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Trouble Shooting – continued:
No Secondary Flow:
Possible Causes:
a) Electrical Fault
b) Pump Tripped (Trip Lamp illuminated on control panel)
c) High Limit Shut Down (High Temp. Lamp illuminated on control panel facia)
d) Air Lock in system
e) Not in correct mode of operation.
Remedies:
a) Check electrical supply to control panel together with the mcbs fitted within the panel
b) Reset overload within the control panel using the blue reset button fitted on the relevant
overload F112 is for primary pump 1
F132 is for primary pump 2 (only if fitted)
F152 is for secondary pump 1 (only if fitted)
F172 is for secondary pump 2 (only if fitted)
Should the pump fail to restart, a problem may exist elsewhere in the system and advice
should be sought from the installer/supplier. For a twin headed pump, switch the control
dial to “manual” – this changes over the pump head that is currently in operation.
c) The system will need to be reset after high limit shut down. Wait for a few minutes to allow
the temperature to cool slightly and then press the manual re-set button. Should the
problem fail to reset or frequently reoccur, advice should be sought from the
installer/supplier.
d) Vent air from system.
e) Check Main Control Switch/Time clock.
Secondary Water Temperature too High / Low , or unit cuts out on over heat
Possible Causes:-
a) Wrong set point on controller.
b) Air Lock in pipe work.
c) Primary water temperature too high or too low.
d) Primary water flow too high / too low, or secondary flow not correct.
e) Fault in temperature sensor.
f) Actuator fault – the valve does not modulate, or move during operation..
g) Control valve seized or binding
h) Primary circuit pressure feeding PHE too high
Remedies:-
a) Adjust Controller – see relevant section in manual
b) Vent System
c) Ensure that boiler or source of primary temperature water is functioning correctly & rectify
as required.
d) Ensure that primary and/or secondary water pump(s) / source is / are performing correctly
& rectify as required.
e) Electrician required – the sensor and the wires need to be checked. Isolate panel, then
disconnect the temperature sensor wires (not the over heat stat) out of the panel and
measure the resistance. The resistance should be around 110 ohms (depending on
temperature. If a reading of “infinite” is shown then there is an open circuit, and the most
likely cause is that the wires leading to and from the sensor are broken. If the reading is
zero, then there is a short circuit in the circuit. Check / replace the wires/sensor.
f) Actuator failed – remove from valve (see actuator replacement section). Alter set point to
low temperature and check to see if actuator drive turns to fully closed position, and then
alter set point to a high temperature and check to see if drive rotates a full 90 degrees
from fully closed position. If no, or in-sufficient travel of the drive is observed, then
actuator requires replacement.
