Ariston AL1250CT UK front loading washer dryer combo not starting

A fairly common problem! The official instructions are

Before using your dryer, wipe the dryer drum with a damp cloth to
remove dust from storing and shipping.
1. Load clothes loosely into the dryer and close the door. Do not
pack the dryer. Allow space for clothes to tumble freely.
2. Turn the Cycle Control knob to the recommended cycle for the type of load being dried. Use the Energy Preferred Automatic Setting (,) to dry most heavyweight and medium weight loads. See "Drying, Cycle, and Temperature Tips."
3. Select a temperature setting on models with a Temp/Fabric selector. The cycle descriptions include temperature setting suggestions.
4. Push the START button.

Stopping and Restarting
You can stop your dryer any time during a cycle.
To stop your dryer
Open the dryer door or turn the Cycle Control knob to OFE
NOTE: The Cycle Control knob should point to an Off area when
the dryer is not in use.
To restart your dryer
1. Close the door.
2. Select a new cycle and temperature (if desired).
3. Press START

Extracted from
http://www.manualslib.com/manual/511763/Whirlpool-Lte5243dq.html?page=10#manual

held on with two large clips

1. Start the drier normally
2. Before the "EHE" error appears, open the drier door!
3. Because the door was opened during program, "dE" error is shown
4. Close the door and press "start/pause" to continue
5. Program will continue normally; problem fixed!

Suggestion: Try a little WD40 spray on the door, not on the machine. Close and open 2 or 3 times while plug is off the wall mains.

Click if helped.

To my knowledge all front loading washers require low sudsing high efficiency (he) detergent and these only come in liquid. A powdered detergent could probably be used, but I'd try a 1/4 of the recommended amount for a normal load first. Also it is not recommended. Regular liquid detergent can also probably be used but i'd start with 1/2 the the amount for a normal load. If you don't use the recommended "he detergents" expect occasional oversudsing problems and possibly even early drain pump death. Hope this helps.
Here is the owner's manual for your machine:

http://www.managemylife.com/mmh/owner_manuals/25710/ARISTON-Laundry-Centers-L0520687

Hello.
Noises are common when using a two-in-one washer and dryer, as clicking or whirring is part of the cleaning process during the transition to the next cleaning process. The GE Spacesaver washer and dryer combo uses a top-loading washer stacked beneath the front-loading dryer, and uses an agitator that makes noises throughout the spin cycle. Although whirring or clicking is normal, other noises or malfunction indicates a problem with the washer that requires minor troubleshooting. Professional repair is necessary if the washer continues to experience problems during the spin cycle, as there may be a problem with the washer's agitator.
1 Open the washer's door and check the balance of the load's clothes. Clothes that are unevenly distributed around the agitator cause excessive shaking and result in an imbalance during the spin cycle. Reduce the load's size by removing clothing if the washer's drum is overloaded.
2 Push "Start/Pause" to pause the spin cycle and turn the washer's cycle knob to the "Off" position. Turn the knob to "Spin Only" and press "Start/Pause" to reset the cycle.
3 Turn the wrench counterclockwise or clockwise around the unit's legs to adjust the appliance's balance. The legs are adjustable with the help of a wrench to ensure the unit does not shake while in use. An unleveled unit shakes as it spins, and causes excessive squealing or rattling as it attempts to dry the clothes.
4 Touch "Start/Pause" on the front of the washer's control panel and unplug the washer/dryer unit's power cord from the electric oultlet. Wait two minutes and plug the power cord back into the electric outlet. Push "Start/Pause" to resume the spin cycle.
Thanks.

This is a door lock error. The control is not seeing that the door was locked.
Try pushing the door closed where the door strike is. If this does not work you may nee to adjust the door strike.

Hey, Just load the washer but do not over load. These combo washer dryers are strictly for smaller loads. You should have a drawer to the left that you place the soap and softer and bleach. Set to the washer to washer. The door should lock automatically. Then set your dryer setting to the the Heat temperature that you want. 100 degrees is ok to start with. then it will adjust itself as it goes through the cycles you have set. Enjoy the machine should work. If it does not look to make sure that the door is closed all the way. Sometimes you have to open the door and reset it and shut the door or while it is closed gently push on it till you hear a small clicking noise. ENJOY YOUR WASHER DRYER COMBO

are you getting three beeps when trying to start, if so door lock problem