Pump is overheated, but no heat transfer from col-
lector to the store, feed flow and return flow are
equally warm, perhaps also bubble in the lines.
Air in the system ?
no
yes
Is the collector circuit
plugged at the dirt trap?
yes
Pump starts up very late and stops working soon.
Switch-on-temperature
difference
∆Ton
too
large?
no
yes
Collector sensor unfa-
vourable placed (e.g.
contact sensor instead
of
immersion
sleeve
sensor?
yes
Bleed the system; the
primary pressure of the
expansion tank has to
exceed the static pres-
sure by approx. 0,5
bar, the system pres-
sure has to exceed it
by approx. 0,5 up to 1
bar (depending on the
dimensioning of the ex-
pansion tank); switch
the pump on and off for
a short time.
Clean the dirt trap
Change ∆Ton and ∆Toff
accordingly.
If
necessary
activate
tube collector function.
o.k.
Pump starts for a short moment, switches-off, switch-
es-on again, etc.
Is the temperature dif-
ference at the control-
ler too small?
no
yes
Wrong placing of the
collector sensor?
no
yes
Plausibility control of
the option tube collec-
tor special function?
The temperature difference between store and col-
lector increases enormously during operation; the
collector circuit cannot dissipate the heat.
Collector circuit pump
defect ?
no
yes
Heat exchanger calci-
fied?
no
yes
Heat exchanger
plugged?
no
yes
Heat exchanger too
small?
yes
GB
Change ∆Ton and ∆Toff
accordingly.
o.k.
no
Mount the collector sen-
sor at solar feed flow
(warmest collector out-
put); use the immersion
sleeve of the respective
collector.
Control / replace
Decalcification
Clean
New calculation of the
dimension.
59