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Applications space heating applications, Re-circulation – John Wood Takagi - 710 User Manual

Page 29

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29

APPLICATIONS
Space Heating Applications

WARNING

Toxic chemicals used in boiler treat-
ments such as alcohol, glycerol and
glycol group must not be introduced
into the system when used for open
loop potable water and space heat-
ing.
The 710 can be used to supply pota-
ble water and space heating and shall
not be connected to any heating sys-
tem 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 high-
er 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 52°C (125 °F)
can cause severe burns instantly or
death from scalds.
Chemicals such as diluted Glycol can
be used for radiant floor, Hydro/fan
coil air or Baseboard heating only.
The diluted solution of glycol must
contain between 25% and 55% of
Glycol. Be aware that in closed-loop
glycol systems, low pressure in the
heat exchanger can cause low-tem-
perature boiling, resulting in exces-
sive noise and damage to the water
heater. Consult with the glycol maker
for specifications prior to use.

Re-circulation

The recirculation pump is to be controlled by:
• Dual-set aquastat (recommended w/timer)

OR

• 710 Pump Control set to “Recirculation Mode”
The recirculation pump is to provide no less than 7.5 l/min
(2 GPM (US)) and no more than 15 l/min (4 GPM (US))
through each activated unit in the system.

This is a concept

drawing only.

Dual-purpose hot water heating
(Domestic and Space Heating)

Takagi

Unions

4" Gas Exhaust Vent (Discharge
Must Comply with Local and
State Codes). Can Not Be
Common Vented with Other
Appliances

Atmospheric
Vacuum Breaker

Pump (Must Be Sized Properly With
Each Application). Pump Shall Run

60 Seconds Every 6 Hours

Pressure

Gauge

Apply Correct

Thermal Expansion

Tank-Size Per Application

Tempered

Water To

House

Cold Inlet

Shut-Off

Valve

Check Valve Will
Have 1/8" Hole in
Check, As Per
Mass. Code

Thermometer

Thermostatic

Mixing Valve

Shut-Off
Valves

Check Valve

Hot
Water
Outlet

Cold

Water

Inlet

T-Handle Gas

Shut-Off Valve

**Maximum allowable distance of

50-Ft. from water heater and

heating panel

Heating Coil

(used with air-handler)

Diagramatic Layout of Radiant Heating and

Domestic Water Heater Per Mass. Code

Thermometer

Gas
Inlet

Drain

Plug

Water
Filter

120 VAC Switch
or Outlet

Inlet

An approved Pressure Only
Relief Valve, Tie to Location
approved by Local Codes and
Must Meet BTU Rating of
Takagi Model Used

Check
Valves

T

P

The circulation pump is to provide no less than 7.5 l/min
(2 GPM (US)) and no more than 15 l/min (4 GPM (US))
through each activated unit in the system.

Priority Control Devices such as a flow switch, an Aquastat
or other electronic controller can be used to prioritize the
domestic water system over the heating system.
Warning: Follow all local codes, or in the absence of
local codes, follow the most recent edition of the National
Plumbing Code.
Warning: This illustration is a concept design only. There
are a wide variety of variations to the application of controls
and equipment presented. Designers must add all neces-
sary safety and auxiliary equipment to conform to code
requirements and design practice. For more details, contact
the manufacturer.