Eco-King HWB-299, Installation And Service Manual

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E93.1801EN171 HWB installation manual 28
NON-Return valve.
All water heaters HWB-299, HWB-399 and HWB499 have a non-return valve installed in the gas-air mixing pipe
just before the burner. Flue gas recirculation is prevented by the non-return valve. The prevention of recirculation
also reduces standby loses through the flue of the water heater. This creates a higher thermal efficiency.
Pump functionality
Delta T monitoring:
A high temperature difference between supply and return of the water heater can indicate a clogged heat ex-
changer or filter, or a defective pump. The burner load automatically decreases when the Return/Supply temper-
ature differential increases too much.
A
t maximum burner power ΔT is limited to 32.4 °F (18 ⁰ C) and at low burner power a ΔT above 46.8 °F (26 ⁰
C) is
not allowed. Above these values the water heater modulates down until the temperature difference is between
32.4 °F (18
⁰
C) °F and 46.8 °F (26
⁰
C)
°F. If the ΔT exceeds 55.6 °F (31
⁰
C), the water heater will be temporarily
switched off.
Frost protection
The water heater has a built-in frost protection that is automatically activates the water heater pump when the
water heater return (water) temperature drops below 50 °F/10 °C (programmable). When the water heater Inlet
temperature drops below the 41 °F/5 °C (programmable), the water heater is also ignited. The pump and/or water
heater will shut down as soon as the Inlet temperature has reached the 59 °F/15 °C (programmable). The men-
tioned temperatures are related to the temperatures measured by the INLET sensor of the water heater. This frost
protection function will not fire up the water heater in case of a “general blocking” of the water heater demand.
NOTICE: - This frost protection function is only protecting the water heater and not the whole sanitary system.
- This frost protection function is only useable provided that water circulation through the system is
possible - if not, the water heater goes in a lock-out.
- Because it concerns a programmable setting, a water heater damaged by frost is not covered un-
der warranty.
When mounting the bottom part of the condensate trap, before commissioning the water
heater and/or after maintenance, the condensate trap must
ALWAYS be completely filled
with water. This is a safety measure: the water in the condensate trap keeps the flue
gases from leaking out of the heat exchanger via the condensate drain.
WARNING
The condensate trap must al-
ways be filled to the edge with
water, before replacing to the
unit.
WARNING