Bosch Worcester AGS 5 - Page 22

FAULT FINDING
6 720 643 603 (2011/11)
22
Temperature differences in solar heating circuit are too high / flow temperature is too high / high collector
temperature reached too quickly
Solar yield too low
or system damage.
Faulty temperature sensor or controller
malfunction.
Check temperature sensor and settings of
controller.
Air in the system. Bleed or purge the system.
Volumetric flow rate too low.
Check/adjust the flow rate.
Blocked line.
Check/purge the pipelines.
Collector arrays not hydraulically
balanced.
Carry out hydraulic balancing.
Pressure drop in the system.
Solar yield too low. Loss of heat transfer fluid at joints. Braze any leaks. Replace seals. Retighten
screw fittings.
Loss of heat transfer fluid through an
open safety valve.
Check inlet pressure and size of expansion
vessel.
Vapour has escaped through open air vent
(normal operating function).
Close air vent after venting.
Frost damage.
Check frost protection.
No flow noticeable on flow rate indicator despite pump running.
Solar yield too low. Shut-off fittings are closed. Open shut-off fittings.
Air in the system.
Bleed or purge the system.
Indicator element in the flow limiter is
sticking.
Clean the flow limiter.
Noises in the collector array at high levels of solar irradiation (vapour knocking).
Leakages in solar
heating circuit.
Balanced flow through the collector arrays
is not possible.
Check piping.
Expansion vessel too small or faulty.
Check design and inlet pressure of the
expansion vessel and check operating
pressure.
Pump power is too low. Check pump, replace if necessary.
The collector with the collector
temperature sensor is under shade.
Remove shade.
Air in the system.
Bleed or purge the system and check slope of
pipes.
Type of fault
Effect Possible causes Remedy
Tab. 11