ECR International Dunkirk DCB-100, Installation, Operation & Maintenance Manual

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10.4 Domestic Hot Water Mode
Combi Boilers – Models 115, 150 & 205
• Domestic hot water call for heat is initiated when a faucet
is opened and water flow is sensed by boiler's DHW flow
switch.
• 3-way valve diverts boiler water to domestic hot water
(DHW) heat exchanger (Brazed-plate) to heat incoming
domestic water.
• Combustion fan come on at ignition speed, closing the air
pressure switch (150 model only), allowing power to flow
to the spark generator and gas valve, creating ignition in
the combustion chamber.
10 - OPERATING INSTRUCTIONS
10.5 Frost Protection
Boiler monitors supply and return water temperatures to
enable frost protection which automatically turns boiler and
pump on.
If water in boiler falls below 41°F (5°C), providing boiler is
connected to power, boiler will operate until water temperature
in the system reaches approximately 86°F (30°C).
Frost protection is for boiler only and not for complete Central
Heating System.
10.6 Pump and Models Equipped with Three way
Valve
If electricity is connected to the boiler, regardless if boiler
power is "On" and has not operated for 24 hours for heating
or hot water, boiler pump will operate automatically for one
minute every 24 hours.
10.7 Low Water Pressure Sensor (Internal)
Device protects primary exchanger from damage. It will not
allow boiler to run in a LOW water pressure situation. Low water
condition occurs when water pressure drops below 7.0 psi .
• Flame sensor senses flame in combustion chamber and
sends a signal to the control board.
• Control board monitors boiler water and
DHWtemperatures, modulates fan speed and gas rate
accordingly.
• Domestic call for heat ends when faucet is closed and
DHW flow switch does not see water flow.
Heat Only Boilers – Models 75, 100 & 125 with Indirect
Tank
• When the boiler receives a call for hot water from the
Indirect tank Aquastat or Tank Sensor, the 3-Way valve
diverts water from the heating system to dedicated
Indirect tank supply to heat domestic water in the tank.
• Combustion fan comes on at ignition speed, closing the air
pressure switch (125 model only), allowing power to flow
to spark generator and gas valve, creating ignition in the
combustion chamber.
• Flame sensor will sense flame in combustion chamber and
send a signal to the control board.
• Control board monitors boiler water and DHW
temperatures and modulates fan speed and gas rate
accordingly.
• Call for domestic water heating ends when the aquastat or
tank sensor is satisfied.
Heat Only Boiler 165
165 boiler does not have a 3-Way Valve. When paired with
an Indirect tank, the tank is a separate heat zone. The
Indirect tank is controlled by a field supplied multi zone
relay, priority is determined by the relay settings.
WARNING
Burn, Scald Hazard! Water temperature over 125°F
(51°C) can cause severe burns and scalding. See
User's Manual before setting water temperature.
Failure to follow these instructions could result in death
or serious injury.
!
240013501 REV A [03/15/2022]