Colman Spa trips GFI what is most common problem? GFI test good. Pump disconnected still trips, is heater most likely? Can you replace only heater? thanks

GFI tripping is caused by an excess of electrical current between the device and the ground connection. The heater and pump should be on separate GFI circuits. Check to see which device is causing the fault and have it repaired or replaced.

Easy way to test for the heater issue is to disconnect the heater from the board. Disconnect both leads from board and let the spa call for heat. There is also a chance the GFI breaker is bad however most times the heater fails and the breaker is doing its job.

Most common reason a gfi trips is the heater or blower have failed!
Unplug each one, one at a time...
whatever is unplugged/disconnected from board and the gfi stays on, that piece is the bad item and needs repair/replacement.

Something in the electrical system supplied by the GFI breaker has a ground fault. The current to ground required to trip a GFI is very little such that dampness on any electrical connection can trip it. This is especially true with motors that have a lot of fine wires in the windings and are open to allow cooling.
Hard water and pool chemicals all are worse than condensation from the air because of their ionic nature.
If the same GFI powers the pump it is what I would suspect first. Your question got cut off before the result of the fan disconnect which if disconnected didn't trip the GFI, is probably the problem. But you should open whatever you can access containing electrical components and make sure everything is dry

make sure the spas control panel is set for 230v next check the GFIC it might be faulty. AS A TEST ONLY you can bypass the gfi af all works, try another GFI. but this doesn't rule out.. shorted motor,heater or even a light ..
give me a vote if'n I was of help.I love praise, it's the fuel that keeps me fix'n yer stuff.. Jay

commonly its the heat element that trips the breaker. find the heater connection and remove both sides. make sure to tape ends and then try the breaker...if it holds replace the element

#1. DO NOT GET INTO TUB FULL OF WATER WITH A GROUND FAULT.
2. There is a short. You need to get multimeter and start checking each part for current running to ground wire.
3) Power is ON. Connect power without GFCI.
4) Tape tester leads to wood sticks to keep hands away from power.
5) Do not touch anything directly or you will become the ground rod.
6) Ground wire must be present, and bonded back to main panel box.
7) Do not sit or touch directly on cement or bare ground. Do not touch or lean into anything made of metal.
8) Body and parts must be on sheet of plywood, or similar non-conductive dry surface.
9) Test each part with spa, but also test electric line coming from main box.
10) GFCI will also trip with any fault detected on line. So the wire coming to spa may have the fault.
11) Add a new dedicated line from main box to spa.

http://waterheatertimer.org/How-to-wire-GFCI.html
http://waterheatertimer.org/See-inside-main-breaker-box.html

If you need further help, I’m available over the phone at https://www.6ya.com/expert/gene_9f0ef4df2f9897e7

It sounds like there may be a short in it causing the breaker to trip. I would disconnect the wires from the new element, tape them up and test for the problem again. If it still trips it is not related to the heater element. If it still trips it is not related to the heater element and therefore additional diagnostics need to be used to find out what is is wrong.

Gfi's will trip when there is a very small variance in the power across the circuit.
Check all the grounding connections, and all the terminal connections to make sure they are tight and secure.
Also it would be wise to check the GFI with a separate tester. They can malfunction, you can get a testing plug at a local hardware. It has a plug with lights on it and a test push button. Very handy to have in your tool arsenal as well.
If it checks out, then it's very likely it's doing its job correctly and protecting you from a worse issue.
If you cannot check these wirings, have a pro help you out.... better to spend a little than get shocked while in the tub...
k