Why is My Hot Tub Not Heating Up? (Easy Fixes)

One evening, I got back from work, and I was really tired. I decided to fix up a meal, eat, and after some time, get in my hot tub before I crawl into the bed to sleep. So I turned on the heater and I went to prepare what to eat.

About 90 minutes later, I decided to have a dip in my hot tub and I discovered the water wasn’t hot even though I switched the heater on about 2 hours prior. I was so disappointed but then I decided to find out why my hot tub wasn’t heating up. For anyone who might be experiencing the same problem, this was what I found out.

Different reasons could hinder a hot tub from heating up. It could be a burnt-out heating element, a glitch with the circuit board, a pest problem, a low flow issue, a faulty thermostat, wrong settings, or even low power voltage.

With so many possibilities, the most important step is to figure out the cause of the problem. When you narrow down the possibilities and figure out the cause, you can decide on how to fix it.

A heard this question a lot -- why is my hot tub not heating up? If you are having this problem then there are a few things that you should check. First, check your heater and see if it's working properly, then make sure to make a good water flow and good wiring.

Why is My Hot Tub Not Heating Up?

If your water gets heated to the required temperature, then the heater is working. If the water isn’t hot, too hot, or not hot enough, then chances are that the heater is not working well. This could be happening for different reasons such as:

A Low Water Flow

The heater in the hot tub needs enough water around it to work. If the heater isn’t getting enough water, it would shut off and it wouldn’t heat the water. A low water flow is likely caused by filth and dirt particles that block the water filter, the drain, or the pumps.

A Wiring Problem

A faulty wire could be the cause of the heater problem. Most times, there is a wiring problem because rodents have chewed the wires in the hot tub causing the heater not to work. A melted wire can also be the cause of the problem.

A Problem With the High Limit Switch

The high limit switch is a feature on the hot tub that prevents the water from overheating. The switch plays a regulatory role in the hot tub. A faulty high limit switch will cause the water to get too hot or hotter than required.

Related Read: How Long Does it Take to Heat a Hot Tub?

A Damaged or Wrongly Fixed Cover

Hot tub covers are designed to fit perfectly on the hot tub. If the cover isn’t placed correctly or the cover is damaged, it would result in heat escaping the hot tub and thus, you will have water that isn’t heated properly. This can also overwork the heater.

A Faulty Thermostat

A faulty thermostat can cause heating problems. Always check the thermostat to ensure it’s in good condition.

The Weather

If you live in really cold environments and you leave your hot tub open with water in it, the cold weather can cause the hot tub to freeze up. This can result in a damaged hot tub or a tub that has heating problems.

Any of these factors or a combination of more than one factor could be the cause of the problem. It’s important to figure out the precise reason or reasons your hot tub isn’t heating up well so you can take the right steps to rectify the issue.

Related Read: Do Hot Tubs Attract Mice?

How Do I Make My Hot Tub Hotter?

If you feel the need to crank up the heat in your hot tub, then it’s probably because of a faulty heater so you might want to check that first.

A heater in good working condition can heat the water in the tub up to 104 degrees Fahrenheit (40 Celsius). Most hot tubs have been designed not to get hotter than that and for good reason.

Inflatable hot tubs take up to 12 hours to heat up. If you are in a hurry, then you need to know how to heat inflatable hot tubs faster.

Submerging your body in water temperatures higher than 104 degrees Fahrenheit is not healthy nor is it ideal. If your heater is set at 104 degrees Fahrenheit, then that is hot enough for you. Do not attempt to get the water hotter than that.

Spend More Time In The Hot Tub

In fact, chances are you can’t handle water temperature at 104 degrees Fahrenheit but if you feel that water temperature is not hot enough, I would recommend spending more time in the hot tub rather than attempting to heat the water more than 104 degrees Fahrenheit.

However, if your hot tub isn’t getting to 104 degrees Fahrenheit, there are a few methods to crank up the heat

Turn On The Jets & Tweak The Circuit Board

Set the hot tub to the highest temperature and turn on the jets. The jets keep the water circulated causing the water to be heated evenly.

