Hi. Ever since we moved in to this house in Plymouth MI in 2019, the Island Spas "Captiva" hot tub usually isn't working and needs repairs. It's a 2013 model, and the previous owner claimed he had no problems with it. But since 2019 we have had the heater replaced 5 times and the circ pump once. Currently the symptom is a "Heater is too hot" message and the water is cold. I finally fired our hot tub "repair" company (they would like me to buy a new one but I'd rather not) and it's time to start learning how to fix it myself. Let the learning begin...
Michigan (chronically broken) hot tub owner
- Thread starter markknopper
- Start date
- Jun 1, 2018
- 14,103
- Pool Size
- 26000
- Surface
- Vinyl
- Chlorine
- Salt Water Generator
- SWG Type
- Hayward Aqua Rite (T-15)
Let’s ring @RDspaguy 
In the meantime you can post some pics of the equipment area & find yourself a multi meter. I am sure he’ll have some questions/instructions for you.
In the meantime you can post some pics of the equipment area & find yourself a multi meter. I am sure he’ll have some questions/instructions for you.
- Jun 1, 2018
- 14,103
- Pool Size
- 26000
- Surface
- Vinyl
- Chlorine
- Salt Water Generator
- SWG Type
- Hayward Aqua Rite (T-15)
One other thing while we wait..
that’s alot of heaters to go through in a short amount of time. I see you have ozone - how are you sanitizing your tub?
can you share your latest test results
Fc/br
Cc
Ph
Ta
Ch
Cya
Salt (if applicable)
that’s alot of heaters to go through in a short amount of time. I see you have ozone - how are you sanitizing your tub?
can you share your latest test results
Fc/br
Cc
Ph
Ta
Ch
Cya
Salt (if applicable)
Last edited:
The #1 cause of heater damage is water chemistry, specifically low ph and/or high sanitizer levels, but scale resulting from high ph can also be a problem. Salt systems can also be problematic in some cases. I've seen the basic oem elements last over a decade, and I've seen them destroyed in months. Titanium elements can buy you some extra time, but they aren't immune either.
Typically a flow issue (filters/pump) but can also be a stuck relay under the right circumstances. Does the error occur shortly after you turn on power and before the pumps turn on, or randomly during operation?
Thanks for the reply. We did use a Saltron Mini when we first moved in to this house in 2019. I thought that might be the cause of the heater failures so I stopped using it and switched to chlorine powder only a couple years ago. Sometimes when we were using the salt system, the pH would be high and I used a ph reducer (muriatic acid I believe) a few times. So maybe that also produced scale and has clogged up the pipes reducing the flow to the heater? What is the best way to determine if that is true? How else can I test for low flow? Seems like it wouldn't be a stuck relay unless maybe an intermittently stuck one. Next time I get that error message "The heater is too hot", what should I do to try to track down the cause?
For the last ~2 years with just chlorine powder (sodium dichloro-s-triazinetrione dihydrate), the dipstick test has shown normal level of chlorine and normal pH. We are not heavy hot tub users, with just a 2-person household and we always take showers before and after using the hot tub.
I finally had time to mess with it today and I power cycled it. It is now in normal heating mode. The jets work fine. Temp shows 51 degrees and I have it set to 80 so all is well I guess until it breaks again, which could happen any minute.
I'm not too sure what all of those mean but the chlorine level and pH are normal (measured by the color on the dipstick). I'm not using salt any more. See more detailed reply to rdaspaguy. Not sure what you mean about ozone. Thanks, Mark.
- Jun 1, 2018
- 14,103
- Pool Size
- 26000
- Surface
- Vinyl
- Chlorine
- Salt Water Generator
- SWG Type
- Hayward Aqua Rite (T-15)
The strips are pretty finicky, generally inaccurate, & get easily bleached out.
do yourself a favor & get a proper test kit (Taylor k2006 or tf100) so you can manage your tub chemistry more accurately.
Definitions:
Br= bromine (sounds like this doesn’t apply to you as you mentioned you use chlorine as your sanitizer)
Fc = free chlorine
Cc= combined chlorine
The strips cannot tell the difference between these two as they only read Total chlorine which is fc+cc
Knowing them separately is pretty important as persistent cc’s mean its time to purge, drain, & refill.
Ph = potential of hydrogen (this should ideally be kept in the 7’s)
Ta= total alkalinity
Ch= calcium hardness
Cya = cyanuric acid- this is extremely important because it determines what your fc level should be
FC/CYA Levels
With solely using dichlor for chlorination your cya could be very high which makes proper sanitation hard to achieve. For Each 1ppm of fc that dichlor adds it also adds nearly 1ppm of cya. When cya exceeds 50 ppm in a hot tub it can be gregarious to keep sanitary.
What the strips say is “normal” may or may not actually be ideal.
We like to see the actual numbers.
Something isn’t right for you to be burning through heaters like you have been.
Have a read through our chlorine hot tub guide
How do I use Chlorine in my Spa (or pool)?
If you have a question about any information within this Sticky, please start a new thread for yourself where you will receive very quick responses to your specific questions. Thank you! Introduction There are two main things to consider when maintaining your hot tub water, Water Balance and...
www.google.com
Pool Care Basics
What Are My Ideal Pool Levels?
Use our tool to find ideal chemical levels for any swimming pool. Check TFP recommended levels on pH, free chlorine, cyanuric acid, and more.
www.troublefreepool.com
CYA Chlorine Relationship - Further Reading
www.troublefreepool.com
Scale is an insulator on the element. If you are getting a sandpaper feel in your spa you have scale.
The fact that it's random suggests strongly that it is flow related, though I have seen heavy scale and debris in the heater touching the element and sensor simultaneously cause this in rare instances.
Remove the filter until problem is solved. If it solves the problem get a new filter.
Remove and dis-assemble the circ pump to check the impeller for debris, scale, or corrosion. Circ pumps can and do overheat and shut off randomly when old, which would cause the error if the heater was on when it happened.
If it gives you the error a few seconds after you turn on the breaker then it's a stuck relay.
I can only help if you answer questions and follow suggestions.
The fact that it's random suggests strongly that it is flow related, though I have seen heavy scale and debris in the heater touching the element and sensor simultaneously cause this in rare instances.
Remove the filter until problem is solved. If it solves the problem get a new filter.
Remove and dis-assemble the circ pump to check the impeller for debris, scale, or corrosion. Circ pumps can and do overheat and shut off randomly when old, which would cause the error if the heater was on when it happened.
Knowing what the spa is doing, especially the circ pump, when it triggers the error is crucial.
Thanks for that info, could be helpful. The problem does seem random. Today everything is fine, the temp is correct and water is circulating normally. The circ pump was replaced earlier this year so it’s not old. I will remove the filters and see if that prevents it. I’ll also try to remove the circ pump and check for debris etc.
Just an update on this. The hot tub is working again. I had removed the filters for a few days and I checked the temperature and ran the jets for a while each day. No error messages, and the temp changes accurately with the setting (went to 100 and back down to 80). I have no idea if anything I did made it more likely to start working. So I suppose when/if it fails again I will restart the above process (remove filters, disassemble circ pump and check for debris etc.) to try to track down the problem. Thanks again for your comments and suggestions.