One of the toughest things about fixing a spa is diagnosing the problem. Not only are there many manufacturers, but each one now offers several different models. Every year brings new spas with the latest controllers and diagnostic mechanisms.

“In today’s world, when you’re fixing spas, you have to be an electrician, plumber and water-analysis person,” says Jim Gulla, co-owner and service manager of OJ Gulla Pools and Spas in Rome, N.Y.

To avoid common pitfalls, service technicians must first collect all the necessary information, sort through the basics and then pinpoint the culprit. Here, experts offer advice on how to diagnose a problem spa.

  • Initial investigation

Before you disassemble anything, start with the basics. That means taking a few minutes to listen to the homeowner.
“A lot of technicians don’t like talking to the homeowners,” says Douglas Dinkins, director of Spa Inspectors, LLC, in Houston. “Some think that by asking questions, they sound stupid. But you’ll show them that you actually are smart because you want to get to the problem.”

To save time and money for your client (and yourself), start with a preliminary screening. During the initial call, ask the customer to give a detailed description of how their spa has changed. “I ask, ‘What’s it doing or not doing that you’re concerned about?’” Dinkins says.

Prior to your visit, ask the owner to make some basic checks. For instance, if the customer says the high-limit switch tripped, the spa should be heated before you arrive. Then you can quickly measure how warm it gets before it shuts off. It beats standing around waiting for the spa to heat.

If the problem sounds simple, the customer may be able to pinpoint and repair it without a service visit. Otherwise, send a technician, and make sure it’s someone experienced in the area of the suspected malfunction. There’s nothing worse than a tech who isn’t familiar with the equipment.

Once on site, the tech should speak with the client, too. “You have to listen to them because lots of times a customer may say something that doesn’t make sense,” Gulla says. “But if you listen to them and put it in chronological order, then the problem will usually jump right out at you.”

It’s important to ask pointed questions, and don’t settle for vague answers. If you ask when the customer last cleaned the filter, it’s not enough to hear, “Recently” or “Don’t worry about it.” Evasiveness usually means they don’t know, Dinkins says.

Again, a couple of preliminary checks can help determine how the spa is used. Michael Durand first lifts the cover, which tells him all about the water’s chemical makeup.

“The discoloration in the cover will give me the entire history of the spa,” says Durand, owner of Classic Spa Service in Torrance, Calif. “When they have low pH, it burns the cover, so the center would be white. Then I go directly to the heater to look for any chemical damage at the heating point.”

In such cases, odds are the problem will reappear. Besides the immediate repair, Durand discusses spa chemistry and customizes a maintenance routine based on the owner’s usage.

Also, the filter should be checked early on. A clogged filter can cause a number of failures. If you suspect that a pressure switch needs replacing, for instance, it could be the filter’s fault.

“A pressure switch won’t turn on unless there’s enough water pressure,” says Todd Slasor, president of American Spa Services in Canoga Park, Calif. “Sometimes there’s not enough water pressure because the filter’s dirty.

“We would remove the filter cartridge and, if the pressure switch still remains off, then we know it’s the pressure switch, not just the cleaning [function],” he adds.

If the filter hasn’t been replaced in more than two years, change it — regardless of whether it turns out to be the culprit, Dinkins advises.

Finally, check for the simple things that aren’t always obvious. For example, older-model hot tubs include a magnetic interlock on the door. If the door isn’t closed, the spa won’t work. Durand has spent hours tearing apart a spa, only to realize the door wasn’t completely shut.

And what if you arrive when the homeowner isn’t around? Even if the spa looks fine, don’t just leave. Try to contact the customer so he or she can explain how the problem was solved.

  • No ‘parts jockeys’ here

There’s a term some spa-repair technicians use to describe colleagues who replace part after part until the unit works properly. They’re called “parts jockeys,” and many service managers discourage that approach.
“I don’t want my technicians to be parts jockeys,” Gulla says. “I want them to troubleshoot it correctly, be able to read blueprints and fix it correctly the first time.”

Constant parts replacement saves neither time nor money, many service pros agree. Customers may grow impatient waiting for this trial-and-error method to bear fruit. Meanwhile, the costs for unnecessary parts can quickly escalate.

Some techs will simply replace the problematic component. If the heater isn’t working, for example, they may just install a new one.

“But 50 percent of the time or more, it’s not the heater that’s not working,” Slasor says. “It could be some relay three or four switches back that’s just not giving the heater power.”

Or it could be a thermostat. Either way, zero in on the problem by following a pre-determined diagnostic protocol you’ve established for each basic set of symptoms.

For instance, if the GFCI trips repeatedly, Slasor starts by disconnecting the heater. “If the GFCI doesn’t trip now, then you know it was the heater,” he says. “But if it wasn’t the heater, then the next thing you disconnect is the air blower. If it doesn’t trip now, then it was the air blower that was causing it. But if it still trips, the next thing you do is disconnect the flow switch. So there’s a series of little things.”

Begin by checking the main component itself. Use a voltmeter or multimeter to determine whether the pump, heater, blower or another piece of equipment is receiving power. If it is, you’ve found your problem. If not, then a switch or relay likely isn’t transferring the current.

Depending on the symptom, you may want to consult an electrical blueprint for the spa, if one is available. Then you can see which series of switches and relays are involved. Next, work back from the main component, checking each relay or switch in the control box.

Certain areas are tougher to inspect than others. When confronted with a spa that’s more than a few years old, it may be difficult to tell when a circuit board is causing the problem or whether it’s the topside control.

The diagnostic mechanism will provide a code, but that could apply to either component. For such tricky diagnoses, Dinkins plugs in separate units to see if they work. “We have testing topsides,” he says. “So we can disconnect [the client’s] topside, plug in ours and, if we’re getting the same reaction, then it’s the board that’s bad. If it works with the new topside, it’s the topside that’s bad.”

In some instances, the problem may not be a faulty part at all. If the system doesn’t heat, it could be a restricted flow. Check the plumbing for leaves or other debris that may have caused a clog. This is often the case when a flow switch or pressure switch isn’t working. It may detect that not enough flow is moving through the heater and block heater activation. This also keeps the heater from burning out or catching fire.

If the unit contains a pressure switch, a little sand or dirt may also plug it up, preventing the heater from sensing the system pressure, says Phil Sandner, president of Easy Spa Parts in Oceanside, Calif.

  • Close it out

After the repair, Durand conducts a full diagnostic assessment of the spa. “I check the chemical balance, the heater terminal at the bulkhead fittings,” he says. “I check for burned wires. I [look at] every screw in the pack to make sure they’re all tight, make sure all the wire connections are proper so that when I leave a job, the system is pretty much bulletproof. I don’t want to change a heater and get called two days later and hear [that] the pump’s out.”
Dave Morris, senior service tech and warehouse manager at Mountain Hot Tub in Bozeman, Mont., is a firm believer in checks. His crews examine the air-check valves, jet selectors and buttons. It only takes a few extra minutes, but it’s worth the trouble.

Also, remember to test the ground fault protection during each visit. If you notice something that could cause another failure, notify the customer.

“These people use their spas to relax and forget about the worries of life,” Morris concludes, “so if we can give them some preventive tips along the way, they’re just going to be happier overall.”