Boyfriend is rough on the a/c

I just shudder when something in my house breaks or malfunctions. My husband Carter thinks he is the master at fixing things. He has a whole bunch of tools and even a whole playlist on his phone for when he tackles a repair. He may look knowledgeable, but he can’t repair anything. Usually, Carter makes the situation worse. My book shelves are not level and they’re loose on the wall. My bathroom sink leaks and none of the doors in the house close properly. The worst is when he goes after my AC system. I am convinced that Carter secretly wants to work for an HVAC company. If he even gets the slightest indication that the AC unit is not operating perfectly, he can’t wait to start working on it. I am not happy  when he takes apart my cooling system. The air conditioner was expensive and it’s a complicated piece of machinery. Most of the time, the Air Conditioner simply requires an air filter upgraded. That is the extent of the problem. However, Carter always wants to take it apart and then violently scrub the inner workings. I am so concerned he is going to bend the fan blades. If he causes damage, I would need to upgrade the whole fan. Whenever he picks up refrigerant, I cross my fingers. Adding too much refrigerant would destroy the cooling capacity. He could easily ruin my AC system, and has probably shortened the lifespan on it. If the AC system shows signs of a malfunction, I have to hide the professional cooling repair from him. I sneak the HVAC technician into  the house like I have an affair going on.