Breaker Or Heater At Fault?

[bmulhern]

I own a 1996 Hot Springs Grandee. The 30 Amp circuit breaker keeps tripping. The breaker sits next to a 20 amp breaker (for the pumps) in an enclosed access box nearby. This is a 220 volt unit.

Sometimes the 30-amp heater breaker trips immediately and sometimes it occurs after 20 to 40 seconds or so. I measured the amperage with a clamp on meter and see it operates near 20 to 24 Amps.

With the thermostat turned off there is no amperage, so I know there is no other load on that breaker. At the point that the circuit breaker trips, I do not see an increase in amperage on my digital multi-meter. However it might very well increase before the meter has time to respond, due to the display's lag time.

The circulation pump is moving water and I removed the filters in order to ensure good flow. I can see the typical bubbles rising from the drain.

I see that a replacement heater is about $300, so before I commit to that I was wondering if I should replace the breaker first (about $100). I'm looking to see if there is a way to determine if the fault is the heater or the breaker. One technician I read about said in 30 years he's only replaced 2 breakers and hundreds of heaters.

When the heater relay clicks on I do hear a sizzle sound coming from the heater cartridge but wasn't sure if that was always present. More importantly, it could just as well be the sound rushing water would make when passing thru a tube or fitting.

Any suggestions on troubleshooting or guidance is appreciated.

[Spanky]

My bet would be the heater.

You can check tbe element with an ohmmeter. Depending in thr Kw rating it should be about 10 ohms.

Another posibility is cracks or pinholes in the outer sheath. If the heater works for a few seconds that may be enough to open any stress cracks and let water into the inner element causing a short. That may also explain the "hissing" sound before the breaker trips.

[CaptPat]

GFCI breakers don't last forever--in 14 years I've had to replace both the 30a and 20a breakers. Replaced the 30a breaker after a heater replacement did not fix the issue. YMMV

[PreservedSwine]

I'd bet heater as well. It's possible it's the breaker, but much more likely it's a heater that's developed a ground fault. The breaker isn't tripping due to the heater drawing too many amps, a Full Load Amps test won't tell you much. It's tripping because the breaker will also trip as soon as ~5ma of electrical current goes unaccounted for. A very, very common failure (as far as heater failures go).