MHG Heating ThermSelect, Assembly, Commissioning And Maintenance Instructions

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ThermSelect®
9. Troubleshooting
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9 Troubleshooting
9.1 Troubleshooting
It is frequently noticeable that the heat pump heating systems are
not operating properly because the heating circuit does not have the
required volume flow. The consequence of this is the activation of
safety devices on the heat pump.
In case of insufficient or no flow in the heat exchange on the heating
circuit side, this leads to a high-pressure disruption. It cannot be
ruled out that the safety temperature limiter will also switch the sys-
tem off with insufficient hot water flow.
The causes of the listed faults have their origin in the periphery and
in the rarest cases, in the heat pump itself. Incorrect settings on the
controller can have similar effects. The activation of relevant sen-
sors and the signalisation of a fault are for the protection of the sys-
tem and are generally not an indication of a defective heat pump.
Faults and their removal
If the heat transfer is suddenly disrupted when the heat pump is
running (e.g. due to standstill of circulating heat pump or closed
valves), it can (due to the thermal inertia of the system) occur that
the high-pressure safety limit switch in the heat pump is activated.
The heat pump is thereby shut off and an automatic restart is pre-
vented for safety reasons.
NOTE!
Reduction of the service life of the high-pressure -
safety limit switch, as well as the compressor,
through excess wear and tear.
Therefore:
-
If the high-pressure limit switch is activated, check
and rectify the cause.
Another possible reason for triggering this high pressure safety limi-
ter may also be related to the local conditions of the heat pump's in-
stallation site which may necessitate the installation of an oil sump
heater (strip heater on the condenser) or a "pump-down function".
Course of action for malfunctions
If electrical errors (e.g. defective sensors) can be ruled out, begin
with checking the circulation pump and valves of the heating system
and heat source.
NOTE!
If all errors can be ruled out on the external system,
the cooling cycle of the heat pump must be checked
by an authorized technician.