Blue Ridge Spa (division of Gatsby / Jacuzzi) flipping breaker when heater comes on

[csdude55]

I've been working on this for about 2 months, so I'm hoping for a second opinion before I throw a ton of money at it.

 

History

This hot tub was here when I bought the house in 2004, so it's roughly 20 years old. It says "Blue Ridge Spa", which I've since learned is a division of Gatsby, which I think is a division of Jacuzzi.

Over the years I've done all of the repairs myself, and have replaced pretty much everything except for hoses at one point or another.

 

The problem

In February 2022, I came home from a trip to find the hot tub completely drained and the power was off! It had gotten down to 18F while I was gone, so I assumed that something had frozen and burst. I didn't mess with it until July, when I traced it down to the pressure switch in the heater being blown out (literally, blown apart).

I bought a used replacement heater and replaced the old heater and pressure switch, then filled the tub and turned on the breaker. Everything seemed fine, but after about 10 minutes the breaker flipped.

I tried again while watching from underneath, and when the breaker flipped again I saw literal sparks behind the Heater 1 / 2 connection in the main circuit board.

I unplugged the heater and flipped the breaker back on for testing. The incoming voltage is definitely 240V.

I measured the voltage at the heater, and both legs have 123V. That's measuring with the positive lead on the hot wire and the negative lead on the green / ground wire. I haven't measured while the breaker flips, though.

From there I replaced the heater yet again, just to rule out a bad second heater since it was used. After a few minutes, the third heater (with new pressure switch) flipped the breaker, too.

That should eliminate the heater, pressure switch, and cords as the problem.

Can you think of any other possible problem here OTHER than the circuit board?

[RDspaguy]

7 hours ago, csdude55 said:

measured the voltage at the heater, and both legs have 123V. That's measuring with the positive lead on the hot wire and the negative lead on the green / ground wire.

Test from one lead to the other.

7 hours ago, csdude55 said:

Can you think of any other possible problem here OTHER than the circuit board?

Several.

Lets start with some pics of the circuit board, wiring diagram, and equipment area so we know what we're dealing with here.

[csdude55]

Thanks for the reply! It's raining today, so I'll update tomorrow. The hot tub is built in to my deck with the motors and circuitry under the deck, so I have to crawl under there to get pics.

[csdude55]

This picture is just the top of the hot tub itself, so you can kind of see what I have on the deck. The power is off in that photo, and that's a garden house filling it up inside of the filter chamber.

 

This is the topside control. That's not original, several years ago I had to replace the main board and replaced the topside control, too.

 

Here is the rebuilt heater that I purchased locally. You'll see that the seals didn't quite line up so it was leaking from the top, but I fixed it after taking the photo. The hose in the bottom right of that photo leads to the circulation pump that's maybe 8" away from the heater.

 

This is the main board. The black port you see in the bottom right goes to the heater. I've checked all of the fuses and they seem fine. The only thing that doesn't look perfect (to me) is a capacitor in the middle-right (SouthWest of the black line to Heater Line-1) that has a little electrolytic gel on the board, but that looks pretty old so I don't think it's the source of the problem.

 

This is the wiring diagram that's on the inside cover to the main board.

 

Today I used an air compressor at 15lbs to blow out behind the board, hoping that there might be something behind it that's causing a short. Then I turned on the breaker.

Measuring voltage from the black wire to the white wire (at "Heater Line 1 / 2 in the upper right of the board) didn't read any voltage when I first turned it on, but measuring with the black lead to ground gave me 123V on both.

After several minutes, I heard a "BRRRRT" sound that lasted for about 2 seconds, then a flash behind the board near the upper right before the breaker flipped off. Then there was the not-unpleasant smell of pennies and ozone. I'm making an educated guess that this is when the board tried to turn on the heater, but shorted.

[RDspaguy]

12 hours ago, csdude55 said:

Measuring voltage from the black wire to the white wire (at "Heater Line 1 / 2 in the upper right of the board) didn't read any voltage when I first turned it on, but measuring with the black lead to ground gave me 123V on both.

This means the heater is off. One leg (120v to ground) is always on, the other is switched. So testing to ground you will always get 120v. 

 

12 hours ago, csdude55 said:

I'm making an educated guess that this is when the board tried to turn on the heater, but shorted.

Not shorted. Sounds like a bad relay. Remove the board and check the back for burns.

[csdude55]

3 minutes ago, RDspaguy said:

Not shorted. Sounds like a bad relay. Remove the board and check the back for burns.

Hahaha, easier said than done! But I can't think of any variables beyond the board, either, so I guess it's coming out either way.

I just replaced the board in 2018 for $500, and God only knows how much it'll cost this time 😕

[cranbiz]

I typed this prior to RDSpaGuy and somehow didn't hit send.

Sounds like a bad relay. Relays can be replaced by someone with soldering experience. No need to replace the board if it's just a relay. If you are not comfortable doing this, a shop that does electronic repairs can do it for way less than replacing the board. The relays run 8-10 each on Amazon, refresh all of them for under $100 in parts and the shop might charge $125.

If you do end up going the board route, I would just buy a replacement Balboa pack with topside. It will upgrade you to a more modern pack and could be less than replacing that board like for like.

[csdude55]

I haven't soldered anything in years (decades, honestly), but as long as my iron hasn't rusted or something then I should be able to swing it. Might actually be fun 🙂

I'm already $200 deep (for the used heater), and it's REAL hard to come up with another $500+ for something that I use like 5 times a year. But I can swing $100, I think. Well, that plus the cost of new solder, I guess.

It's raining now, so I'll try to pull it out on Tuesday and see what I see. Labeling everything so that I can put it back together is probably going to be the most tedious part, I think. Either way, I'll post back with updates.

Thanks for all the help!