DE means the Dead End detection on the controller has shut off the pump. This happens when the controller detects the water flow has been stopped. In normal operation this is most likely due to turning off a pole tap or kinking the hose line as you move between windows.
The controller is designed to detect when water flow has been stopped, so that the controller will stop the pump well before a pressure switch would. The advantage here is that the system is under less pressure reducing the risk of blown connectors or split hose lines.
Also the control is designed to know when the flow has been restored. It does this by carrying out a dead end re-test every 3 seconds. If the flow has been restored, (pole valve opened or kink removed) the controller will turn the pump back on. We have engineered the V11 in a way that even if left in DE for prolonged periods pressure will not build up in your system.
The longest delay between opening a tap and pump restart is three seconds.

DE is also used as an error message so in the event of the control unexpectedly displaying this message please check the following information:
1. Run the pump to bleed any trapped air from the system. Turn the controller up to 99 to increase flow ad force the air out. 
2. Check that the hose has not become disconnected, twisted or blocked.
3. Check that the water tank is not empty.
4. Set the calibration to a slightly higher value.
5. A blockage in the jets, the hose line or pipe work after the pump. To check for a blockage start by removing the brush, does this clear the DE? If not then next disconnect the pole hose and so on you may end up right back at the pump outlet.
6. Stuck non-return valve on a trolley infeed.
There are a number of factors that will affect DE and the length of time it takes the control to DE and stop the pump:
1. Ambient air temperature. The temperature will effect the hose wall stiffness and expansion qualities of the hose. The change to hose wall expansion will effect how long the system takes to pressure up
2. The thickness and stiffness of the hose wall.
3. The size of the hose or microbore.
4. Low Battery voltage.
In our tests we have found that a drop in voltage will slightly increase the dead end detection time but this change is minuscule. Certainly, this tiny increase will not cause any extra wear on the pump, battery or fittings. In addition, remember that as the voltage drops the pump will run slower, dropping flowrates and pressures.
In most cases the controller is reporting a system fault. If having carried out the above checks, the controller is still showing DE then run the auto calibration as calibration may be too low.

Analogue controller uses LEDs to display the following information:
RED LED = PS the pump pressure switch has activated 
BLUE LED = DE the control has detected a dead end 
GREEN LED if Solid battery voltage is 11V or lower. If flashing battery voltage is 10.5V or lower. The pump will be shut down to protect the battery. (Note. The analogue has smart battery management but can not display current voltage).
The Analogue controller has many of the features and self-protection measures also seen in the digital controller. Using only LEDs it is more restricted in what information can be displayed to the user.

Ensure that the brush, pole and hoses are connected, any pole valves are open and water is able to flow.
1. Turn the controller on either by pressing the up or down button. Hold the button until the display lights up.
2. Press the up button until the display shows 30 (water flow rate).
3. Press and hold the up and enter buttons together to select calibration.
4. Use the up and down keys to select your chosen value e.g. C50
5. Press the enter button to keep the setting (Set) and exit calibration.
You can also set up the calibration automatically.
Ensure that the brush, pole and hoses are connected, any pole valves are open and water is able to flow.
1. Turn the controller on by pressing either the up or down button. Hold the button until the display lights up.
2. Press the up button until the display shows 30 (water flow rate).
3. Press and hold the up and enter buttons together to select calibration.
4. Press the down button to until you read '0' then press down again to get 'Aut' auto calibration 
5. Press enter to start auto calibration.
NOTE! The display will flash 99, but leave the controller for a few minutes as it is sensing the system default setting.
Then:
1. The calibration value will be displayed. e.g. C45
2. Press the enter button to keep the setting (Set) and exit auto calibration.
3. The controller will remember this setting. 
4. Your system is now ready to use.

NOTE! After auto calibration has calculated a value you can still adjust this manually (by pressing up or down) before pressing enter to set the value. Each system will differ slightly so there is no standard auto calibration value. As a general rule you should see a value between 30 and 60, and when working your controller should typically use a flow rate set between 20 and 50.