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Instructions on commissioning, maintenance, and troubleshooting for auroSTOR 0020111119_02
Fault Cause
Remedy
Primary heating is not working. The gas-
fired wall-hung boiler runs for a short
time, goes off, and then comes back on
again. This is repeated until the cylinder
is at its target temperature.
1. Air in the primary heating heat
exchanger.
Vent the primary heating heat exchanger.
2. Heat exchanger surface area too
small.
Compare the specifications of the boiler manufac-
turer with those of the cylinder manufacturer. It may
be possible to solve the problem by setting a higher
flow temperature on the gas-fired wall-hung boiler.
Only cold or lukewarm water comes out
of the draw-off points.
1. The cold and hot water draw offs on
the cylinder have been mixed up.
Turn off the cold water supply, then let water flow out
via the hot water draw off. Only a few litres of water
flow out if the connection is set up correctly. The hot
water withdrawal pipe intake is then in the air space
and further draining is not possible. If it is possible to
empty the entire cylinder via the hot water draw off,
the connections have been laid incorrectly. Change
the connections!
2. Hot water thermostat mixer set too
low.
Increase the setting.
3. Solar heating insufficient; gas-fired
wall-hung boiler does not reheat.
External control device faulty.
Air in the primary heating heat
exchanger.
Cylinder sensor faulty.
Check whether the gas-fired wall-hung boiler is work-
ing.
Check whether the external control device is working.
Check that the two port valve is in the DHW position.
Replace the two port valve.
Vent the primary heating heat exchanger.
Check the thermal cut-out and repair the fault.
Replace the cylinder thermostat.
Water flows out of the expansion relief
valve (only when heating up).
Dirt on the valve seat of the expansion
relief valve.
Check the seat of the expansion relief valve and
repair the fault.
Pressure reducing valve faulty.
If water only escapes during heating, switch off the
gas-fired wall-hung boiler and electric immersion
heater and check whether the pressure behind the
pressure reducing valve is lower than 3.0 bar. If so,
replace the pressure reducing valve.
Expansion vessel faulty.
Check the pressure in the expansion vessel. If the
pressure is insufficient, re-establish the pressure and
check whether the expansion vessel maintains it.
Expansion relief valve faulty.
If the pressure is normal, replace the expansion relief
valve.
Water flows out of the temperature and
pressure relief valve (only when heating
up).
Dirt on the valve seat of the tempera-
ture and pressure relief valve.
Check the seat of the temperature and pressure relief
valve and repair the fault.
The temperature control system for
the gas-fired wall-hung boiler is faulty.
If water is only escaping when being heated up by
the gas-fired wall-hung boiler, check the temperature
control system of the gas-fired wall-hung boiler.
Check whether the two port valve switches to the
heating position when the cylinder temperature is
reached.
Cylinder sensor faulty.
Check the cylinder sensor and corresponding thermal
cut-out, replace the cylinder sensor if necessary, and
repair the thermal cut-out fault.
Two port valve faulty.
Check the function of the two port valve and replace
if necessary.
Temperature and pressure relief valve
faulty.
If water is only escaping when being heated up by the
electric immersion heater, replace the temperature
and pressure relief valve.
Electric immersion heater faulty.
Check the temperature sensor of the electric immer-
sion heater and the corresponding thermal cut-out
and replace the electric immersion heater if necessary.
Only connection wiring diagram 6: The
thermal cut-out for the primary heating
circuit actuated at 80 ºC, thus causing
the two port motorised valve to close the
flow line to the cylinder.
The cylinder has been overheated by
the solar circuit.
Set the maximum cylinder temperature (MAXT 1) on
the VRS 560/2 solar controller to a maximum of
75ºC.
Use the fuses to deenergise the cylinder thermostat.
Unscrew the cover cap of the reset button for the
thermal cut-out (TCO) for the primary heating circuit.
Press the primary heating circuit TCO button to
repair the TCO fault. Mount the cover cap. Switch on
the cylinder thermostat using the fuses.
Table 9.1 Troubleshooting (continued)
9 Fault finding
