21
5.1 Various
Pump starts for a short moment, switches off, switches on
again, etc.
Temperature difference at
the controller too small?
no
yes
Wrong position of collector
sensors?
yes
Change
∆
Ton and
∆
Toff
correspondingly. Problem
solved?
Mount the collector sensor
at solar flow (warmest
collector output); use
s e n s o r w e l l o f t h e
respective collector.
Pump starts up very late
The temperature difference between tank and collector
increases enormously during operation; the collector circuit
cannot dissipate the heat.
Collector circuit pump
defective?
no
yes
Heat exchanger calcified?
yes
Check / replace it
Decalcify it
no
Heat exchanger blocked?
yes
no
Clean it
Heat exchanger too small?
yes
Replace with correctly
sized one.
no
Plausibility control of
the option tube collector
special function
Change
∆
Ton and
∆
Toff
correspondingly.
Switch-on temperature
difference Ton to large?
no
yes
Non-ideal position of the
collector sensor (e.g. flatscrew
sensor instead of sensor in
sensor wells)?
no
Pump is overheated, but no heat transfer from the collector
to the tank, flow and return have the same temperature;
perhaps also air / gas bubbles in the lines.
Air in the system; in crease
the system pressure to at
least static primary pres-
sure plus 7. 25 psi (0.5 bar);
if necessary continue to
increase pressure; switch
the pump off and on for a
short time.
Air in the system?
no
yes
Is the collector circuit
blocked at the dirt trap?
yes
Clean the dirt trap
Activate tube collector
function if necessary.
yes
o.k.
yes
o.k.
