Review: Jacuzzi J-315 Hot Tub

We were in the market for a hot tub spa and decided on the Jacuzzi Model J-315.  Here are some things to consider when buying a hot tub, and our review of the J-315.

We looked at several different hot tub brands, both online and at local retailers. The problem with online shopping is the inability to try the actual spa you’re interested in. In effect you pay several thousand dollars for something sight unseen. That ruled out online sellers, even though their prices were a little cheaper, and also local retailers who didn’t stock the model we wanted.

It turns out that was a wise decision. Most models we did try at local retailers were unquestionably wrong for us. We found seats that were uncomfortable, difficulty entering and exiting the spa, cheap construction, and jets that stabbed us in the back as we sat in the seats. Imagine buying online or by special order only to find we couldn’t use or enjoy the spa.

We also wanted a small hot tub, and that presented a problem. Manufacturers offer mostly larger models and retailers only stock those larger models. We supposed the seat design would be similar across different models from the same manufacturer. But, the smaller tubs are also smaller in height so it’s difficult to guess whether we’d be comfortable in a smaller tub, based just on trying a larger tub.

They say you should do a “wet test” and bring your swim suit to actually experience the model you want. In practice, retailers only have one model filled with water for customers to use, and that’s usually the top-of-the-line, largest spa. Again, it’s not much use in evaluating the model you want.

We eventually decided on the Jacuzzi Model J-315. Although it is advertised as a 2 or 3 person hot tub, we can’t see room for a third person, unless they are a very close friend, or a child. The J-315 holds 210 gallons of water and is just the right size for our 10-foot by 16-foot screened porch.

There are three seats. The reclining or lounge seat has a hump that elevates your knees. It has the most jets, two large jets for your lower and middle back and four smaller jets aimed at your upper shoulders or neck. Two small jets are also positioned at your feet, one for each foot. If you’re short, you may have difficulty keeping your rump in the seat without floating upward. If you’re tall, the smaller jets won’t reach your neck unless you put your rump on the hump, which defeats the purpose of the lounge seat. This seat faces the filter compartment.

The seat beside the lounge seat has two large jets aimed at your middle back. This seat faces the third seat, which is directly across the tub. That seat has two large jets aimed at your lower back at your hips and one at the center of your middle back. Since these two seats face each other, if two people were to use them at one time, they both would have to sit cross-legged, or with knees up. However, we have found it is comfortable to sit sideways in either of these two seats, and prop our feet up on the wall adjacent to the lounge seat while resting the head on the wall without headrests.

Note that there are no jets that hit the legs or thighs, or the side or front of your body. All jets are aimed at your back, except for the two jets aimed at your feet in the lounge seat. When we use the spa, we tend to sit a few minutes in each of the three seats. This massages all the spots: Lower, middle and upper back. If you get too hot, you can sit on the hump of the lounge seat. Although not very comfortable, it does allow you to cool your upper torso while still sitting in the water.

The J-315 has only one water pump motor, but it runs in two speeds, high and low. (Other Jacuzzi models in the J-300 line have two pumps.) We tend to always use the pump on low speed. High speed seems to be too aggressive, but it’s good sometimes for variety. This of course depends on personal taste. If you can stand more aggressive jet action on your back, you will want to use the high speed setting. We don’t consider the spa too noisy at either pump speed.

We found there are actually eight combinations of massage possible by varying the pump speed, the massage action selector and the air controls.

With the pump on low, the massage selector at position A (combo) and the air control off, you get the most gentle massage action. We find this good for a nice quiet, relaxing massage, especially in the seat with jets aimed at the lower back. For a little more forceful massage, open the air control toggle to get an effervescent massage. For even more force, turn off the air control and move the massage selector all the way to position B or C (depending upon which seat you’re in). For the most force at low speed, now turn the air control on. With the pump on high, you can repeat the above combinations of massage selector and air control for four more combinations.

There is also a waterfall feature. We find this a little too noisy, and prefer listening to the birds in our backyard instead. You can adjust it to a small trickle or fully open. It’s more powerful with the massage selector in position B (lounge seat), and more powerful still with the pump on high speed. There are always some drops of water coming out of the waterfall even when off. The valve does not seem to close completely.

LED lights provide colorful lighting. Light comes from the waterfall, the Jacuzzi logo on the headrests and from one underwater light mounted on the sidewall. The cup holders are not lighted on this model. The intensity of the light has three modes, high, medium and low. You can choose from seven different colors. We like the red light on low intensity at night. It’s a low level light and easy on the eyes. Near white is our next favorite. There is also a high-speed blend mode where the colors change repeatedly, but we find they change too quickly and it’s distracting. There is supposed to be a low-speed blend mode, but this doesn’t seem to work on the J-315.

The air control toggle switches are somewhat non-responsive. You can press in, but sometimes the expected action doesn’t happen. That is, the air is not turned on as expected or off as expected. We have to press the opposite way and then press it again.

