LAARS EDN Series - Installation, Operation and Maintenance Instructions - Manual (Page 14)

Page 14 LAARS Heating Systems Company
Figure 18. EBP Domestic Water Piping with Recirculating Loop.
WARNING
Failure to install a hot water tempering (mixing)
valve (12) creates a scalding hazard with potential
for serious bodily injury. Some brands of tempering
(mixing) valves are not designed as anti-scald valves.
Where domestic water is supplying multiple
apartments or large whirlpool tubs, an additional
storage tank may be connected as shown in Figure
17. The bronze circulator shown must be connected
to the tank aquastat and must not run continuously. If
the circulator is wired to run continuously, the unit’s
domestic water flow switch will keep the unit in
domestic water priority, and no water will be allowed
to be sent to the heating system.
Where domestic water is supplying a
recirculating loop, pipe per Figure 18. If the circulator
is wired to run continuously, the unit’s domestic
water flow switch will keep the unit in domestic
water priority, and no water will be sent to the heating
system. Wire the loop’s circulator through an aquastat
to maintain domestic water priority, while still
allowing the heating systems to function properly.
3.3 Anti-Freeze — Domestic Water
Endurance EBP units use a flat plate heat
exchanger to heat domestic (potable) water indirectly.
Endurance units are equipped with a Low Temperature
control feature that recognizes when the boiler
water temperature (not the domestic/potable water
temperature) has fallen below 39° (4°C). If this
condition is recognized, the Endurance pump will run
for 5 minutes, or until the boiler water temperature
reaches 45°F (7°C). If the boiler water temperature
remains below 45°F (7°C) for 5 minutes, the appliance
will start its ignition sequence, in hopes of firing, and
heating the boiler water. The display will show [ICE]
during this time.
This feature is intended to assist in protecting
the boiler from freezing conditions, and does not
help to protect any other part of the boiler or water
heater system. This feature will not help to protect the
domestic (potable) water in the system from freezing
conditions.
Caution
Power outage, interruption of gas supply, failure of
system components, activation of safety devices,
etc., may prevent a heater from firing. Any time a
heater is subjected to freezing conditions, and
the heater is not able to fire, and/or the water is
not able to circulate, there is a risk of freezing
in the heater or in the pipes in the system. When
water freezes, it expands. This can result in bursting
of pipes in the system, or damage to the heater,
which could result in leaking or flooding conditions.
SECTION 4.
Hydronic Heat Piping
4.1 Hydronic Piping
The appliance incorporates its own circulating
pump and bypass loop and is capable of providing
flow through heating zones, in addition to what
it needs for itself. Model size 110 is capable of
providing flow for two heating zones (up to 67 feet
of ¾" baseboard each), and model 175 is capable of
providing flow for four heating zones (up to 67 feet of
¾" baseboard, each).