Antihistamines, H1. Histamine antagonists or antihistamines are drugs that relieve allergy symptoms.Histamine is a chemical used to identify and remove substances that trigger an allergic response. Ã¢ There are four histamine receptors &#40;designated H<sub>1</sub>, H<sub>2</sub>, H<sub>3</sub>, H<sub>4</sub>&#41;.
Quick Answer. Blocked condensation drain lines often cause excessive amounts of water in an air conditioner drain pan. These lines are designed to funnel excess water from condensation away from the air conditioning system inside the home. If these lines become blocked, the excess water drains into a drain pan.
For central air conditioning systems, a clogged condensate drain could cause water to leak from the system. The drain could become clogged with mold. This is one of the easiest and least expensive air conditioning problems to fix. Simply clean out the pipes that channel the water into the drainage system or the outside.