When it comes to spa service calls, one of the most common is a ground-fault circuit interrupter (GFCI) that won’t stop tripping.
And more than perhaps any other spa component, a tripped GFCI can
point to a whole host of problems. The GFCI acts like a guard,
detecting any electricity that’s escaping into an improper
part of the circuit, and interrupting the escape attempt.
Whatever the cause of the escaped electrical current, the only way
to find the solution is to work through the circuit, testing each
connection until the problem becomes clear.
Here, we walk through a service call in which a damaged heater coil
was overloading the circuit and tripping the GFCI — and use
this example to demonstrate the general principles of GFCI
detective work on a spa.
1 Turn on the spa and note
when the GFCI trips. If it only takes a few seconds, there’s
likely a break in the circuit, which means that the GFCI is
detecting a ground fault.
2 The most common cause of
a tripping GFCI is a faulty heater, so disconnect all lead wires to
the heater, then try resetting the GFCI. If it doesn’t trip
at this point, the problem was isolated to the heater. If the GFCI
still trips, reattach the lead wires, then begin disconnecting each
individual component one-by-one, and repeat this step.
3 If it’s not
possible to isolate the problem in the above way, the next step is
to remove the cover. Inspect the interior of the GFCI for signs of
corrosion, loose wires or other obvious problems.
4 In this case, the
heating element is compromised, which is allowing electricity to
come into direct contact with the water. The next step is to
disconnect the heater from the GFCI, which removes it from the
circuit. Then remove the old heater coil and install a new one,
making sure no part of the new coil is in direct contact with the
5 Whether the problem
turned out to be a heater or some other component, the wrap-up is
the same: Reconnect all disconnected wires — remembering to
properly ground the GFCI — and open all valves that were
closed. Then reset the breaker and start the spa again. If the spa
runs without tripping the GFCI, the job is complete.