Miele CVA 2650 Technical Information page 100

Technical Information
heater. Remember, there is no bimetal thermostat in a CM5, so one single
temperature overrun will permanently disable the heater.
If you find a heater with an open temperature fuse:
During the diagnosis process, if you find that a temperature fuse has opened,
all of the other parts in this circuit should be suspect.
1. Ohm out the heater element (steam = 12.5Ω and coffee = 12.7Ω; CM5 =
10.6Ω) and be sure to check both ends of the element against the heater
case (ground). This should read infinity (∞). If either of these tests fail, the
heater is bad. The heater may have caused the electronic to fail.
2. Disconnect the heater and see if voltage is present (with the machine
turned off via the electronic, not the mains switch). If voltage is present,
the electronic is bad.
3. Ohm out the NTC sensor (approx 130kΩ at room temp.) and make sure
its resistance decreases as you warm it up. If in doubt, replace it.
4. Once the determination has been made, the parts should be replaced,
and in all cases (except for the CM5), replace the appropriate bimetal
self-resetting thermostat. Refer to the ETD for the appropriate part
numbers. Even though a temperature fuse may be rated at a certain
temperature, its color denotes its response time and/or tolerance. Only
use the specified part.
100
CVA 265x & CVA 266x