240v switch turned on with no water in the boiler. Now blowing cold air with steam coming out of the outside vent/cowl

James Ryan, February 2017

You appear to have a Trumatic C6002 combination boiler (made by truma) probably fitted in a caravan.

It should blow out warm air but only blows cold.

You might do best to call in a specialist engineer

https://www.truma.com/uk/en/home/dealer-search.php

Good Luck..., February 2017