It’s interesting to note that the jets and switches are counter-intuitive. To open a jet so it is active, you turn the ring clockwise. To close a jet, you turn it counter-clockwise. To turn on the air control, you flip the toggle down, and to turn it off, you flip it up. I would instead expect to close a value by turning it clockwise, or to turn on a toggle by flipping it up.

Although our dealer said the hot tub cover was light enough to lift on and off, in reality it will be too heavy and bulky for some people. The dealer didn’t have any on the showroom floor to demonstrate for us. Incidentally the cover folds in half length-wise, not width-wise. You’ll want to factor that into where you’ll place the hot tub to allow room to slide the cover off.

As for ordering and delivering a Jacuzzi there are a few things to consider. Be skeptical of the local dealer’s quoted time frame. We were told 7 to 10 days for factory delivery, but it actually took more than three weeks. If you’re trying to juggle a schedule between deck construction, an electrician, and hot tub delivery, don’t count on any specific time frame.

It turns out our deck construction was delayed longer than our hot tub order. The dealer offered to “hold” the hot tub in their warehouse until we were ready for delivery. However, when we later visited the store, we saw our actual hot tub on display in their showroom. People could sit in it and potentially scuff and scratch the surfaces, etc.

The local dealer could not give us the user manual or site preparation guide at the time we placed the order. You’ll want to visit the Jacuzzi website to get digital copies of these manuals. They’ll help you decide where to place the hot tub and tell you what’s required for electrical connections. This is information you’ll need when getting estimates from electricians.

There are three options for electrical connections. It comes factory configured for 120V/15A plug-in connection. You can also choose between two 240V hard-wired connections, a 30A service and a 40A service. The heater will operate when the pump is running high-speed only when configured with the 240V/40A connection. If you want to keep the water heated when running the pump at high-speed, you should choose the 240V/40A option. That’s the option we chose.

The manufacturer and the dealer both downplay the cost of the electrical connection. Nonetheless, it’s an important factor in the total cost of a new hot tub. Estimates we got ranged from $750 to $1800. That’s in addition to the cost of the hot tub. This was to install a 240V circuit breaker in our existing electrical panel, run a 240V cable to the hot tub, and provide a switch box near the hot tub, which is required by code. Even if you choose the 120V/15A plug-in option, you need a dedicated 15A circuit. Our electrician mistakenly left his paperwork behind showing his cost of materials was one-quarter the price he charged us. So you’ll probably pay the same rate no matter which wiring option you choose.

We also suggest studying the section on electrical connections in the user manual or site preparation guide. Your electrician may have a difficult time understanding it and you’ll want to verify he’s doing it correctly. For example the diagrams in the manual are upside down and backward compared to the actual circuit layout when you open up the panel on the hot tub. If you choose 240V/40A option, just remember you want to match white wire to white wire, black to black and red to red. That means you must simply move the red wire from where it is, to the empty terminal so it can be mated to the incoming red wire.

Unfortunately Jacuzzi doesn’t make the red wire long enough to be moved to the empty terminal, so your electrician will have to provide a long enough wire. My electrician didn’t have a large enough spade connector so he connected a small segment of wire to the existing wire with a twist nut. That made me nervous. I’m not sure if stranded wire should be connected to a solid core wire.

Then be sure to remove the tiny jumper so the heater can run when the pump is in high-speed mode. You’ll have to hunt for it. On our unit, it’s at the bottom of the circuit board behind some wires.

You should also check that all wires are securely fastened in the control box. After our tub was delivered I found a small set screw on the deck. Before the electrician arrived, I noticed a couple wires were not screwed down tightly in their connector blocks and that set screw matched one that was missing. So it had fallen out of the control box when the tub was up on it’s side during delivery.

As for water quality, we were completely new to spa water treatment, having never owned a spa before. The local dealer simply told us to bring the bag of starter chemicals and a water sample back down to the shop after we filled the tub for the first time. We weren’t adequately trained on what chemical to use when, or how often. We finally figured it out on our own after the water went cloudy and we had a heck of time trying to clear it up again.

What we learned was, add the alkalinity increaser first until the alkalinity reaches the appropriate range. Then add the pH increaser or deceaser as needed. Add a calcium hardness increaser if required. Then add the chlorinating concentrate.

The dealer said not to add the alkalinity increaser, even though their water quality report indicated it should be added. We used a lot of pH decreaser with no effect, until we figured out the alkalinity has to be in range first. Even on subsequent water quality reports that indicate alkalinity increaser should be added, our dealer still tries to hide it with a sticker on the printout.

A maintenance dose of chlorinating concentrate should be added every day, which the dealer didn’t make clear. Then once a week or so we double the dose of chlorinating concentrate as a shock treatment.

We just recently drained and refilled our hot tub, which is recommended every three months. So far, after four months, the Jacuzzi J-315 has performed well. We like the size, it’s comfortable design, it’s quietness and it’s quality finish.