There are no trains going in and out of Heathrow after flooding and a major signal fault.Passengers are asked to allow extra time and replacement bus services have been laid on.Heathrow Express, which normally runs from Paddington to the airport every 15 minutes, is closed in both directions due to a fault with the signalling system, according to the service's website.The Elizabeth line is suspended between Hayes and Harlington and Heathrow Airport due to a signal failure caused by flooding at Heathrow Terminals 2 & 3, according to Transport for London.