Hot Tub Losing Water but No Leak? 4 Things to Check

Is your hot tub losing water with no sign of a leak? Hot tub leaks can be difficult to spot. But your spa could be losing water even without leak issues. This is even more frustrating because finding and fixing the problem can be even trickier.

Don’t worry – we’ll help you sort it out. Here’s what we’ll show you:

• Common reasons for water loss: Learn why your hot tub is losing water.
• DIY troubleshooting tips: Easy steps to identify and fix the problem.
• When to call a professional: Know when it’s time to seek expert help.

Ready to find your mystery leak? Let’s get into it.

Hot Tub Losing Water But No Leak? What’s the Problem? TL;DR

A hot tub losing water but showing no visible leak can be caused by natural evaporation, splashing and overflow, equipment malfunctions, or hidden leaks. Factors like temperature, humidity, user activity, and faulty components (valves, pumps, heaters) can lead to water loss. Regular inspections and maintenance can help identify and resolve these issues.

Common Misconceptions About Hot Tub Water Loss

Many hot tub owners assume that water loss always indicates a leak. However, this isn’t always the case. Natural evaporation, splashing, and even body absorption can contribute to water level decrease. Unless you’re really splashing about in a hot tub, the most common form of water loss will be evaporation. Let’s get into that one first.

1. Natural Evaporation

Every day, water will invisibly disappear from your hot tub. This is the most common culprit for water loss that leaves no visible signs. The only thing you can do about it is to cover your tub with a cover that sits directly on the surface of the water. 

Things that Increase Evaporation

There are really two things that affect water evaporation: what happens outside your spa and what happens inside it.

Outside your tub, hotter air that is moving more (think wind speed) will suck more water out of your spa than cold air that isn’t moving at all. Areas with high humidity will suffer less evaporation than places with “dry heat” like Arizona.

Inside your tub, hot water evaporates faster than cold water. Evaporation is also directly linked to surface area. So a bigger tub has more evaporation than a smaller one. Using your hot tub actually increases the surface area, so more use leads to more evaporation.

Normal vs. Excessive Water Loss

On average, you can expect your hot tub to lose about 1-2 inches of water per week due to natural evaporation. This rate can vary based on the factors mentioned earlier. However, if you notice water loss exceeding 2 inches per week, it may indicate a problem. 

How to Measure Evaporation

To accurately measure evaporation in your hot tub, follow these steps:

1. Fill your hot tub to its normal level and mark the water line.
2. Turn off all jets and ensure the cover is on.
3. Wait 24 hours without using the hot tub.
4. Check the water level and measure any drop.
5. Repeat this process for a week to get an average daily evaporation rate.

Multiply your daily rate by 7 to determine the weekly evaporation rate. Compare this to the normal 1-2 inch range. If it’s significantly higher, you may need to investigate further for potential leaks or equipment issues. Remember to consider environmental factors like weather conditions when interpreting your results.

2. Splashing and Overflow

This is an obvious one for all of us. If you are dripping water when you get out of the hot tub(and who isn’t?), then you’re carrying water out of the hot tub. Likewise, kids splashing water out of the hot tub are causing it to lose water. Simple stuff.

You probably cannot change how much water is lost due to user behavior without acting like Jim Carrey’s Jacuzzi Lifeguard. Of course, there are a few mild things you could do:

• Try to gently cut down on how much splashing people do. It’s a hot tub, not a splash park.
• Encourage people to get out via the steps instead of putting a leg over the side. This creates a slower exit, meaning less water is carried out of the tub.

That’s about it. Of course, if you’ve got a wooden deck then you’ll want to pay attention to how much water is on the deck and look out for potential water damage along the way.

3. Equipment Malfunctions

Problems in the equipment compartment with the machinery or electrical components could also cause water loss. These are more like leaks. Here are a few things to keep an eye on.

Faulty Valves and Fittings

Check your hot tub’s valves and fittings for signs of wear or damage. Look for cracks, loose connections, or corroded parts. Inspect the drain valve, as it may not be fully closed, causing a slow leak. Examine the pump unions and ensure they’re tight. Replace any faulty valves or fittings immediately to prevent further water loss.