You can also bypass the hot tub’s heating limit by making a few tweaks to the circuit board. This can take the water temperature to as high as 108 degrees Fahrenheit. I wouldn’t advise this if you aren’t very familiar with hot tubs electrical set up.

Cover The Hot Tub & Install Insulation Boards

Cover the hot tub: By covering the hot tub, you are trapping the heat (or steam) inside. As more heat is produced, the tub gets even hotter because the previous heat hasn’t escaped.

Install Insulation boards: You can line the inside of your hot tub using insulation boards. Insulation boards will further help with retaining heat in the tub.

As a safety precaution, do ensure that you follow the specifications suited for your hot tub model, and remember, there are things like “dehydration” and “heat stroke” so don’t set the water temperature too high.

Related Read: How To Reset a Hot Tub Control Panel?

Can I Add Hot Water to My Inflatable Hot Tub?

As a safety precaution, do not add boiling water to the hot tub. Sometimes, we are tempted to add hot water to the hot tub to crank up the temperature. This will damage the lining of the hot tub.

Inflatable hot tubs are not built to withstand water temperature that is more than 104 degrees Fahrenheit and boiling water can reach 200 degrees Fahrenheit. That temperature can permanently damage your hot tub.

Related Read: Is It Safe to Allow My Hot Tub Run Constantly?

How to Heat Hot Tub (Without a Heater)?

A heater is the most convenient and safest way to heat a hot tub, but it isn’t the only way. What happens when you want to use your hot tub urgently and you find out the heater is damaged or burnt out? You can use one of the following methods.

Let Nature Assist You

You can use the sun to heat your hot tub by placing the hot tub under the heat from the sun. Though this is going to take so much time, it can work for you if you live in very hot weather conditions.

Rent or Buy a Mobile Heater

There is a wide range of spa heaters out there that can help heat the water in your hot tub in the absence of a functioning heater.

As a safety precaution, do not go for water heaters more than 180k BTU for inflatable hot tubs, and for regular hot tubs, keep it between 200k BTU and 250k BTU to prevent damage to the hot tub.

Pay to Have Your Hot Tub Heated

There are dozens of small and large-scale hot tub companies that render services such as heating your hot tub for you.

Though the heated water wouldn’t be hot for too long since there is no heating element to keep it at the required temperature.

It’s important to note that none of the methods above is a substitute for the inbuilt water heater that comes with your hot tub. If the heater is faulty, contact help to fix or replace it. 

How Do I Know if My Hot Tub Heating Element is Bad?

A heating element will burn out quickly if there isn’t enough water around it. The outer casing of the heater might also be cracked or corroded due to the acidity of the water. But how do you know if the heating element in your tub is bad?

Test The Heater

You need to test the heater with a multi-tester or test meter that will be set to read in “ohms.” You will place a probe on the test meter to each screw on the heating element. If the heating element is bad, it will give a very high reading or no reading at all. That means the heating element is either overheating the water or not heating it at all.

The normal reading of a hot tub heating element is between 10-12 ohms. Anything less or more than that will cause you to repair or replace the heating element.

Do a Regular Check Of The Whole Heating System

To keep the heating element in good condition, you are required to conduct a regular check and due maintenance on the whole heating structure. If you find out enough water isn’t getting to the heating element, then you should check the water filter.

Check For Dirt in Filters

It is possible dirt particles have clogged the water filters making it difficult for water to reach the heating element. This can cause it to burn out due to dryness. The heating element can also get corroded due to the effect of the sanitizers and chemicals used to treat the water.

Should You Change Your Heating Element & How Much Does it Cost?

If the heating element in your tub is damaged beyond repair or you have repaired it many times, then it’s time for a change.

The price to change the heater varies depending on the hot tub model you have, the price of the heating element, if you need to change just the heating element or the whole heater, and the cost of hiring a professional if you do hire one.

This is not a DIY task if you are not vastly experienced. A poorly replaced heater can cause a whole lot of damages to the hot tub and can be life-threatening too.

To change the heating element by yourself, you would spend about $30-$60 depending on the cost of a new heating element, but if you hire a professional, it can cost a few hundred dollars.

I hope you found this article useful. Let me know what you think below in the comment section. Also, if you have any questions, let me know too and I’ll answer them as soon as possible. Do have a nice day.

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