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.
If the filter appears dirty, replace it immediately. A dirty filter will cause ice to form on the unit's evaporator coils, and when that ice melts, it drips water. The third reasonâa stopped-up condensate lineâis the most common cause of A/C leaks. The condensate line drains condensation from the overflow pan to the outside or directly into a drainpipe. When the line is clogged, water backs up and floods the overflow pan.