No trains will run on the Heathrow Connect service on Wednesday (November 1), its operator has said.
Work to repair a track circuit failure, which occurred on Tuesday (October 31), has resulted in overnight repairs which are expected to run into much of Wednesday.
Users are being told to use alternative routes, which include the Heathrow Express or the GWR Services to Hayes and Harlington followed by the 140 bus to Heathrow Airport .
Piccadilly line services also run between Heathrow and central London.
Heathrow Connect tickets being accepted on local buses, GWR, Heathrow Express and the London Underground.
The service links the airport to Paddington station, with trains departing every 30 minutes and stopping at key stations, which include Southall, Hanwell and Ealing Broadway.
The track fault occurred at Ladbroke Grove .
A similar problem affected services in October.
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