oventrop Uni LH Mode D'emploi page 8

Replacement of the gland nut
Remove thermostat from the valve. Unscrew the gland nut
with a 14 mm key. Water will not escape as the valve is
provided with an additional seal. Screw on new gland nut
(item no. 1017501) and tighten with key. Replace the
thermostat.
Note:
Not for valves "A (as from 2013), AV9, ADV9, CV9, RFV9,
E, AQ, RFQ, EQ, and RF (as from 2014)".
Disposal
To protect the sensor liqiud from escaping, the thermost-
at must not be destroyed when disposed of.
The thermostat contains hazardous waste
Dismounted/defective thermostats can be returned to the
manufacturer Oventrop.
They will be disposed of professionally.
Check list for faults
The desired room temperature is not reached or maintained:
11. The flow temperature is set too low.
12. The circulation pump is not switched on.
13. The circulation pump or the flow temperature is con-
trolled by a separate electric room thermostat.
14. The pump output is set too low.
15. The flow direction of the pump is reversed.
16. The heating pipe is throttled back or shut off.
17. With gravity fed heating systems, a circulation pump
must be installed subsequently if necessary. Gravity
systems are very sensitive to the presence of air in the
system.
18. The radiator is covered by curtains, panelling etc. Use
a thermostat with remote sensor.
19. Temperature at the thermostat differs widely from the
ambient temperature due to poor siting. Use a ther-
mostat with remote sensor.
10. The remote sensor is badly sited. The best height is
about 1 m above the floor level.
11. The radiator selected is too small for the size of the
room.
12. If the required temperature is only reached at a
higher setting of the thermostat, recalibrate the ther-
mostat (if desired).
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8
Gland nut
The thermostatic radiator valve does not function:
13. The thermostat is not screwed tightly onto the valve.
14. The capillary of the remote sensor or the remote con-
trol was kinked or flattened. Use a new thermostat and
install carefully.
15. If a strainer is used, has it become blocked? Remo-
ve valve, flush pipe thoroughly, clean strainer and re-
install.
16. Air is reducing circulation in the radiator. Vent the ra-
diator.
17. Air is interfering with circulation in the heating system.
Fit an automatic airvent in a suitable position.
18. The valve seat was distorted, e.g. as a result of im-
proper assembly in vice. Fit a new valve.
19. The thermostat was readjusted due to unauthorised
tampering. Recalibrate thermostat (see page 7).
The valve cannot be shut off:
20. In most cases this is due to dirt particles on the val-
ve disc, e.g. welding beads or rust particles. These
particles can often be removed by repeatedly working
the valve stem. To do this, the thermostat must be
removed first. The valve insert must be replaced if the
valve disc was damaged. The valve insert can be
replaced without draining the system with the help of
the "Demo-Bloc" tool specially developed for this pur-
pose. If this is not successful, the valve insert must
be removed after having drained the system and the
residue has to be removed from the valve or the val-
ve has to be replaced.
21. The frost protection responds. The crystal symbol
corresponds to a room temperature of about 7 °C. The
valve will therefore open as soon as the temperatu-
re drops below this level, e.g. when ventilating the
room.
22. The thermostat is defective and must be replaced. First
test whether this is due to dirt or unauthorised tam-
pering of the calibration. Screw on a new thermost-
at and send the old one back to the supplier for re-
placement. If still under guarantee, it will be repaired
or replaced free of charge.
The valve leaks:
23. The gland nut is loose. Tighten it.
24. The O-ring seal of the gland nut is damaged. Repla-
ce the gland nut. The system does not have to be drai-
ned to do this (see above).
25. The valve insert is loose. Tighten. If necessary, use a
new insert (compare point 20).
The valve rattles:
26. Supply and return pipe are reversed.
Flow noises occur:
27. Can the pump head (differential pressure) be redu-
ced?
Please contact the manufacturer in case of further que-
stions.
Subject to technical
modification without notice.
Printed on paper
free from chlorine
bleaching.