Vaillant Solar System and auroSTOR unvented solar cylinder Start-Up, Maintenance And Troubleshooting Manual page 56

Malfunction
Pump starts up and goes off shortly
afterwards.This is repeated several times
until the system runs its course. The same
occurs in the evening.
The pump is making noises.
Solar system
Clocking of the system.
The pressure gauge indicates a drop in
pressure.
The water pressure and amount of
discharged water decreases at hot water
taps.
The system is making noises. Normal in the
first few days after filling the system.
If it occurs later, there are two possible
causes:
The solar gain is unusually low.
Solar control
auroMATIC 560: display example "KOL 1 Err"
or similar
Solar cylinder
The cylinder cools down at night.
The flow and return temperatures vary after
switching off the pump. The collector
temperature is higher than the air
temperature at night.
Table 8.1 Troubleshooting (continuation)
Manual - Solar hot water systems 0020009607_02
Cause
The temperature difference of the controller
is too low or the pump speed is set too high.
The solar radiation is not yet sufficient to
heat up the entire pipework.
1. Air in the pump
2. Insufficient system pressure.
Incorrect position of the collector sensor
A drop in pressure is normal shortly after
filling the system, since air still escapes from
the system.If a pressure drop occurs again
later on, the cause may be an air bubble,
which has been subsequently released.
Furthermore there are fluctuations to the
pressure in normal operation mode between
0.2 to 0.3 bar, depending on the system
temperature. If the pressure drops
continuously, there is a leak in the solar
circuit, in particular in the collector array.
Pressure in the main cold water supply too
low.
Line strainer in the pressure limiting valve
dirty.
Pressure limiting valve defective.
Blockage in the system.
1. The system pressure is too low. The pump
is drawing air via the bleeder.
2. Pump power set too high.
The pipe insulation is too thin or incorrect.
The system may have been designed
incorrectly.
Defective sensor (short circuit or
interruption).
1. The gravity brake is blocked.
2. One-pipe circulation in the event of short
pipe networks with low pressure loss.
Troubleshooting 8
Remedy
Check whether the entire pipework is fully
insulated.Increase the temperature
difference of the controller.
Bleed the pump.
Increase the system pressure.
Position the collector sensor in the flow.
Insulate the collector sensor.
First check all screw connections, stuffing
boxes at gate valves and threaded
connections, then the soldering points.
Check the collector array and replace a tube
or the collector if necessary.
Inform the owner and notify the water
supply company.
Clean the line strainer in the pressure
limiting valve and replace it if necessary.
Replace the pressure limiting valve.
Unblock the blockage and replace any
blocked parts.
Check the system for water leaks at the
expansion relief valve and temperature/
pressure limiting valve.
Increase the system pressure.
Switch to a lower speed.
Check the insulation. Check the layout of the
system (collector size, shading, pipe lengths)
and modify the system if necessary.
1. Check the cable connection.
2. Measure the resistance values of the
disconnected sensor at known
temperatures, and compare these with the
manufacturer's specifications.
3. Inspection of the piping for damage.
1. Check the position of the blue handle.
2. Check the gravity brake for tightness
(jammed cuttings, particles of dirt in the
sealing face).
3. Do not connect the solar heat exchanger
directly, rather pull the supply pipes
downwards and then upwards to the
collector (syphon supports the gravity
brake) or install a 2-port valve, which is
switched on at the same time as the pump.
Install a gravity brake (as close as possible
to the cylinder).
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