Houle's plumbing, heating & air conditioning, (207) 872-6762. Complete the clearance by directing a strong jet of water down the drain from a hosepipe, or by filling the bath and sink and releasing the water in one gush. Free no-obligation safety survey at your home. There are many causes of blockages common causes are tree roots growing into the pipes, a build of soap or grease deposits and disposable nappies. Our triplecare.