SHR
521 20
© Dra
yton
06
334
SHR 521
20.monen.
ind
d
|
18
Pump starts for a short moment, switches off, switches on
again, etc. (“controller hunting“)
Is the temperature diffe-
rence at the controller
too small?
no
yes
Wrong position of the
collector sensor?
yes
Change
∆
T
on
and
∆
Toff
accordingly.
Mount the collector sen-
sor at solar feed flow
(warmest collector out-
put); use the immersion
sleeve of the respective
collector.
Pump starts up very late and soon stops working soon.
The temperature difference between store and collector
increases enormously during operation; the collector cir-
cuit cannot dissipate the heat.
Collector circuit pump
defect ?
no
yes
Heat exchanger calcified?
yes
Control / replace
Decalification
no
Heat exchanger blocked?
yes
no
Cleaning
Heat exchanger too
small?
yes
New calculation of the
dimension.
no
Check collector special
function.
Change
∆
T
on
and
∆
Toff
accordingly.
Switch-on temperature
difference
∆
T
on
too high?
no
yes
Collector sensor unfavour-
able placed (e.g. contact
sensor instead of immersion
sleeve sensor?
o.k.
no
Pump is overheated, there is no heat transfer from coll-
ector to the store, feed flow and return flow are equally
warm, perhaps also bubble in the lines.
Drain the system; increa-
se system pressure to at
least static primary pres-
sure plus 0,5 bar; if neces-
sary continue to increase,
switch the pump for a
short time off and on.
Air in the system?
no
yes
Is the collector circuit
blocked at the dirt trap?
yes
Clean the dirt trap
5.1Various:
If necessary activate tube
collector function.
yes
o.k.
