Emergency
Ring and you will speak to Brad directly. He will tell you straight whether it needs someone tonight or whether it can safely wait until morning, which sometimes saves you a callout.

What's included
Turn off the stop tap if water is coming in. It is usually under the kitchen sink or where the mains enters the house, clockwise until it stops. Keep away from anything electrical that is wet, and switch off at the consumer unit if you can reach it safely. If you can smell gas, leave the house, do not touch light switches, and ring the National Gas Emergency Service on 0800 111 999 first.
Questions
You will get Brad rather than a call centre. If he is under a floor and cannot pick up, leave a message and he will ring back.
Often not, and you will be told so. A leak you have isolated at the stop tap can usually wait until morning, which saves you a callout charge.
Usually under the kitchen sink, in a downstairs cupboard, or where the mains pipe enters the house. There is also an external one under a small metal cover near the boundary, which needs a key.
Once, yes. If it locks out again straight away, stop. Repeated resets will not fix it and can make the fault worse. Note the code on the display; having it ready often means arriving with the right part.
Leave the property, open doors on the way out, do not touch light switches or anything electrical, and ring the National Gas Emergency Service on 0800 111 999. Ring us afterwards.
Ring and you will speak to Brad directly. If it can safely wait until morning, he will tell you that too.