Xylem EPR IM Electric heater-circulator unit EPR (obsolete) - Manual (Page 30)

30
Instruction manual Laing Electric heater circulator unit
www.lainginc.com
until it touches the bottom. Thereafter, the safety temperature limiter has to be
secured by the nut and the leads have to be connected to the same positions
as before.
Replacement of the main circuit board EPRH
To replace the main circuit board the Electric heater-circulator has to be dis-
connected from the grid and thereafter, the cover from the terminal box has
to be removed.
Then two snap connectors M have to be disengaged by pressing with a screw
driver from above on the tongue of the connector (see page …). Thereafter
the circuit board can be pulled out. One has to take care that the leads that
are pinned to the circuit board will not get stuck. When the circuit board has
been moved up high enough, the leads can be removed.
Before the circuit board is reinserted, the plugs have to be fully inserted into
the board. One has to make sure that the slots in the circuit board fit into the
bars of the plugs.
Thereafter the circuit board is pushed downwards until the snap connectors
are in the right position and the board can be snapped in.
Important Notices
Important Notice: How to avoid noise problems
Since the Electric heater-circulator is often used in living quarters, it is es-
pecially important to avoid noise. In this respect it is very important that the
Electric heater-circulator and the connected pipes are always joined by rubber
isolatorsto avoid direct sound transmission. This applies also to pipes installed
inside the walls.
Important Notice: How to avoid overheating
To avoid overheating of the Electric heater-circulator it is obligatory that
during the heating cycle the Electric heater-circulator is continuously filled
with water. If the feed line or the return line will be shut off as for instance in
a floor heating system, in which all loops have a zone control, the optionally
available Laing Zone module with pump shut off has to be installed. This will
shut off the pump until a through flow is possible again. In heating systems
with radiators a relief valve has to be installed.
Important Notice: In the event of safety temperature limiter failure
When the safety temperature limiter will become very hot, as can be the case
when the Electric heater-circulator is switched on and off several times without
being filled with water, the safety temperature limiter will switch off once more