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;.
Water leaks in central air conditioners are almost always caused by a problem with the condensate pan or drain pipes. The most common of those problems is a clogged drain line. When your condensate drain line gets clogged, water backs up and builds up in your pan. With nowhere to go, that water will begin to leak over your drain pan and onto your system and your floor. Another problem that can lead to a water leak is a crack somewhere in the pan or in the drain pipes.
How to Fix a Frozen Air Conditioner. To fix a frozen air conditioner, first you have to figure out what caused it to freeze up in the first place. No matter what, the first thing you should do if your air conditioner is frozen is turn it off and let it defrost â this will prevent any serious damage to the system. Next, check all the air filters in your home to see if they are dirty or blocked. If they are dirty, clean or replace them.