A leak is destroying something while the search happens. Unlike a dead socket or a stopped machine, water is coming through a ceiling, which makes these the most urgent queries any merchant receives and the least price-sensitive.
A boiler model with a part name is a purchase. Somebody searching that combination has a broken appliance, a customer waiting and a very short list of places that will have it.
Emergencies come with the water already off. Somebody searching at seven in the morning wants opening hours and a part on a shelf, and everything else on the page is noise at that moment.
Bathroom projects are the other half. A homeowner planning a refit searches for months, spends far more than an emergency and chooses a merchant on advice rather than on urgency.