Raypak 302B-902B User Manual
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Potable Water and Space Heating
1. All piping materials and components connected to
the water heater for the space heating application
shall be suitable for use with potable water.
2. Toxic chemicals, such as used for boiler treatment,
shall not be introduced into the potable water used
for space heating.
3. If the heater will be used to supply potable water,
it shall not be connected to any heating system or
components previously used with a non-potable
water heating appliance.
CAUTION: When this heater is used for both
potable water and space heating, observe the
following to ensure proper operation.
TANK SENSOR
Fig. 13: Single Domestic Hot Water Heater and Storage
Tank
Table I: Domestic Water Heater Flow Rate Requirements
4. When the system requires water for space heating
at temperatures higher than 140°F, a means such
as a mixing valve shall be installed to temper the
water in order to reduce scald hazard potential.
Pool Heating
The Hi Delta pool heater is equipped with an external
pump and bypass arrangement as standard equip-
ment. This arrangement blends outlet water with the
inlet water to increase the inlet water temperature,
thereby reducing the likelihood of condensation form-
ing on the heat exchanger. The pump also serves to
circulate water through the heater from the main sys-
tem piping.
To complete the installation of the pool heater, the pool
thermostat needs to be installed in the main return wa-
ter line, upstream of the heater. This will ensure that
the heater will be energized at the right time. If the
main water line is too far away from the heater and the
capillary bulb will not reach it, locate the pool thermo-
stat adjacent to the main line and run wires back to the
heater.
CAUTION: Power to the heater should be
interlocked with the main system pump to make sure
the heater does not fire without the main system
pump in operation. Improper flow control can
damage the heater. Uncontrolled flow (too high) or
restricted flow (too low) can seriously damage the
heater. Follow these instructions to make sure your
heater is properly installed.
∆T = Temperature rise, °F
∆P = Pressure drop through heat exchanger, ft
SHL = System head loss, ft. Includes 50 eq ft of tubing each way (total 100 eq ft).
gpm = Gallons per minute, flow rate
MTS = Minimum tubing size
*Must utilize optional cupro-nickel tubes. If over 25 grains per gallon, a water softener/treatment system must be utilized.
Caution: For scale free operation with "Hard Water" (16-25 grains per gallon of total hardness), the operating control must NOT be
set higher than 130 F. For higher than 130 F operation, a water softener/treatment system must be utilized.
Model
No.
Soft (0-4 grains per gallon) Medium (5-15 grains per gallon) Hard* (16+ grains per gallon)
∆T gpm ∆P MTS SHL
∆T
gpm
∆P
MTS SHL
∆T gpm ∆P MTS SHL
302B
13
40
2.0
2
5.1
10
52
3.3
2
8.3
7
74
6.4
2
16.3
402B
17
40
2.0
2
5.1
13
52
3.4
2
8.4
9
74
6.8
2
16.4
502B
21
40
2.1
2
5.2
16
52
3.5
2
8.6
12
73
6.9
2
16.3
652B
28
40
2.2
2
5.3
20
55
4.1
2
9.7
15
72
7.0
2
16.2
752B
30
42
2.6
2
6.0
20
73
7.5
2
16.9
14
90
11.3
2
25.1
902B
30
51
3.9
2
8.7
20
73
7.8
2
17.2
17
90
11.7
2
25.5