5.Control system - Meibes

9. Trouble-shooting
The following is to be checked if the domestic hot water
temperature is not reached:
■ System voltage (fuses)
■ Buffer temperature
■ Vent the freshwater station
■ A temperature sensor interruption or a short circuit
is displayed in the information menu by a flashing
general error message and is shown individually
when requesting each sensor.
■ Carry out characteristic curve calibration, from
point 6.3.2.
■ Carry out a circulation adjustment, point 6.3.3.
■ During a hot water withdrawal, the circulation pipe
becomes cold.
Cause: The return flow preventer in the connecting
nipple above the circulation pump can start leaking
due to soiling in the cold water network.
■ Flow rate metre: To check this, a hot water tapping
is required and the flow in litres per minute read in
the information menu. An intact flow rate metre
should show a relatively constant value. Should
fluctuations occur, check whether this comes from
the domestic water network, for example in pressure
increase systems
■ Set the freshwater station according to the system
examples.
■ The pumps P1 and P2 run alternatively and the status
display in the information menu switches between
active 50, after-run and off.
■ Carry out a circulation adjustment, point 6.3.3.
■ After several months of smooth running operation
the hot water capacity is no longer reached.
■ If a dirt filter has been installed in front of the
station, this should be cleaned.
■ Check return flow preventer.
■ Vent the buffer and the freshwater station
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■ A short time after drawing off hot water at the tap
(e.g.: washbasin) the hot water temperature drops
sharply even though the control system displays
e.g.: 50°C hot water temperature.
■ The return flow preventer should be checked in
the connecting nipple above the circulation pump
to see if it leaks as a result of soiling in the cold
water system and if cold water has been
pressed into the circulation piping.
■ The circulation does not work:
■ Carry out circulation adjustment!
■ Check time slot!
■ The temperature of the heat transfer media
in the buffer is too low.
The circulation set temperature + 2 K is not
being reached at T2 or at T5, if present.
(see point 5.3.5 Circulation)
Please ensure that there is a sufficient quantity
of heat in the buffer!
With option T5 „reheat buffer“, a type of boiler
can be activated.