Problem Solving - Xylem CWM18-H3 Installation, Operating & Safety Instructions

PROBLEM SOLVING

PROBLEM
Water not hot enough
Water too hot
Water discharges continuously
through temperature/pressure
relief valve
Hot water flows back into cold
water line
Immersion heater does not
operate
POSSIBLE CAUSE
Coil inlet temperature too low
Air lock(s) in engine cooling
circuit
Top of storage heater above
engine cooling header tank
Thermostat in engine cooling
circuit not adjusted correctly
Thermo-syphon in coil circuit
when engine is not running
Engine cooling circuit water too
hot
Immersion heater control
thermostat set too high
Immersion heater control
thermostat has failed
Pump pressure switch cut-out
setting is higher than relief valve
setting.
Pressure switch has failed
Stored water too hot
Immersion heater control
thermostat set too high or has
failed.
Temperature/pressure relief
valve has failed
Thermal expansion
Electric supply failure
Control thermostat temperature
set too low.
High temperature cut-out has
operated
17
ACTION
Check coil inlet water
temperature and correct if
necessary
Check for air locks
Raise header tank
Check setting on thermostat
Contact your supplier for advice
Fit thermostat CW276A or
blender valve CW268 OR
CW272B
Adjust immersion heater control
thermostat
Check control thermostat.
Do not reset high temperature
cut-out until the cause of the
overheating has been
established
Check cut-out setting. Adjust or
replace switch, or fit pressure-
reducing valve
Replace pressure switch
Fit thermostat CW276A
Adjust or replace control and
high temp. thermostats
Replace temperature/pressure
relief valve
Fit non-return valve and
expansion tank, as outlined in
these instructions
Restore electric supply.
Check control thermostat and
correct if necessary.
Check control thermostat and
replace if necessary.
Inspect system before using
heater again.
Check that high temperature
cut-out setting is above control
thermostat setting: reset at 90ºC