Resol BASIC controller Manual For The Specialised Craftsman page 38

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
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?
no yes
Plausibility control of the option
tube collector special function.
38
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 on and off
for a short time.
Clean dirt trap.
Change Ton and Toff correspond-
ingly.
o.k.
no
Mount the collector sensor at solar
flow (warmest collector output); use
immersion sleeve of the respective
collector.
Pump starts up very late.
Switch-on temperature difference
Ton too large?
no yes
Non-ideal position of the collector
sensor (e. g. flatscrew sensor instead
of sensor in immersion sleeves).
yes
The temperature difference between store and collector increases enormous-
ly during operation; the collector circuit cannot dissipate the heat.
Collector circuit pump defective?
no yes
Heat exchanger calcified?
no yes
Heat exchanger blocked?
no yes
Heat exchanger too small?
yes
Change Ton and Toff corre-
spondingly.
Activate tube collector function if
necessary.
o.k.
Check / replace it.
Decalcify it.
Clean it.
Replace with correctly sized one.