Domestic Hot Water Mode; Frost Protection; Pump; Low Water Pressure Sensor (Internal) - ECR International Dunkirk DCBF-75 Manual

!
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.

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.
• 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.
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

If electricity is connected to the boiler, regardless if
power is "On" or "Off" 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)

This 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 (0.5 bar).
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240013509 REV A, [03/15/2022]