When finished with compressor how do I release the pressure

Are you draining water from the air tanks. There should be small taps on the bottom of all air tanks. Locate these and open slowly when system is under pressure. Make sure you close them when finished.

The head pressure is released thru the needle unloader valve at the pressure switch. Notice a 1/4 inch plastic tube (or metal) running from the intank check valve to the pressure switch. After pressure switch reaches set pressure a small tang moves up and presses on the needle valve releasing the pressure. Only a small amount of air will be released. If however air continues to escape from the needle valve, then the check valve is bad.

The pressure switch is faulty needs to be calibrated.

you must have wired the new pressure switch incorrectly .when the pressure switch opens it will release the head pressure so your compressor must be running with the pressure switch contacts open should be 4 connections 2 marked motor which is from your compressor and 2 marked line which is your power coming in

There should be a pressure regulator set to a certain psi make sure it is not set too low or the pop valve will release the remaining air for safety.

When a compressor reaches set pressure, there should be a release of air from discharge hose thru the unloader. This release of air unloads the compressor head pressure. The unloader is usually located within the pressure switch. Easy to check. Follow discharge hose from compressor head to tank. There should be a brass/steel checkvalve at the tank. The checkvalve allows air to enter tank, however not allow air to be released back into discharge hose. If this valve is leaking, air will be released from the unloader constantly. Follow 1/4" tubing from checkvalve to unloader and listen for leaks. Repair as needed. If air is not leaking from checkvalve then check unloader mechanism with-in pressure switch. Parts are available at www.toolpartsdirect.com Good luck

There are two valves in play here. There is a relief valve that opens when the motor kicks off to release the pressure in the compressor itself. That is normal, and is required so that the motor can restart next time without having to overcome that pressure. The other valve is the problem. It is a reed valve between the compressor and the tank. This valve's job is to prevent the air in the tank from returning to the compressor. Think of it as a ratchet for the air. It is this reed valve that has failed.

There is a moisture release valve under the tank that may have been left open. If so, close it and the pressure will build. The reason the tubing heats up is because it is running so long.

Sirwriter

hello,
well,you have to release the pressure,the cut out pressure at 120 psig.reached,and the cut in pressure maybe at 40 psig.so after realeasing pressure at cut in the compressor will run.if the compressor not run at cut in or after releasing check your power supply if still have,swicth off power breaker,by pass pressure switch,by disconnecting the line on terminals of pressure swtich,connect the line w/out pressure switch
the wire line should supply the the compressor,
open the service valve of compressor,switch on
observe if compressor run and develop pressure or air is coming out to nozzle,if that so switch off again and replace pressur switch.you have defective pressure switch,regards rate me,thanks

'When the machine is shut off, disconnect the discharge line out of the head of the compressor. If air releases, replace discharge check valve in tank.