SECTION 7
-
The HIU Controller first power up and set up
Page 19
SECTION 10
-
Fault and Error Codes / Fault finding guide
NO
YES
NO
YES
If the flow is reduced at a hot water outlet does
the DHW temperature begin to rise?
Does the tap symbol show
on the display when calling
for hot water?
Check the cable and connections to
the flow sensor, is it connected?
Has this solved the problem?
YES
Isolate and drain down the HIU.
Then remove and clean the primary strainer.
Replace and fill. Check operation again.
Has hot water delivery now been restored?
Check for blockage, check PHE for blockage.
YES
Is a warning symbol displayed
on the controller screen?
NO HOT WATER
(but heating is working)
Read the Heat Meter reading for M
3
/hr flow rate
and check primary flow temperature. Look up the
HIU performance table.
Is the HIU Flow reading below what is required to
produce hot water?
The problem lies in the supply to the HIU.
Not sufficient FLOW or TEMPERATURE.
Investigate and resolve.
NO
NO
Check Bypass is closed.
Problem solved?
Hot Water
at the taps!
See fault code description* and
check the correct parameters are set,
rectify. Or if it is a fault, then check the
component is connected or possibly
faulty. Rectify the fault
* Have the
‘
Controller Programming Guide
at hand!
NO
YES
NO
Check primary
flow rate, is it
sufficient?
Blockage
cleared.
YES
06/21 E&OE
