Hot Tub Filter Has No Suction!


Many hot tub owners tend to neglect their filters, causing them to become extremely dirty and sometimes not usable anymore, which leads to filters’ malfunction.

The clogged filter is the primary cause of dirty and turbid water because when your filter is full of dirt and other residues, it restricts water flow through it that can also lead to overheating and making your hot tub shut down. Therefore, you must maintain your filter regularly because when it becomes dirty, the filter will not remove the contaminants from the water, which will then go straight to the hot tub pump and damage it eventually. This situation will cost you even more than replacing the filter because changing a pump designed to work for several years is much more expensive.

Another possible reason for the filters’ breakdown is the loose installation. If you have ever wondered, the filter should not spin. If it spins, it means it is loose, and you should tighten it. A loose filter can cause water to bypass it and go straight to the pump, which leads to pump glitches and polluted water. However, the only part of your filter that should be moving is the floating piece called the weir door, which should go down when the jets are running to catch contaminants in the filter compartment, but when the jets are off, it goes up again.

Moreover, if you notice a glitch in your filter’s performance, you should check the filter pleats for any cuts and tears. They might not be instantly visible, but under the water pressure, they might widen, letting the water bypass the filter.

Inspection and regular maintenance prevent the filter’s malfunction, and you should be aware that the filter also degrades over time and should be replaced every 12 to 24 months.

What are common hot tub filter problems?

Almost every hot tub filter’s issue, either dirty, worn out, or damaged filter, stems from poor maintenance and neglect. 

CLOGGED FILTER

Irregular filter maintenance can cause contaminants, such as grim, dirt, body oils, and other residues, to clog your filter, leading to pump damage and shutting down the hot tub. In addition, the clogged filter prevents water from flowing effectively through the filter system, which results in dirty, unsanitary water, causing damage to the inner mechanical parts such as the hot tub pump, heater, sensors, etc. Moreover, if you notice that you have less power from the jets and that your water is not heated enough, it is an indication that your filter is blocked. If a clogged filter is shown as an error on the control board, and your hot tub will probably shut down.

WORN OUT FILTER

Filters are to be changed every 1-2 years; if not, they result in improper cleaning and sanitizing water. In addition, you should be aware that filter cartridges naturally degrade over time, causing the woven fibers to separate and not clean the tiny particles. Moreover, those fibers become coated with hard-to-remove oily contaminants causing them to clog the filter quickly. Additionally, over time filter’s plea become fuzzy, thus reducing the filter’s ability to trap pollutants because of the reduced space between pleats. The fuzzy texture of the pleats is also the cause of the turbulence in the water.

DAMAGED FILTER

If you doubt the filter’s proper functioning, you should inspect it for signs of physical damages, cuts, and tears. A filter is in the first line of defense against unsanitary water; thus, it can cause many troubles if damaged. A cracked filter is often a result of the small filter against an oversized pump. You should install a filter that is compatible with the pump and the size of the hot tub to purify the amount of water passing through it. Additionally, it would help if you inspected for any tears in the filter’s pleats which are only visible under high water pressure. 

In conclusion, it is proven that 80% of the filter’s problems are caused because of irregular and improper cleaning that can lead to damage that is much more expensive to repair.

How do I know if my hot tub circulation pump is working?

If your hot tub water is clean, evenly sanitized, has enough flow from the heater and jets, and more importantly, there is no unusual, loud sound coming from the hot tub, it means that your circulation pump is working as required.

The main task of the circulation pump, or the low-flow pump, is to circulate the water 24/7 to filter, heat continuously, and chemically treat the water. The water circulation process is slow and very quiet, producing humming or almost no sound at all.

The first indication of a circulation pump issue is the loud, gurgling, or grinding noise coming from the pump, usually caused by the limescale or clogged impeller. On the other hand, the cause of such an uncharacteristic sound can be a dirty hot tub filter, too. Limescale or the calcium build-up causes the circulation pump to work more loudly than usual. Luckily, this build-up can be successfully removed and dissolved using a stiff brush and CLR calcium, lime, and rust remover, which I found very effective and safe for plumbing. 

