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.
Emergency Pan Keeps Filling Up We are not sure if this is something we can do ourselves, but I know we are asking in the right place! Two weeks ago our emergency pan under our central A/C unit (it's in the attic) was full of water. It was about 1/2 inch from overflowing. We called the heating and air guy.