Smart Low-Flow Heater for Sundance/Jacuzzi 6500-310 5.5kW

The original (20-year old!) heater was still working until I installed a temp sensor incorrectly and accidentally dry-fired the heater. So I was very pleased to find this unit with a Hi-Limit Sensor included for the price. The one thing they don't say in the instructions is that the new high-limit sensor isn't supposed to seat all the way in as the old one does. But SpaDepot's support was great. They confirmed that it just needed to be caulked with some silicone to hold it in place. (See pics: old heater/sensor on the left, new units on the right.)
And, many thanks to John Reihing, who described in his review on this site how to keep from dry-firing it. Because of him, I was able to self-install with confidence.

My old heater started tripping my circuit breaker, so I checked the continuity of it and it was bad. So, I shopped around and found that SpaDepot had the best prices, by far, on a replacement.

The replacement arrived in great shape with good instructions. I watched a video on YouTube that helped me better understand how to disconnect the old one and connect the new one. The video was very helpful. I did the installation myself and everything seems to be working well. Overall, very pleased.

works great. easy to install and had plenty of extra parts for other models as well.

Easy install. Love the light indicators. Nice that it came with the correct adapters and the high temp sensor. Great price and SUPER fast shipping. Only bigger is that you need to silicone seal the high temp sensor as it isn’t a tight fit. No biggie though.

Perfect replacement. Easily installed. No more water leaks. Spa is up and running!

Exact replacement. Be careful - if the grounding rod moves it may leak, but some silicone sealer will fix it. I had the first heater replacement just before the 5 year warranty and the it barely lasted 2 years before leaking around the bottom element seal. I hope this one lasts longer. But installation was easy.

Installed it last week and appears to be working just find - solved my FLO problem as existing heater had so much calcium on it that calcium chips were flaking off and obstructing the heater flow.

it is just like the one l took out, easy to install and works great.

Good price and quality. The install wasn’t too difficult. The only problem I had was the two wires that went to the circuit board had a connector on them and I needed them separate so I could just plug them in the back of the existing 14 pin connector. The heater getting power indicator was a nice new feature that I didn’t have before.

Fit 2014 Sundance 880 Marin perfect. Took 6 hours to heat from 51f to 89f.

I have a 2019 optima 880. This heater was a perfect fit. Installing it was a bit trickier than what is in the video and comments. I needed an 11/32 (i think) wrench for the ground, my ground post spun with the nut, as did the heater posts. The vice grips only slowed the water leakage….. things were a mess. The upper heat sensor wires did not fit into the plug all the way so they were not making contact with the main board, i ended up removing the unused locking shroud. All in all it was a 1.5-2 hour job, start to finish. I will do this again as needed, i would just overprep before starting..

Ordered the heater after oem unit finally died after 20 years. Very easy install when following instructions and very glad they gave some new hose to connect both sides. Really like the additional indicator lights. Works just like clockwork and heats 5 degrees per hour.

The Spa Heater works great; delivery was excellent. It's much cheaper to buy it in the US and have it shipped to Canada. ☹️

Super fast transaction and best price around

Perfect replacement works great.

Matched perfectly, I arrived as expected and the customer service was helpful with the initial purchase as I had questions about the exact item. I am a do it yourselfer and the project was a job made easy. Plus I look like a hero to my wife

This product was just what I needed and it was so simple to purchase.

Super easy to replace the heater on my 20 year old hot tub. It's never worked better.

It is a heater in an older model hot tub.

easy install plus upgrades made like power light indicator and high temp limit switch indicator.

The part was perfect! Received it the next day after ordering it. Great service!!

Quick delivery, as advertised. Was able to get tub back up and running before it froze.

Great product easy to plug and play. I love the LED light comes on when the heaters on my previous original equipment did not have that.

Excellent customer service!

Replaced an original heater in an old jacuzzi. Worked fine for 29 months, then it started tripping the GFCI and has a 23Kohm path to ground through the heater. Warranty is only 1 year. Unfortunately there are not many choices for low flow replacements.

Works great, easy install.

Great product! Fast shipping!

Product was promptly shipped. Was very easy to install. Works perfectly. Would highly recommend.

The heater works and fits as advertised,got the heater in a couple of days am very satisfied with the product will use this company in the future.

Seems a little premature 2 rate a heater after only 2 months. But I will say that I'm very pleased. This is the third heater on my fifteen-year-old Sundance Cameo and running the Jets through their 20-minute cycle I,ve typically not lost a single degree of heat. Which is an improvement from the previous heater.