Some units have a small looking glass in the line. you will be able to see the fluid running through it. if there are bubbles moving with the liquid most likely your fluid is low and there is a leak.
no. How could you have a leak without a leak? There's a hole in the system somewhere.
Usually there is a leak somewhere in the system.
Pressure testr the cooling system and obseerve where leak originates
Either you can have a leak from the internal venting system that is causing this or you have a leaking heater core instead.............
Your central air conditioner may make a loud noise when it comes on. This is because it may have a leak somewhere in the system.
You may need a check valve in the vacuum supply line feeding the HVAC system or you have a vacuum leak in the HVAC system.
The answer should seem obvious... you have a leak. It could be anywhere in the system, which is unfortunate for you. You'll probably need a tech to come and do a leak test on your system.
check fluid level first if too low you will have air in the system and no heat check for leak or faulty radiator cap
A reputable HVAC service Co. will locate and repair the leak and recharge your system.
You probably have a leak in the heater core.
No. But in the case of a severe leak you may smell oil for a time. After that though you will notice nothing since the average home central unit only holds about 5 lbs of gas, so a large leak will not last long.
Yes a heat pump reverses the function of an air conditioner. Like any refrigerant system if a Technician says "it needs Freon", make sure the leak is repaired first.