When my electrician fitted my Mira Sport electric shower, he fitted an on/off pullcord by the door. He advised me to leave this in the 'on' position except when going away or if the shower needed attention. But I've now just got around to read the shower's instruction booklet, which says to switch off after each shower. (My spark said that the pullcords soon wear out if they are used on a daily basis.) What are the safety/other implications of leaving the shower almost permanently on?