Van Halen said no Brown M&M’s and I say No Loose King Valves!!!!
When Van Halen would go on tour part of their lengthy checklist was to have all of the brown M&Ms removed. The reason for this is if they didn't pay attention to this detail then surely there were other details that would be missed like properly securing the stage floor for specific weight requirements or other important details. When I do an Air Conditioner Repair in Sacramento CA or the surrounding areas I have my own M&M test and it's to see if the King valve on the A/C is loose. If the King Valve is loose and they often are, I can tell a professional has never serviced the Unit. It's shocking to me because some units I go to have been serviced for years and nobody catches this simple detail.
What is the King Valve and why it's Important that it is not loose?
When a split system A/C is installed the condenser is pre-charged with 4-10A refrigerant. The refrigerant lines get brazed to the Condensing unit and evaporator coil. Then the impurities are removed from the refrigerant lines and the King valve’s are opened to allow the refrigerant to flow out of the condensing unit. The King Valve’s typically have a threaded cap that is brass on brass. What that means is it's not sealed unless its wrench is tight. I've gone to units that lost 100% of their refrigerant from the King Valve being loose. A unit running low on refrigerant can damage the compressor and at a certain age this may be the reason a system gets replaced. Sometimes it's the simple things that can ruin a unit. Besides the king Valves being loose many times I see that the refrigerant caps are missing on the service ports of the Condensing unit. If a unit is 20 years old and is missing refrigerant caps and has loose king valves that's a recipe for a very costly refrigerant refill and years if your A/C running sub optimally.. Not only is it expensive to refill a unit with refrigerant but then there is the question of it being the only leak or is there also a leaking evaporator coil for example.
If your A/C is a split system where the condensing unit is outside on the ground then feel free to check the king valve yourself. Its Hexagon shaped threaded brass cap above the service port just as the refrigerant lines leave the condensing unit. If you can loosen this cap by hand then it's not wrench tight. You might want to call a professional to have the a/c checked to make sure nothing else is missed. But don't bring it up right away. When they’re wrapping up the service make sure the refrigerant caps are in place and then check. If they tighten the caps without you saying anything that's a good indicator the technician you’re using pays attention to details in general.
If you are in need of service or repair please call 916-671-5542
For do it yourself A/C maintenance tips check out this linkhttps://www.sierraaire.com/a-c-maintanance-you-can-do