Jump to content

Hot tub reaching 120+ temp


Recommended Posts

SO thought I was out of the woods with my hot tub problems after cracking the previous chip issue, but here we go again. 

I found the hot tub was off and checked the breaker, nothing, checked the panel and found one wire had been fried. There was green coorsion and it appeared to have been on fire for a minute, thank god nothing worse. 

For some reason the wire from the heater to control board had been cut and reconnected. 

I replaced the entire wire, 10 gauge with for connectors and it turned back on. 

But when I went out after leaving it on over night it had gone up to 120+ degrees. 

I found and replaced another wire which was for the flow switch and then turned it down to 65 degrees. 

The heater light doesn't indicate it is heating but the temp rose from 74 to 78, but the actual temp using an IR thermometer shows 95 so I know something is off. 

Assuming it could be the whole circuit board or the high temp sensors, but no idea where to start.

It has no circulation pump but continues to circulate like the heater is running. 

Any thoughts?

Date 02/11/10 Model J270 (jacuzzi)

Serial # OZT3LED - 100366630 - 0210

 

 

Link to post
Share on other sites

Post a pic of the circuit board and heater.

What errors were on the display? 

2 hours ago, rseeley said:

one wire had been frie

Which one?

2 hours ago, rseeley said:

had gone up to 120+ degrees. 

Actual temp, displayed temp, or both?

2 hours ago, rseeley said:

temp using an IR thermometer shows 95

In the tub or on the heater?

  • Like 1
Link to post
Share on other sites

Originally the error that was on display was " - - -" which I've read is the watchdog message. 

The wire going from the heater to J34 on the circuit board. 

Actual temp was 120+, display temp was 99 or so. 

In the tub the thermometer ( I used two) is 90 degrees now but the hot tub shows 70 degrees. So clearly something going on there.

We always kept it set around 75-80 which if this is correct was around 90 or so since I never thought to compare the water temp displayed with another thermometer.

 

1816263499_File_001(3).jpeg

1310835121_File_002(3).jpeg

944359310_File_003(3).jpeg

File_000 (3).jpeg

Link to post
Share on other sites

Test the high limit disc. Also remove the red heater wire and get rid of the yellow marrette and run the black wire from the board directly to the heater. When removing the 3/8" nut on the heater be sure to hold the 1/4" nut behind/under the 3/8"nut and heater wire eyelet. Hold it firm and make sure it doesn't twist/turn. Let us know results. 

 

Link to post
Share on other sites

Red wire removed, placed directly to the heater.

Image shows what I believe is connectivity at the high limit disc but not entirely sure so picture included. 

Upon start up

LED comes on, flashes 560 or something similar then no jets but the heater then kicks on

Heater continues until it displays oH.

Presumably because its heating up in place and not flowing through the water.

Jets kick on once oH is displayed. 

Temp set at 65, display says 69 but thermometer reads 90 degrees.

So could it have have again forgotten that it doesn't have a circulation pump as was fixed in my previous post with a chip replacement? Just wanted to provide context to the mystery. 

 

Any thoughts?

(Thanks ahead of time, love this forum)

6B43C3A2-67B7-4A1C-93D8-E4F8046A7231.jpeg

Link to post
Share on other sites

Sounds like you have a stuck heater relay. A loose connection at the board could have caused this, as could simple age and use. The high limit relays will not turn it off until the heater itself reaches a high temp, usually between 110-120, not sure on this system.

The pump running in response to the overheat is normal. But it should not run the heater with no flow, so test the pressure switch.

The sensors may be bad or just reading the temp where they are. Check that they are properly installed.

I would say disconnect the heater and test it out. Make sure it is turning on the low speed pump when it calls for heat and that the pressure switch is working properly (open when pump off, closed when on). Check the sensors and note any errors on the display. Post results.

Link to post
Share on other sites

Attempted to adjust the flow switch and after powering it back on I saw the following 

560 on display

same Time heater turns on

adjusting flow switch a bit more then I get a FL2 on the panel 

heater over heats and prompts an OH again. 
 

When I move the temp above 71 I do see the heater light turn on and had a click. 

also of note I checked the heater with the thermometer and it was 71 like the read out. 

