Ask 'Dr. Spa' Q & A Message Board

: I have a Jacuzzi Quanta with 12kw heater element, looks to have been
: made by Ogden Manufacturing. Part number KV-2-0074-M1, 12000W 240V
: 1phase. My hot tub somehow had a heating element stick on, even with
: the controls turned off. The filter was not running, so doesn't
: appear to be a control issue (reed switches) since if either
: Whirlpool mode or a Heat mode stuck on at the controls, the filter
: should also be running.. unless something funky with Bridge
: "B" or Relay #6 (thermal control relay). At this point,
: thinking relay #1 might have stuck.. the contacts are pretty
: burnished. I'll be replacing that relay & any others with
: burnished contacts.

: Looks like it cooked the high-temp side 6kv heating element (dual
: element = 12kv) as that reads infinite when checking the ohms across
: the high-temp element's wires at the relay. The low-temp element
: reads around 9.8ohms across its wires, but I also tried measuring
: between the low-temp element wires to the ground terminal block &
: it reads something like 70-80ohms..ohms climb up some if I keep the
: meter on it, but in any case seems to me like it should be reading
: infinite.. otherwise looks like it's shorted to ground? The hot tub
: immediately kicked the hot tub heater element breakers & also the
: house breaker for the tub.

: In any case, think I'm in need of a new heating element & these
: things appear to be scarce & very expensive. I tried contacting
: Ogden to see if they offer an equivalent heating element and my email
: to their contact address bounced back. Is there an equivalent from
: them or another manufacturer I can put in, even if it's slightly less
: kilowatt? We'd normally kick the breaker in the house panel if we
: left the tub on high temp setting for too long. Not sure if that was
: due to the high-side element starting to go or just that it would
: keep the elements on longer than when set to the low temp setting
: & got a chance to turn off.. but we'd run on the low temp setting
: most of the time. From what I can tell on the schematics both heating
: elements would be on regardless if in high-temp mode or low-temp
: mode, more a matter of what temperature they're kicked off at (ivia
: settings at temp pots).

The Quanta heater has two elements as you noted, but both elements are energized simultaneously regardless of whether you select high temperature or low temperature. That tub has two temperature settings so that you do not have to get down to the brown control box, open the lid and change the setting. The selector knob on the top control panel is for convenience.

It sounds as if your heater has failed due to either age or water chemistry (or both). The fault to ground is a dead giveaway. Also, bear in mind that power to the elements passes through multiple contactors, so a single sticking contactor is not likely to be a problem by itself. That heater is still available from many industry sources. It's not cheap, but it is very good.

More importantly, this tub pre-dates the requirement for GFCI protection. It sounds like you have never upgraded the electrical protection as recommended years ago by the CPSC. I urge you to replace the 60 amp breaker in your main panel with a 60 amp GFCI breaker while repairing your tub. It could prevent a fire or electrocution in the future. The fact that your fault to ground is now in the 70 to 80 ohm range is incredibly dangerous. A functioning GFCI would have tripped long before reaching this range. Incipient ground faults are generally found with a megohmmeter much earlier than this.

The Quanta is probably the finest hot tub ever made by anyone. The fiberglass is so thick and the electrical is so robust, that it can literally last for decades with a few repairs over it's lifetime. Modern tubs do NOT have those robust contactors anymore and the tub vessels have gotten MUCH thinner. Take care of that fine tub.

John