Plum ecoMAX 200 W, Operation And Maintenance Manual

Page: 26 / 27

26
16 Description of possible faults
Signs of a fault Hints
1. The display is blank
despite connection to
the supply network.
Check:

if the main fuse is burnt-out, replace if so,
2. Preset boiler
temperature on the
display is different than
the programmed one
Check:

whether the hot utility water tank is filled at the time and the
preset hot utility water temperature is higher than the boiler
preset temperature; if so, the difference of readouts will
disappear after the hot utility water is filled, or after decreasing
the preset hot utility water temperature.

whether the room thermostat is on – set the service parameter
Decreasing boiler preset temperature by thermostat r0 = 0
3. central heating pump is
inoperative
Check:

whether the boiler exceeded the parameter Pump activation
temperature (n0) – wait or decrease this parameter,

if the room thermostat is not blocking the central heating pump -
set the parameter
central heating pump down-time (n8) to “0” .

if the hot utility water priority, which blocks the central heating
pump, is enabled – disable the priority by setting the
hot utility
water mode = 2 ( Without priority),

whether the central heating pump is not damaged or clogged.
4. the fan is inoperative

check the value of the parameter Minimum airflow power (n2)

check if the safety temperature limiter STB input jumper is on
terminals 1-2 (the jumper should be placed only if no
temperature limiter is connected).
 check if the additional thermal protection sensor input jumper is
on terminals 11-12 (the jumper should be placed only if no DZT-
01 sensor is connected)

if the boiler manufacturer equipped it with a temperature limiter
STB with manual return to the initial position, unlock it by
removing the lid and pushing the button, in accordance with the
documentation provided by the boiler manufacturer.

check the fan and replace it if necessary
5. the temperature is
measured incorrectly

Check if there is good thermal contact between the temperature
sensor and the measured surface,

whether the sensor lead is not placed too close to the mains
cable,

If the sensor is connected to the terminal,

Whether the sensor is not damaged – check it in accordance with
point 11.8
6. in the hot utility water –
SUMMER mode, the
heaters are hot and the
boiler overheats

Increase the parameter Extending hot utility water pump
operation (r4) in order to cool down the boiler
7. the hot utility water
pump is active even
after the hot utility
water tank has been
filled

Set the parameter Extending hot utility water pump operation
(r4= 0)
8. the boiler overheats
despite enabled fan

The reason can be a constructional defect of the boiler,
consisting in lack of protection against too high chimney draught
(no back shutter in the fan, or damaged shutter), or the boiler is
not tight.