Hello My name is Ian ~ I am not on the site constantly so please be patient whilst waiting for responses to you queries
where is the answer?
Yes there is a small circular piece in the pump that forms a one way valve however this even if it was blown out of the end of the drain pipe wouldn't have caused the flood protection device to activate, this is caused by a leak into the base. You need to find out where the leak is and once fixed the appliance will work as normal once again ~ Ian
Having received an answer to you query would you now kindly rate my service to you using the smiley faces below, once this is done I can shut the job down on the system but you can continue to ask further questions on a free of charge basis. Many thanks ~ Ian