Glowworm Lighting 250 I - Manual (Page 21)

5 Fault Finding
Malfunction Cause Remedy
Water flows out of the expansion relief
valve (only when heating up).
Dirt on the valve seat of the expansion
relief valve.
Check the expansion relief valve and
reset it manually.
Pressure limiting valve defective. Switch off the boiler and immersion
heater and check whether the pressure
behind the pressure limiting valve is lower
than 3.0 bar if water flows out only when
heating up. If so, replace the pressure
limiting valve.
Expansion vessel defective. Check the pressure in the expansion
vessel. If the pressure is insufficient,
re-establish the pressure and check
whether the equalisation tank maintains
the pressure.
Expansion relief valve defective. If the pressure is normal, replace the
expansion relief valve.
Water comes out of the temperature and
pressure relief valve (only when heating
up).
Dirt on the valve seat of the temperature
and pressure relief valve.
Check the seat of the temperature
and pressure relief valve and reset it
manually.
Temperature control of the boiler
defective.
Check the temperature control of the
boiler if water only comes out when
reheating with the boiler. Check whether
the two port valve switches to the heating
position after reaching the cylinder
temperature.
Cylinder temperature sensor defective. Check the cylinder temperature sensor
and the corresponding thermal cut outs
and replace the temperature sensor and
reset the thermal cut outs if necessary.
Two port valve defective. Check whether the two port valve is
working and replace it if necessary.
Temperature and pressure relief valve
defective.
Replace the temperature and pressure
relief valve if water only comes out when
heating up with the immersion heater.
Immersion heater defective. Check the temperature sensor of the
immersion heater and the corresponding
thermal cut out and replace the
immersion heater if necessary.
Table 5. Fault Finding (continued)