STIEBEL ELTRON SOM 10 - Manual (Page 77)

77
en
Pump is overheated, but no heat transfer from the collector to the store, flow
and return have the same temperature; perhaps also bubbling in the lines.
Air or gas bubbles in the system?
no yes
Is the collector circuit blocked at
the dirt trap?
yes
Clean dirt trap
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.
no
no OK
Pump starts up very late.
The temperature diffrence between store and collector increases enormously
during operation; the collector circuit cannot dissipate the heat.
Collector circuit pump defec-
tive?
no yes
Heat exchanger calcified?
yes
Check / replace it
Decalcify it
no
Heat exchanger blocked?
yes no
Clean it
Heat exchanger too small?
yes
Change ∆Ton and ∆Toff
correspondingly.
Switch-on temperature diffe-
rence ∆Ton too large?
no yes
Vent the system; increase the
system pressure to a static
primary pressure of at least
plus 0.5 bar (7.25 psi); if ne-
cessary continue to increase
pressure; switch the pump
off and on for a short time.
Plausibility control of
the option evacuated
tube collector special
function
Mount the collector sensor at
solar flow (warmest collector
output); use immersion sleeve
of the respective collector.
Replace with correctly
sized one.
Non-ideal position of the
collector sensor (e.g. flatscrew
sensor instead of sensor in
immersion sleeves).
yes
Activate evacuated tube
collector function if neces-
sary.
o.k.