Xylem EPR IM Electric heater-circulator unit EPR (obsolete) - Manual (Page 29)

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Instruction manual Laing Electric heater circulator unit
www.lainginc.com
feed line temperature via the constant temperature setting. During the whole
starting operation the system has to be controlled and the water which is
diminished by the release of the gases has to be replaced and the gases
have to be vented.
If this advice is not followed, there is the danger that the air accumulates in
the pump and interrupts the circulation of the pump. In this case the bearing
can also be damaged.
Replacement of the circulation pump
In case it is necessary to open or replace the circulator of the Electric heater-
circulator, the Electric heater-circulator has to be separated from the grid and
the water has to be drained.
If the Laing Compact station is used, the return line valves of all heating
loops have to be closed and a hose has to be attached to the lower KFE
tap. After opening the KFE tap about 0.9 to 1.8 Gallons of water will be
discharged.
Now the pump has to be taken off by unscrewing the two fastening screws.
When the pump is removed it should not be tilted too much since otherwise the
rotor might fall out and could be damaged. After the pump has been removed
the rotor can be drawn off upwards and can be tested for dirt of scaling.
In replacing the pump the rotor has to be replaced before the seal ring other-
wise there could be damage. Before the Electric heater-circulator is started
again the air has to be vented in any case.
Replacement of the safety temperature limiter STBR
To replace the switching module of the safety temperature limiter the leads
of the safety temperature limiter have to be marked and than disconnected.
Thereafter, the switching module has to be removed by unscrewing the nut
around the reset knob Z at the outside of the control box . Then the capillary
has to be carefully removed from the immersion shell. One has to take into
account that the temperature sensors are also contained in the immersion
shell.
Afterwards, the temperature sensors have to be removed from the old
capillary and be attached to the new capillary in the same position directly
above the thick area of the capillary. This point is very important since an
improper mounting can lead to a malfunction of the control.
Then the capillary has to be carefully replaced into the immersion shell