Sometimes when you register a domain name the fact that the letters are all together can lead some unintentional, and humourous words. For example, domains like The Pen Is Mightier can become The Penis Mightier: thepenismightier.com.
Gas Heating.co.uk was something the owners really should have thought about, as GashEating.co.uk is the way it looks.
More domains like this can be found here.