Takagi AT-D3U-IN - Applications; Space Heating Applications; Recirculation

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APPLICATIONS
SPACE-HEATING APPLICATIONS
RECIRCULATION
*The recirculation pump is to be controlled by:
-Dual-set aquastat (recommended w/timer)
• The aquastat's differential should be a minimum of 10 °F (5 °C).
*The recirculation pump is to provide no less than 2 GPM (7.5 L/min) and no more than 4 GPM (15 L/min) through
each activated unit in the system. Refer to the heaters specification sheet on the manufacturer's website for
pressure drop information.
 This water heater is suitable for combination water (potable) heating and space
heating and not suitable for space heating applications only.
 In order to purge air in water pipes within a closed-loop system, an air vent and
air separator should be installed in the system. Required circulation flow rates are
labeled next to each application diagram. These flow rate requirements must be
followed.
 Toxic chemicals used in boiler treatments such as alcohol, glycerol and glycol groups
must not be introduced into the system.
 The water heater can be used to supply combination potable water and space
heating and shall not be connected to any heating system or component(s)
previously used with non-potable water where any chemicals were added to the
water heating appliances.
 When the system requires water for space heating at temperatures higher than
required for other uses, a means such as a mixing valve shall be installed to temper
the water for those other uses in order to reduce scald hazard potential.
 Water temperature over 125 °F (52 °C) can cause severe burns instantly or death
from scalding.
WARNING
Air vent


pump
Air
separator
S
Check valve
Check valve
Y-Strainer
Cold water inlet
Expansion tank
Gas supply
Ball valves
Unions
Hot water outlet Cold water inlet
Gas inlet
Pressure
relief valve
This is a concept drawing only.
Applicaons