Download Viessmann SCU224 Technical data

SCU224
5.1Various:
Pump is overheated, but no heat is being transferred from
collector to the tank, feed flow and return flow are equally
warm, possibly also bubble in the tubes
Pump starts for a short moment, switches-on/off
repeatedly
Air in the system?
Is the temperature difference at the controller
too small?
no
yes
Exhaust the system; increase system pressure to
the minimum pressures
listed in the Vitosol Startup and service manual.
Switch the pump on and
off for a short time
Is the collector circuit
blocked at the dirt trap?
no
Wrong placing of the
collector sensor?
no
yes
Clean the dirt trap
yes
yes
Activate option tube collector special function
Change ∆T on and ∆T off
accordingly.
no
o.k.
Mount the collector sensor at solar feed flow
(warmest collector output); use the sensor well of
the respective ­collector.
Pump starts up very late and stops working soon.
The temperature difference between tank and collector
increases enormously during operation; the collector circuit cannot dissipate the heat.
Switch-on-temperature
difference ∆Ton too
large?
Collector circuit pump
defect ?
no
yes
no
Change ∆T on and ∆Toff
accordingly.
Repair / Replace
Heat exchanger calcified?
Collector sensor un­favour­
able placed (e.g. contact
sensor instead of sensor
well.
yes
yes
no
yes
Decalification
If necessary activate tube
collector function.
o.k.
Heat exchanger plugged?
no
yes
Heat exchanger too
small?
yes
New calculation of the
dimension.
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