The loud and unusual sound coming from the circulation pump can also signify the bad bearings. The circulation pump consists of the two bearings whose assignment is to ensure smooth rotation within the pump structure. However, over time these bearings become worn out and start to produce sounds of shrieking and grinding.

Any other signs, apart from the unusual, loud sound, such as low water flow coming from the jets that can lead to poor filtration, heating, and chemical distribution, is an indication that there might be a problem within your circulation pump system.

Can you run your hot tub without filters?

Although running the hot tub without filters is not advisable, you can still do it just for a short time. Let me remind you that the filter’s central role is to clean and sanitize the water and prevent debris from getting into the pump. Hence, you have to be careful that nothing gets sucked into the plumbing because water goes straight to the pump without a filter. Running the hot tub without filters for an extended period could lead to the clogged pump impeller, and it would also reflect on the water’s quality.

However, when the situation occurs where you have to remove the filter from the hot tub, such as in case of cleaning and degreasing the filter, it would be best to power down your hot tub to prevent the possible damage to the inner mechanical parts. Therefore, my advice is always to have a spare filter that you can use to replace the one that is on cleaning. 

Additionally, if you decide to use and soak into the hot tub while your filter is out, make sure that you shower first before entering the water. Taking a shower will remove contaminants such as body lotion, deodorant, or other contaminants from your body. However, there is still a possibility of getting hairs into the water that could accumulate in the circulation system.

Running a hot tub without a filter would be a good thing if you drained and refilled your hot tub, but, I emphasize, only for a few minutes, not to get an airlock inside your plumbing.

Hot tub circulation pump clicks but won’t start?

Many of you have probably experienced the situation with a hot tub circulation pump that clicks when you turn it on; the jets start running for a few seconds and then stop. Moreover, sometimes when you turn it on, it does not start at all. There are a couple of things to inspect when this happens. The first thing you have to do is to identify the problem. The reason might be low voltage, a bad fuse, damaged power source, wiring, etc.

You should start from the power source, meaning that you should check the socket by pressing the GFCI reset button, which is usually positioned close, or try to plug the pump into another. If your pump is still not starting, check for any damaged wiring. Melted, burned, or tangled wires can cause an issue with the circulation pump start-up. 

The second step is to inspect the circulation pump plumbing because damaged pipes can lead to circulation pump glitches and cause the hot tub to shut down. 

If neither of these is the problem, then your circuit board at the pump receptacle is most likely not sending a proper voltage to your pump. Depending on the hot tub’s power, the voltage should be either 110-120 or 220 V. To test the voltage; you can use a voltmeter. Again, if you do not see the appropriate voltage, the problem is most likely the board, but if it is as required, the problem is in the pump, and you should inspect further.

Another possibility is the bad fuse or the motor capacitor. You should use a multimeter to test the resistance of the fuse. If it shows zero, the fuse is blown and should be replaced. However, the most common problem when the pump clicks but will not start is the bad capacitor, to be more precise, the start-up capacitor. When you inspect the capacitor, you can see it visually if it has become swollen or misshapen. Again, it would be best if you used the multimeter to check its capacitance. If the capacitor has failed, the readings would be much lower than rated.

To conclude, sometimes it happens that your circulation pump will not start simply because of the low water level. For example, some hot tubs have a safety switch that does not allow the pump to run until the water is above the jets.

Editorial Staff

I'm Adnan Sabanovic, the guy behind Hot Tubs Report. I've had a chance to enjoy hot tubs last few years and have really become interested in owning one of them. Nearly every weekend you'll find me spending time with my family or playing sports. If I am not doing that then I'm here writing about tubs on Hot Tubs Report. This blog is a research for my first hot tub which I decided to document and share publically so others can benefit from it as well.

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