Daikin D2CND028A1AA, Servicing Manual

D2CND0 D2CND0 D2CND0 

D2CND0 D2TND0 D2TND035A4AA

Wall-mounted condensing boiler

ESIE17 - 09 / 2017.11

Servicing manual

37

7.10.10 Sweeper Mode

Sweeper mode enables burner-operation independent to CH 

or DHW modes. Burner can be operated at maximum or min

-

imum capacity at sweeper mode.

Boiler operates at central heating during sweeper mode (The 

diverter valve will switch over to CH position).

Before  activating  the  sweeper  mode,  gas  analyzer  device 

should be mounted to read the flue gas values. 

To activate the sweeper mode follow the instructions below:

Press ‘Menu/Enter’ 

and ‘Cancel/Back’ but

-

tons at the same time 

for 5 seconds (in any 

mode sweeper mode 

can be activated).

‘TST’ caption and 

capacity percentage 

will appear on the 

screen.

When  first  sweeper 

mode  is  activated, 

boiler  will  operate  at 

maximum  capacity. To 

switch between maxi-

mum and minimum ca-

pacities,  press  ‘Mode/

Reset’ button.

To quit the sweeper mode, press ‘Menu/Enter’ and ‘Cancel/ 

Back’ buttons at the same time for 5 seconds.Sweeper mode 

will  be  deactivated  and  boiler  will  turn  to  normal  operation 

mode.

8  SAFETY OPERATION FUNCTIONS

Aim of this function is to fill the condensate trap in case con

-

densate  water  is  evaporated,  due  to  no  operation  for  long 

time. If water inside the trap is evaporated, this may cause 

gas leakage from the condensate trap.

When Low Water temp function is active;

1. CH set value is constant and set to 45°C.

2. Pump runs at 100% capacity.

Function  is  active  for  10  minutes  of  burner  operation. After 

function is ended, boiler operates according to central heating 

setpoint adjusted by the customer and pump modulates ac

-

cording to flow-return temperature difference, as usual.

While function is active,    icon blinks. Please note that Info 

icon blinks independent of burner operation during LWT func

-

tion.

There are two conditions for Low Water Temperature Function 

(LWT) to be active;

1. After power ON; where the boiler has been disconnected 

from mains (230 V) for at least 3 seconds.

2. After each 90 days.

LWT function is only activated if operation mode is “Winter” 

or “CH only” and room thermostat is closed, in other words, a 

central heating demand is present. This is valid for both two 

conditions defined above.

8.1  Low Water Temperature (LWT) Function  

Sweeper Mode and DHW Mode have higher 

priority than LWT function; i.e. LWT function is 

interrupted in case water is being tapped, but 

after tapping is finished, LWT function continues 

its operation.

INFORMATION

The LWT function duration 10 minutes is the time 

that burner is active. If burner stops during LWT 

operation (i.e. 45°C + P18 ‘CH Hysteresis’ is 

exceeded), counter also stops and waits for next 

burner operation. Counter also stops during water 

tapping and sweeper mode.

INFORMATION

8.2  Temperature Gradient Supervision 

The burner will be blocked for at least 60 seconds, if the tem

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perature gradient of the flow-sensor exceeds the limit 5K/s.

Note:

 Temperature gradient supervision is not active while 

sweeper mode is active.

8 Safety operation functions