Pump and Filter Issues

Your hot tub’s pump and filter system can contribute to water loss if not functioning properly. Inspect the pump for any visible cracks or leaks. Check the pump seal for deterioration, as a worn seal can allow water to escape. Examine the filter housing for cracks or loose fittings. Clean or replace the filter cartridge regularly to maintain optimal performance and prevent overworking the pump, which can lead to increased evaporation.

Heater Problems

A malfunctioning heater can cause excessive water loss through increased evaporation. Check the heater for signs of damage or corrosion. Inspect the heater’s connections and gaskets for leaks. If you notice the water temperature fluctuating or the heater running constantly, it may be working inefficiently, leading to higher evaporation rates. Have a professional technician inspect and repair your heater if you suspect any issues.

To identify equipment malfunctions:

• Turn off the power to your hot tub.
• Remove the access panel to inspect internal components.
• Look for wet spots, pooling water, or signs of corrosion.
• Check all connections and tighten any loose fittings.
• Listen for unusual noises when the equipment is running.
• Monitor water levels and temperature regularly.

If you’re unable to identify or fix the issue yourself, contact a professional hot tub technician. They can perform a thorough inspection and diagnose any hidden problems causing water loss in your hot tub.

4. Hidden Leaks

Even with proper maintenance, tiny leaks could develop. There won’t be any obvious signs, but there are a few ways to ensure you have timely detection of these pinhole leaks.

Detecting Small Cracks or Holes

Inspect your hot tub carefully for small cracks or holes. Check the shell, jets, and plumbing connections. Look for hairline fractures, especially around fittings and corners. Run your hand over surfaces to feel for irregularities. Pay attention to areas with discoloration or mineral buildup, as these can indicate slow leaks. Examine the pump, heater, and filter housings for signs of moisture or corrosion.

Dye Test Method

Use food coloring or a specialized leak detection dye to locate hidden leaks. Add a few drops near suspected areas while the pump is off. Watch for colored water movement, which indicates water flow. Test around jets, drains, and light fixtures. If dye is pulled into a crack, you’ve found a leak source. Repeat the process in different locations if necessary. This method works best for slow leaks that are difficult to spot visually.

Pressure Testing the System

Pressure testing helps identify leaks in your hot tub’s plumbing system. Isolate different sections of piping using valves or plugs. Pressurize each section with air or water using a pressure gauge. Monitor the gauge for pressure drops, which indicate a leak. Start with low pressure and gradually increase if needed. Check fittings, unions, and pipe joints carefully. Listen for hissing sounds that may reveal air escaping from small holes. Mark any problem areas for repair.

Remember to turn off power to your hot tub before conducting tests. If you’re uncomfortable performing these checks yourself, consult a professional hot tub technician. They have specialized equipment and expertise to locate hidden leaks efficiently. Regular maintenance and prompt repairs prevent minor issues from becoming major problems, ensuring your hot tub remains in top condition for years to come.

Maintenance and Prevention

Staying on top of any decrease in water level can help you keep your maintenance on point. This will lower the cost of hot tub maintenance in the long run.

Regular Inspections

Perform weekly checks of your hot tub to catch potential issues early. Examine the water level, ensuring it remains consistent. Look for any visible cracks, loose fittings, or damaged seals around jets and drains. Check the pump and filtration system for proper operation. Inspect the cover for wear and tear. Address any problems immediately to prevent water loss and more severe damage.

Proper Chemical Balance

Maintain the correct chemical balance in your hot tub to prevent excessive evaporation and equipment damage. Test the water at least twice a week, adjusting pH levels to between 7.2 and 7.8. Keep alkalinity between 80 and 120 ppm. Sanitize the water regularly with chlorine or bromine. Shock the tub weekly to remove contaminants. Use a water clarifier to improve filtration efficiency. Balanced water chemistry reduces the need for frequent draining and refilling, minimizing water loss.