Link to post
Share on other sites
58 minutes ago, RDspaguy said:

would say disconnect the heater and test it out. Make sure it is turning on the low speed pump when it calls for heat and that the pressure switch is working properly (open when pump off, closed when on). Check the sensors and note any errors on the display. Post results.

 

Link to post
Share on other sites

Disconnected heater and turned it on. 
start up followed by firm where but no jets turned on. 
I increased the temp and still nothing. 
the heater light didn’t turn on. 
just to verify I reconnected the heater and on power on the sound of the heater turn on right away but didn’t turn the light red. 

Link to post
Share on other sites

So you have multiple issues. Your heater relay is stuck on and your low speed pump is not turning on as it should. 

Does the low speed pump turn on with the button? If not, test voltage to the low speed pump. If so then there is some logic error, such as faulty sensors or dipswitch settings, preventing it from coming on.

Link to post
Share on other sites

I did previously have the wrong logic chip. I ordered a new one and it worked up until this point. See previous thread link a few posts back. 
 

Since that’s the lowest cost should I try replacing that first?

Link to post
Share on other sites

Test sensors by testing resistance on each one. If the system thinks that the spa high limit is overheating it will run the high speed jet and you can't turn it off. Given that it is running the heater when it should not be, that may be correct. The sensor may have been damaged as well.

Link to post
Share on other sites

The temp sensor is attached to the board just above where the pressure switch connects. 

Hi Limit is the round disc you tested earlier...I would disconnect the wires from it before testing.

The heater relay and pump relays are the black squares attached to the circuit board. At some point I would pull the board and look for dark or burnt areas around those black squares. 

The way the board has been cobbled together I don't have confidence you will find the issue...but keep going something might pop up.

I would also replace with new/redo... the pressure sensor wire where it has been cut and pieced together. 

Sensor Testing tips here: https://www.globosurfer.com/hot-tub-temperature-sensor-testing/

Jacuzzi Resistance Chart Here:   https://www.fortywinksonline.com/localimages/jacuzziresistancechart.pdf

Link to post
Share on other sites
3 hours ago, CanadianSpaTech said:

Hi Limit is the round disc you tested earlier.

No, that is a self resetting manual high limit, called a "thermo disc". This unit also has a digital high limit sensor which should share the plug with the temp sensor. Test each and post resistance readings.

The heater relays are the black boxes above the heater terminals on the board.

Link to post
Share on other sites

Didn’t see any black heat damage on the back of the board. I think that smoke on the case is from a previous issue.  But correct this board was cobbled together. Should that be my next move? Try swapping out the boards? If the high limit and temp sensor both read normal?

90E91797-717E-499F-9338-EA0AA6FE9917.jpeg

E9D3C080-48A8-4B2E-96CF-3A2008A4F912.jpeg

Link to post
Share on other sites

I also attempted to test the high limit and temp sensor but couldn't get a resistance reading on them. Even after taking the wires out of the casing it still continues to read 1. 

Do I have the correct tool for this job? Multimeter option was 2K Ohms per the picture. 

Considering the temp is consistently 20 degrees lower than thermal temp, I assume that at minimum needs to be replace.

And then the fact that the heater keeps going without the pump one being on would indicate an issue with the circuit board or the child I inserted?

File_000 (10).jpeg

Link to post
Share on other sites

The chip tells it if it has a circ pump or uses low speed on the main pump. In any case, the heater should not turn on without the pressure switch reading flow. So either the pressure switch is faulty and the chip is wrong, or the heater relay is stuck.

The sensors need a 20,000 ohm setting. Faulty sensors can trigger pump operation.

  • Like 1
Link to post
Share on other sites
  • 2 weeks later...

So I replaced the circuit board and the thermometer yesterday. 

It now correctly kicks on the heater and pump 1 when heating, and shows the correct temp. 

I assume the mini fire we had from the married heater wires fried the board.

There were little warped edges around the board where the heater connected.

I've learned so much about that 10 year old hot tub at this point, thank you guys for all of your help!!!!!!!!!!!

1560702165_File_000(11).jpeg

Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
×
×
  • Create New...