Eco-King HWB-299, Installation And Service Manual

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E93.1801EN171 HWB installation manual 29
Water quality
In direct water heating appliances, the water flows directly through the heat exchanger of the water
heater. Because all the time fresh water, containing dissolved minerals, is heated, scaling may
occur. To prevent this, water quality must meet a number of standards.
The values are the following:
Water temperature max. = 160°F
Maximum allowed water hardness is 205 PPM or 205 mg/L CaCO
3
(= 11,5°dH)
TDS (total dissolved solids) may not exceed 450 PPM
Water hardness and TDS together may not exceed 450 PPM
The pH value of the water may not be under 6,5 and not above 7,5 (measured cold)
If water hardness is too high a water softening system is necessary.
If TDS alone or the combined value is higher than the abovementioned, the water should be heated
by means of an indirect water heating appliance.
Minimum water hardness = 80 PPM or 80 mg/L CaCO
3
(= 4.5°dH)
Minimum TDS = 100 PPM
Water that’s under these minimum values normally has a pH value which is aggressive and corro-
sive.
If water quality doesn’t meet the abovementioned requirements, a water treatment installation
should be installed to improve water quality to the required levels, if possible
.
Flush the system with fresh water
When a water heater is installed in a new system or an existing installation the system must be cleaned before the
water heater is installed. The system should then be drained and thoroughly flushed with clean water to remove
any debris. The water of the water heater and heating circuit should be free of any particles, debris and pollution.
Automatic air purging of the heat exchanger
The De-Air sequence is a safety function starting at every power ON and is used to remove the air from the heat-
exchanger. The De-Air sequence does not start after a general reset (such as the locking error reset or 24 hours
reset)
The display will show ‘dAir’ indicating that the controller is performing the De-Air sequence to purge the heat
exchanger of air, by sequencing the water heater pump OFF and ON. The
installer/technician
can cancel the De-
Air sequence by pressing a specific key-button combination from the display. By default, “De-Air” sequence takes
around 14 minutes.
• 1st cycle: The 3 ways valve moves to CH position and the general pump is activated for 10 seconds, deactivated
for 10 seconds, activated again for 10 seconds and then deactivated again for 10 seconds (DAir_Repetition_On-
Off, which means ON/OFF/ON/OFF each time for 10 seconds = 40 seconds in total).
• 2nd cycle: it starts when 1st cycle is ended. The 3 ways valve is moved to DHW position and repeats the same
cycling of the pump (DAir_Repetition_OnOff, which means ON/OFF/ON/OFF each time for 10 seconds = 40 sec-
ond in total).
This sequence (1st 2nd cycles) is performed DAir_Number_Cycles times (if DAir_Number_Cycles is 10
‘De-air’ sequence lasts (10 x 40) x 2 = 800 seconds).
During De-Air sequence
no heating or hot water demand will be served.
When the water pressure is too low, or pressure sensor is in error, the De-Air sequence will be suspended until
water pressure / sensor pressure is stable again. In that case the De-Air sequence will last longer than the esti-
mated 14 minutes.
The following scheme below shows the behavior of the 3-way valve and water heater pump during one whole
cycle of De-Air sequence with a DAir_Repetition_OnOff set to 2.