The Germans - S1-E6
Trivia: Although this episode is entitled "The Germans", the first German guest we see doesn't appear until 23 minutes into the episode.
The Germans - S1-E6
Trivia: This is the only Fawlty Towers episode that doesn't have a hotel sign at the beginning. The episode opens at a hospital.
The Germans - S1-E6
Trivia: The hospital used during the opening titles is Northwick Park Hospital in Middlesex.
The Builders - S1-E2
Trivia: You will probably recognise the actor who plays Lurphy in this episode - it's Michael Cronin, best remembered as the PE teacher Geoff "Bullet" Baxter in the children's show "Grange Hill".
The Germans - S1-E6
Trivia: In this episode, the jacket Andrew Sachs wears was treated with acid by the special effects department to look as if it was really on fire. Unfortunately it really did burn through to his skin and he bore the scars until he died in 2016. Sachs was paid damages by the BBC.
Answer: It's "Leisure Complex" by Dave Gold and Gordon Rees. Can be found on YouTube. The relevant clip is around 25 seconds in.