66
en-US/C
A
Air or gas bubbles in the system?
Switch-on temperature difference
∆
Ton too
large?
Collector circuit pump / valve defective?
Heat exchanger calcified?
Heat exchanger blocked?
Heat exchanger too small?
Temperature difference at the controller too
small?
Are valves or
non-return valves
defective?
Plausibility con-
trol of the evacu-
ated evacuated
tube collector and
antifreeze function
Minimum limitation
active
Mount the collec-
tor sensor at solar
flow (warmest col-
lector output); use
immersion sleeve
of the respective
collector.
Activate evacuated
tube collector func-
tion if necessary.
Wrong position of the col-
lector sensor?
Non-ideal position of the collector sensor (e.g.
flatscrew sensor instead of sensor in immersion
sleeves)?
Replace
Vent the system;
increase the system
pressure to a static
primary pressure of
at least plus 0,5 bar;
if necessary continue
to increase pressure;
switch the pump off
and on for a short
time.
Change
∆
Ton and
∆
Toff correspondingly.
Check / if necessary, replace
Decalcify it
Clean it
Replace with correctly sized one.
Change
∆
Ton and
∆
Toff
correspondingly.
no
no
no
no
no
no
no
no
no
yes
yes
yes
yes
yes
yes
yes
o.k.
o.k.
yes
yes
yes
Pump is overheated, but no heat transfer from
the collector to the tank, flow and return have
the same temperature; perhaps also bubbling in
the lines.
Pump starts up very late.
The temperature difference between tank and col-
lector increases enormously during operation; the
collector circuit cannot dissipate the heat.
Pump starts for a short moment, switches off,
switches on again, etc.
9.1
Miscellaneous
Summary of Contents for SCU345
Page 71: ...en US CA 71 Notes ...
