Worcester ZWBR 7-30 R 30 HE PLUS COMBI Service Booklet page 19

A7
flashing.
Water NTC sensor defective
Check
B Activate menu option Show serv-
1.
ice parameters.
B Select service function 0.2 Hot
water temp. sensor.
Is a temperature between 0 and
5˚C displayed?
B Unplug 20-pin connector from
2.
PCB.
E2 is displayed.
B Check resistance from connec-
tions 3 to 4 on the cable side.
Does the value match the ones
described in table 7, page 50?
B Unplug NTC sensor from cable.
3.
B Check resistance of NTC sensor.
Does the value match the ones
described in table 7, page 50?
1) For notes, refer to Appendix
7 181 465 347 (05.01)
Supplied By www.heating spares.co Tel. 0161 620 6677
Action
yes:
DHW temperature limiter connector corroded
damaged or dirty?
B Change relative parts.
A7?↓2.
↓2.
no:
B Make a note of the altered service function set-
yes:
tings (see table 1 on page 7) in order to keep the
altered values.
B Power OFF the appliance.
B Disconnect the boiler electrical connection.
B Change PCB control board.
B Reconnect the boiler electrical connection.
B Turn ON the appliance.
B Restore service settings previously noted down.
↓3.
no:
B Power OFF the appliance.
yes:
B Disconnect the boiler electrical connection.
B Change the 20-pin connector lead assembly.
B Reconnect the boiler electrical connection.
B Turn ON the appliance.
B Change NTC sensor.
no:
Rectifying faults
Error A7
1)
,
19