GFCI Trips When Powering up the System

GFCI Trips When Powering up the System

 

If this is a new installation and your GFCI is tripping, make sure that the GFCI was installed correctly, Licensed electricians have been known to install GFCI breakers incorrectly. Please refer to this link to confirm that it was done properly GFCI Load Center Wiring Examples
  • Step 1
    Unplug heater from control box or remove wires going to the heating element:
Because most GFCI trips are heater related, we will start our test by looking at the heating element. Some heaters unplug from their main source, the control box. If yours is capable of doing this, then unplug it otherwise remove the wires going to the heating element and then reset the GFCI. If the GFCI does not trip, and all other components begin to work, then you have solved the problem. Replace the "heating element". If the GFCI still trips after doing this, then go to step 4, water has flooded air blower. If you did not find a way to unplug the heater from its main source, then, continue on to Step 2.
  • Step 2
    Checking for a short in the heating element:

In this step you are going to check for a possible short in the heating element using your multi-meter. Place the selector dial of your multi-meter on the Ohm selection. Some multi-meters have four or five placements to set the dial, start with the first one for now - RX-10k or RX-1k. NOTE: Many amp-meters come with the ability to test for Ohms, but they do not have the sensitivity level that multi-meters have, and are not recommended for this test. Before doing anything else, TURN OFF THE POWER TO THE SPA!

 

Common Heating Elements

Shown above are the most common heating elements and their related housings used in the spa industry today. Using these as guides, let’s continue. Disconnect the wires at the heating element post, before doing the following test. Using your multi-meter with the selection of Ohm, take one of the test leads and place it on one of the element post, #1 or #2, it does not matter which one. (See FIGURE above) Take the other test lead and place it on "A", this is going to be either the mounting nut or the mounting plate. You are now connected to take a test. Look at the needle on the meter. It should not have moved from its resting point AT ALL. This is where you might move the selector dial on the multi-meter to different Ohm selection readings. Again, it doesn't matter which selection you have chosen, the needle should not have moved at all. If you are using a digital meter, make sure that it sensitive enough to take this reading. Regardless which type meter you are using, you should not be getting a reading, if you do; the element is shorted and needs replacing.

  • Step 3
    Heating elements that have dry fired:

Many times, as you go to replace the heating element, it will look perfectly fine, but, as you found by the test, it is not. Other times, it will look charred or burnt, this is called a "dry fire" and can be caused by a few different things. Mainly, they are caused from slow water flow or a lack of flow, through the system,There are 5 things to check: 1) The filter, if it is old, clogged, or dirty, will restrict the water flow. (Replace it). 2) The shut-off valves? Did you reopen them after you cleaned the filter or drained the spa water? 3) Are all the jets open? Closing one or two for more pressure on other jets is ok, but, if they all get closed; this could cause a flow issue. 4) Check the heater contactor (see figure below) inside the control box to make sure that it has not arced shut by chattering (the spring-loaded bridges moving up and down at a rapid speed). If the picture above does not help in locating the heater contactor, then follow the wires from the heating element (attached to the posts) back to the heater contactor. Inspect the contacts making sure that they are not arced shut, and can move freely up and down. If they have arced shut, this will cause continuous power being supplied to the heating element resulting in a "dry fire." In most cases, a contactor will arc itself shut due to "chattering" (the spring-loaded bridges moving up and down at a rapid speed). This can be caused by: A. Low water level in spa.
B. Old, dirty or clogged filter (Replace it.).
C. Pressure switch needs to be adjusted or replaced (Not all spas have pressure switches). See picture below:

 


5) Sometimes after draining and refilling your spa, you may find that when you demand the jet mode, you hear the motor but nothing is coming out of the jets. This is commonly called an "air lock." Air has become trapped in the pump, not allowing the water to enter in. If your spa is not equipped with a pressure switch, then the "air lock" would cause the heating element to "dry fire." To remedy this problem, you must make a way for the air to escape. Open a valve close to the pump or break loose a union that is attached to the pump until you hear all the air escape and a flow of water replaces the air. TIP: It's a good practice to turn the thermostat down to the off position making sure that a good flow of water is streaming from the jets before turning it to the desired mark. NOTE: Newer spas are equipped with pressure switches not allowing the heater to come on without a certain amount of water flow. It is some of the older spas, (pre-1990) that are being referred to.
  • Step 4
    Water has flooded the air blower and or ozonator:
Water backing into the air blower or ozonator is another cause of GFCI trips. This happens for one of two reasons, either the check valve that is plumbed in the same line as the air blower has failed, or, the water level is often kept at a much higher level then recommended. This will cause seepage through the check valve allowing water to drain into the air blower or ozonator. In both cases, the check valve should be replaced. The blower motor will probably have to be replaced. See Blower Motors. Ozonator's also have an in-line check valve in the clear tubing attached from the ozonator itself to the specified jet that the ozone is injected. If the check valve fails or if the tubing is not attached higher than the water level, water will back up into the ozonator causing the GFCI to trip. See Ozonator's.TIP: Unplug the blower and ozonator one at a time from the control box. If the GFCI does not trip after doing this, and everything else is in operating order, then you have solved the problem. Replace the check valve and blower motor or the ozonator Find both these items in the Spa Parts Index. A FINAL NOTE: Although, it is a rare occurrence, motors with shorted out windings have been a cause of GFCI trips as well as transformers in spas with printed circuit boards another rare cause of GFCI trips are pressure switches Back to Troubleshooting Your Spa