If you’re daring, you could try to create a hot tub without chemicals. This takes a little more care, but is manageable and could be easier on your skin.

Cover Maintenance and Replacement

Your hot tub cover plays a crucial role in preventing water loss. Clean it monthly with a mild soap solution to remove dirt and debris. Apply a vinyl protectant every 3-4 months to guard against UV damage and cracking. Check for warping, sagging, or tears that could compromise its effectiveness. Replace the cover every 3-5 years or sooner if it shows signs of significant wear. A well-maintained cover reduces evaporation, saves energy, and keeps your hot tub water cleaner for longer periods.

There’s a difference between a top cover and a water cover, by the way. Investing in an inexpensive “bubble wrap” floating cover that sits directly on the water will reduce evaporation to zero when the cover is on.

When to Seek Professional Help

You should contact a professional if your hot tub is losing water rapidly or if you notice any of these signs:

• Wet spots or puddles around the tub’s base
• Unusual noises from the pump or heating system
• Sudden increases in energy bills
• Difficulty maintaining water temperature
• Visible cracks or damage to the shell or plumbing

These symptoms may indicate a hidden leak or equipment malfunction requiring expert diagnosis and repair.

Cost Considerations

Professional hot tub repairs can vary in cost depending on the problem’s severity. Expect to pay:

• $75-$150 for a diagnostic service call
• $200-$500 for minor repairs like replacing seals or small components
• $500-$1,500 for major repairs such as pump replacement or plumbing issues
• $1,500-$3,000+ for extensive repairs or full system replacements

While DIY attempts may seem cost-effective, improper repairs can lead to more expensive damage. Weigh the potential savings against the risk of further complications when deciding whether to hire a professional. You might even have to ask, “Is it worth it to repair the hot tub?”

FAQ

How often should I check my hot tub for leaks?

Regularly inspect your hot tub every month to catch any potential issues early. Of course, a quick look over for abnormal wet spots around the hot tub could also be part of your daily routine.

What is the normal amount of water loss for a hot tub?

Normal water loss due to evaporation is about 1-2 inches per week. This varies a bit, but most people work on 1/4″ per day.

Can a hot tub leak be fixed permanently?

Yes, most hot tub leaks can be fixed permanently with the right repairs and regular maintenance. Smaller leaks can be easily patched or filled. Larger leaks might need more extensive repairs, but should be manageable.

How can I tell if my hot tub cover is the cause of water loss?

If the cover is damaged or doesn’t fit properly, it can lead to increased evaporation. Inspect the cover for any tears or poor fits.

Is it safe to use a hot tub with a suspected leak?

It’s best to address the leak before using the hot tub to avoid potential damage and ensure safety. A very small leak is probably not a safety issue. But adding people and movement to a hot tub with a leak could make the leak worse.

Conclusion

If you’re constantly adding water to your hot tub, then you’re going to feel it in your wallet. Your water bill will be higher, the heater will run more (jacking up your electric bill), and the fresh water will need extra chemicals to keep it in balance.

You’re far better off keeping your hot tub in optimal working condition. Keep an eye on any drop in water level. Find the problem if it’s more than evaporation or splashing can account for. Then fix it. You’ll be able to enjoy your hot tub experience much more when it saves you money.

If you’re really stuck trying to find the cause of water loss, just visit your local dealer. Epic Hot Tubs can help you find the leak, give you some advice, and point you to licensed experts.

If you’re looking at a bigger problem and shopping for a new hot tub, check out the best hot tub for the money.

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About The Author:

Manny Brambila

Pool & Spa Expert

Manny has been in the Pool & Spa industry for over 15 years and is considered a pool, swim spa, & hot tub expert. He has been a Certified Pool & Spa Operator (CPO) since 2009 and worked 15 years in aquatic training and development for the largest pool chemical and customer care company. He also has been an outside consultant for the Pool and Spa industry in Chicago, New York and Los Angeles since 2018. In the past few years Manny has become Director of Operations for Epic Hot Tubs with a priority of providing customers with the most reliable information and best service possible.