KEY RK-2001W2N, Operation Manual, Page: 8 / 16

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The work mode and pause time of CH pump [Pc 2] - in STOP mode or when the
room thermostat circuit is not shorted, CO pump is turned on for 30 seconds to move
water in the heating system. This parameter controls the repeat time. Setting this
parameter to „--” turns this function off. In case of some heating systems the pump
should work independently of room thermostat. In such case the parameter should be
set to value „F”.
5.3. Preparation of hot tap water
The hot water tank temperature [u 50] – temperature value which will be kept in the
hot water tank.
The heating hysteresis of the hot water tank [uh 5] – valve which the temperature
in the tank has to decrease by so that the hot water pump turnes on in order to heat up
the water in the tank.
Work mode of hot water pum [ur 0]
the [ur 0] value indicates no sensor or hot water pump. The sensor is not taken
into account in testing failures, i.e. it can remain unconnected and in the user
parameter menu there is only the desired boiler thermostat temperature
displayed.
[ur 1] value - hot water pump working with priority
[ur 2] value - hot water tank working without priority
[ur 3] value - means controlling of the returning water mixing pump in the
boiler with the launch temperature of [u 50] and hysteresis [uh 5].
5.4. Boiler work temperature setting.
Minimum boiler temperature [L 45] - minimum temperature which you can set with
the boiler thermostat knob.
Maximum boiler temperature [H 85] - maximum temperature which you can set with
the boiler thermostat knob.
Boiler temperature hysteresis [h 2] - this parameter defines what value should
temperature of water in the boiler decrease by, below temperature set with the
thermostat knob so that the fan turns on.
5.5. Boiler overheating protection.
Boiler overheating temperature [A 99] - value, exceeding which causes permanent
turn off of the fan to prevent boiler overheating. After the temperature increases above
80°C the central heating pump is turned on to cool down the boiler. Overheating mode
is indicated by displaying error [E 2] on the display. It can be turned off by pressing
STOP button, but only when temperature decreases below this temperature. Fan turn
off also occurs in case of damage of the boiler temperature sensor which is displayed
on the display with error [E 1].