.2.
Relief Valve Piping
WARNING: Pressure relief valve discharge piping must
A
be piped near the floor and close to a drain to eliminate
the potential of severe burns. Do not pipe to any area
where freezing could occur. Refer to local codes.
3.7.3.
Temperature & Pressure Gauge
The temperature and pressure gauge is shipped threaded
onto the heater outlet assembly.
3.7.4.
Hydrostatic Test
Unlike many types of heaters, this heater does not require
hydrostatic testing prior to being placed in operation. The
heat exchanger has already been factory-tested and is
rated for 160 psi (1100 kPa) operating pressure. However,
Raypak does recommend hydrostatic testing of the piping
connections to the heater and the rest of the system
prior to operation. This is particularly true for hydronic
systems using expensive glycol-based anti-freeze. Raypak
recommends conducting the hydrostatic test before
connecting gas piping or electrical supply. Leaks must
be repaired at once to prevent damage to the heater.
NEVER use petroleum-based stop-leak compounds.
Isolate heater water connections from the system prior to
performing a hydrostatic test.
To perform hydrostatic test:
1. Connect fill water supply. Fill heater with water.
Carefully fill the rest of the system, making sure to
eliminate any entrapped air by using high-point
vents. Close feed valve. Test at standard operating
pressure for at least 24 hours.
2. Make sure constant gauge pressure has been
maintained throughout test.
3. Check for leaks. Repair any that are found.
3.7.5.
System Sensor Installation
The System Sensor (S3) is required for all piping
configurations unless the units firing rate will be controlled
by an external source such as our Temp Tracker MOD+
Hybrid sequencer. Proper placement and method of
installation are critical for proper operation of the system.
The sensor must be installed in a drywell in conjunction
with heat conductive compound as shown in Figure 13.
The drywell must be installed no more than 5 equivalent
feet (1.52 m) of pipe/tubing downstream of the de-coupler
and installed in such a way that ensures the sensor bulb is
in the flow path.
CAUTION: Be careful when installing the drywell not to
A
over-tighten the well as this can damage the well and may
prevent the sensor from fitting properly.
Locating the sensor on the outside of the pipe will slow
the unit's response and yield less accurate results. Use
18AWG wire minimum for sensor wiring.
NPT FITTING
THERMAL PASTE
4 PIPE DIA
NOT TO EXCEED
12 IN. (305 mm)
SYSTEM
PIPING
F10501
TO BOILER
Figure 13. System Sensor Installation
3.8. Raypak Integral Cold
Water Protection
XTherm heaters are equipped with an integral CWP
system that utilizes a Variable-Speed Pump or pumps to
inject just the right amount of water from the main system
loop into the heater loop to maintain the optimum inlet
temperature. This feature allows the system to achieve
and maintain a specific inlet temperature target.
XTherm H boiler models equipped with the dual-injector
pump system are designed to operate with heater inlet
water temperatures down to 50°F (10°C) continuous.
Under start-up conditions the dual-injector system can
operate with fluid temperatures down to 32°F (0°C).
Continuous operation below 50°F (10°C) return water
temperature may cause operational issues for the unit
as well as temperature control instability. XTherm WH
models equipped with the single-injector pump system
are constructed with materials appropriate for domestic
hot water operating conditions. XTherm P models are
equipped with a single-injector pump system and are
constructed with all nonferrous materials for rust-free
operation. Contact your local representative or the factory
for applications assistance.
For detailed information about CWP in VERSA-equipped
systems, see VERSA IC manual (5000.72).
CAUTION: Damage due to internal condensation may
A
occur if the primary heat exchanger inlet temperature
does not exceed 120°F (49°C) within 7 minutes of startup.
Warranty claims will be denied for damage or failures
caused by condensation.
DRYWELL
SYSTEM
SENSOR
5 FT. (1.5 M)
MAX
NOT TO SCALE
FROM BOILER
13
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