The EH0 error indicates a problem with the incoming voltage or the power supply or wiring inside the dryer. If there has been a problem with the electricity coming into your home (brown out or similar), the error will resolve when the power company fixes the issue. Otherwise the control board is not receiving the expected power from the power supply.
First unplug the dryer or shut off the power at the circuit breaker. Unplugging the dryer for at least 30 seconds will reset the error message. If you can, plug another appliance into the outlet and check if that works. If there is a wiring fault, get an electrician to check the outlet and wiring.
If the problem is inside the dryer, the power supply, the control board and the wiring to the control board will need to be checked. There could be a loose wire, a broken wire or a spot where the insulation has been damaged and two wires are touching. Check all of the wiring harnesses where groups of wires plug into the control board. Replace or fix any damaged parts or wires. The parts diagrams are available here: https://www.ransomspares.co.uk/parts/brands/electrolux/tumble-dryers/edc2086glw%20(91609724100)/
. If the dryer is under warranty, contact Electrolux to have the unit serviced.
I hope this helps.