Control Valve Fault Indication; Action Of Control Valve During An Error; Control Valve Calibration; Circulating Pump Fault Indication - Bosch Worcester Greenstar HIU E Installation And Maintenance Instructions Manual

Fault finding and diagnostics
9.4

Control valve fault indication

The modulating control valves for CH and DHW have three indicators on
the head of the actuator to denote operational states, see figure 7,
Designation of components, items [4] and [5] to locate the valves.
The case, insulation and control box will need to be removed to gain
access to the control valve indicators.
There are three symbols on the head of the valve actuator, behind these
symbols are coloured indicators that are used to indicate the error
situation. The table below gives details of the coloured indicators and
their meaning:
Indicators ON Reason/Problem
Green flashing Valve is stuck completely open
Green and blue Valve is stuck between 60 and 99.9% open
flashing
Blue flashing Valve is stuck between 40 and 60% open
Blue and Orange Valve is stuck between 0.1 and 40% open
flashing
Orange flashing Valve is stuck completely closed
Green and The input signal is fault and the valve is completely
Orange closed
Green, Blue and Faulty valve
Orange flashing
Table 35 Control valve fault indication
Fig. 78 Control Valve indicators
[1] Circle - Green
[2] Square - Blue
[3] Triangle - Orange
9.4.1

Action of control valve during an error

When an error occurs, there will be a recovery attempt made by the
control unit. The valve will back off from its stuck position and then try to
push through the blockage in order to reach its set point position. This
recovery attempt will last approximately 0.5 seconds.
If this is successful, the error will reset.
If it is not successful, then an error signal is sent from the control valve to
the control unit and the control valve will try to move to its closed
position. If the control valve reaches its closed position but is still in
error, an error signal is still sent to the control unit. The error will be
indicated on the HIU control unit,  9.3.
62
1
2
3
9.4.2

Control valve calibration

The control valve can be calibrated by:
▶ Manually set the rotary switch for the control valve on the control unit
to the calibration position, (
The control valve will enter its calibration process below:
• Valve moves to fully closed position.
• Valve moves to fully open position
• Valve moves back to normal operation.
If the control valve has finished its calibration process but is still in
calibration mode, the valve will move to fully open position and remains
there for 10 minutes, or until calibration mode is exited:
▶ Manually setting the rotary switch for the control valve on the control
unit to the required set point.
9.5

Circulating pump fault indication

If the circulating pump has detected one or more errors, the bi-coloured
LED 1 switches from green to red. When an error is active, the LEDs
indicate the error type as shown in table. If multiple errors are active at
the same time, the LEDs only show the error with the highest priority.
The priority is defined by the sequence of the table.
When there is no active error anymore, the user interface switches back
to operation mode.
Fig. 79 Circulating pump fault indication
[1] LED indicators
Display Indication Pump operation Counter action
One red LED + Rotor is Trying to start
one yellow LED blocked. again every 1.33
(LED 5) seconds.
One red LED + Supply Only warning,
one yellow LED voltage too pump runs.
(LED 4) low.
One red LED + Electrical Pump is stopped
one yellow LED error. because of low
(LED 3) supply voltage or
serious failure.
Table 36 Circulating pump fault indication
).
1
1
2
3
4
5
Wait or unblock the
shaft.
Control the supply
voltage.
Control the supply
voltage/replace the
pump
6 720 808 928 (2017/06)