Filter
Top Products
Relief Valve Piping
Hydrostatic Test
Unlike many types of heaters, this heater does not re-
quire hydrostatic testing prior to being placed in
operation. The heat exchanger has already been fac-
tory-tested and is rated for 160 psi operating pressure.
However, Raypak does recommend hydrostatic test-
ing 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.
To perform hydrostatic test:
1. Connect fill water supply. With bleed valve open,
fill heater with water. When water flows from bleed
valve, shut off water. Close bleed valve. 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 if found.
Cold Water Operation
This heater is equipped with a proprietary condensate
evaporation system which will evaporate any conden-
sate that may begin to accumulate inside the primary
heat exchanger with water temperatures as low as
120°F (49°C).
13
Heaters operated with an inlet temperature of less
than 120°F (49°C) MUST have a manual bypass (see
Fig. 14) or an approved low-temperature operation
system to prevent problems with condensation. This
piping is like a primary/secondary boiler installation
with a bypass acting as the secondary boiler piping.
Raypak strongly recommends that thermometer(s) be
placed into the heater piping next to the in/out header
to facilitate temperature adjustment. Inlet water tem-
peratures below 120°F (49°C) can excessively cool
the products of combustion, resulting in collection of
condensate in the heat exchanger area beyond the
capacity of the condensate evaporation system.
Failure to reach or exceed 120°F (49°C) within 7 min-
utes may damage or cause failure of the heat
exchanger, combustion chamber, or other parts within
the combustion chamber. It can cause operational
problems, bad combustion, sooting, flue gas leakage
and reduced service life of the vent system. A bypass
allows part of the heater discharge water to be mixed
with the cooler water returning to the heater inlet to
increase the heater inlet temperature above 120°F
(49°C). This precautionary measure should prevent
the products of combustion from condensing beyond
the ability of the condensate management system
employed in this heater in most installations. Warranty
claims will be denied for damage or failures
caused by condensation.
Cold water operation issues are applicable to both
cold water start and cold water run applications. Cold
water operation for 7 minutes or less on initial daily
start-up is acceptable. Where cold water starts will last
longer than 7 minutes or where cold water operation is
continuous, provisions must be made to mix higher
temperature outlet water with the colder inlet water
and thereby raise the inlet temperature to at least
120°F (49°C) within the 7-minute time limit.
Cold Water Starts
Cold water starts, wherein the inlet water temperature
remains below 120°F (49°C) for more than 7 minutes,
must
have cold water start protection. Known pro-
tection methods consist of mixing heated outlet water
with the inlet water with a bypass to raise the inlet to
120°F (49°C) or higher. Once the system is heated up
and has return water temperatures of 120°F (49°C) or
higher, the mixing of outlet water with inlet water is no
WARNING: Pressure relief valve discharge piping
must 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.
CAUTION: Damage due to internal condensation
may occur if the heater inlet water temperature does
not exceed 120°F (41°C) within 7 minutes of start-
up.
NOTE: Vent piping MUST contain a condensate
drain which is installed according to the vent
manufacturer’s instructions and plumbed to an
appropriate condensate management system (field
supplied).