74
Chapter 9
ELECTRONIC CONTROL UNIT
The pump is hot, but
there is no heat transfer
from the collector to
the tank; fl ow and
return same heat; some
bubbling in the pipes.
Air present in the system.
Deaerate the system.
System pressure too low.
Increase the system pressure by a
minimum of + 0.5 bar with respect to
the primary static pressure; continue
to increase it if necessary; insert and
disconnect the pump manually.
Collector circuit fi lter blocked
Clean the fi lter
The pump is inserted
late.
Diff erence of insertion temperature
Δ
Tins set too high.
Modify “
Δ
Tins and if necessary “
Δ
Tdis.
Collector probe positioned in not
optimal position.
Move the probe inside the collector.
The pump continues to
insert and disconnect
frequently.
Diff erence of insertion temperature
Δ
Tins set too low.
Modify “
Δ
Tins and if necessary “
Δ
Tdis.
Collector probe positioned in not
optimal position.
Move the probe inside the collector.
The temperature diff erence
between the tank and the
collector increases a lot;
the collector circuit does
not lead the heat away.
Collector circuit pump faulty.
Check the pump.
Presence of lime-scale on the heat
exchanger.
Remove the lime scale from the heat
exchanger.
Heat exchanger blocked.
Clean the heat exchanger
The tank cools down
during the night.
Collector circuit pump also functioning
at night. The temperature of the collector
is greater than the external temperature
during the night.
Check the OCR and ORAF functions.
Tank fi tting insulation insuffi
cient.
Increase insulation.
Tank fi tting insulation not adherent.
Change or increase the insulation.
Presence of domestic hot water
circulation circuit.
Use a timer for the circulation pump.
Install a non-return valve to prevent
natural circulation.
Presence of additional heating in the
storage tank.
Install a non-return valve in the
additional heating circuit.
Natural circulation could start
through additional heating.