Hot Tub Frequently Asked Questions

You should do small checks and cleaning little and often, then book a full service regularly. For most hot tubs, a full service once a year is a sensible plan, especially before winter or before heavy use in summer. If you use it every day, or lots of people use it, you may need a professional check twice a year.

It’s always best to start by testing the water and adjusting it if needed, because good water care protects the pump, heater, and pipes. Check the sanitiser level and pH, and make sure the water level stays high enough for the jets to run safely. Rinse the filters with clean water, wipe the water line inside the tub, and look for anything unusual, like loud noises, slow jets, or small leaks.

Most people change the water every 3 to 4 months. If you use the tub a lot, you may need to change it sooner, such as every 2 to 3 months. Change it straight away if the water stays cloudy, smells strong, feels slimy, or becomes hard to balance even after testing and cleaning.

When the tub is empty, wipe the shell with a soft cloth or sponge and a cleaner made for hot tubs. Avoid rough pads because they can scratch the surface and make it harder to keep clean in future. Rinse well with clean water before refilling so no cleaner is left behind, then wipe dry to stop marks.

Rinse the cover with clean water, then wash it using a mild soap and a soft cloth, and rinse again. Let it dry fully before you close it, because trapped moisture can cause a bad smell and mould. Keep the cover clean and supported so it does not bend, and clear away rainwater or leaves so extra weight does not damage it.

If it is only for a short break, keep the water balanced, keep the cover closed, and run the tub on its normal cleaning cycle so the water does not go stale. You can also turn the temperature down a little to save energy, but do not turn it off if there is a risk of freezing. If you will not use it for a long time, drain it, clean it, remove and clean the filters, and make sure everything is dry before switching the power off, because leftover water can cause problems later.

Cloudy water is usually caused by tiny bits of dirt, body oils, lotions, or makeup building up in the water. It can also happen if the filter is dirty, the water balance is off, or the sanitiser level is too low to keep the water clean. Test the water, clean or rinse the filters, and run the jets and filtration for longer until the water clears.

A bad smell often means the water is not being sanitised properly, even if you have added chemicals. This can happen when there are too many used-up sanitiser leftovers in the water, or when the pH is out of balance and stops the sanitiser from working well. Always test the water, clean your filters, and consider applying a shock treatment, then keep the cover open for a while so strong fumes can clear safely.

A common pH target range is around 7.2 to 7.8, as this massively helps the water feel comfortable and helps sanitiser work properly. Total alkalinity is often kept around 80 to 120 parts per million because it helps keep the pH steady. Sanitiser targets depend on what you use, but many people aim for chlorine around 1 to 3 parts per million or bromine around 3 to 5 parts per million.

Use a hot tub pH reducer, which is usually a dry acid made for spas. Add a small amount at a time, with the jets running, and wait before testing again so you do not over-correct. Retest after about 30 to 60 minutes, then repeat in small steps until you reach the safe range.

Use a hot tub pH increaser made for spas, often based on sodium carbonate. Add a small amount with the jets running, then give it time to mix fully before you test again. If the pH keeps dropping, check the alkalinity too, because low alkalinity can make the pH swing around.

How often you add sanitiser depends on how much the tub is used, how many people go in, and how long you run the cover closed. Many owners test the water 2 to 3 times a week and add what is needed to stay in the right range. It is also sensible to test and adjust after heavy use, because the sanitiser gets used up faster.

It is usually best not to use household bleach because it can include extra ingredients, and the strength can vary. Some plain, unscented bleach is the same main chemical as chlorine, but it is easy to add too much by mistake, and it can upset the water balance. Using products made for hot tubs is safer and more predictable, and it helps protect the tub parts over time.

Foam is often caused by soaps, detergents, lotions, and body oils mixing with the water. It can also happen when the water is old, the sanitiser is low, or there are too many dissolved leftovers in the water. Rinse swimsuits well, ask bathers to shower before use, keep the water balanced, and change the water if foam keeps coming back.

Slimy water often means there is not enough sanitiser, so germs can grow and form a slippery layer. It can also be linked to dirty filters or build-up inside the pipes. Test and correct the sanitiser and pH, clean the filters, and consider a shock treatment or a pipe cleaner if the problem keeps returning.

Algae starts when sanitiser levels stay low, and the water balance is not kept steady. Keep sanitisers close and use them often, test the water frequently, and make sure filtration runs long enough each day to move water through the filters. If you ever see green patches or slippery walls, clean the shell, shock the water, and clean the filters straight away.

Scale is usually caused by hard water and high pH, which makes minerals stick to the shell and parts inside the tub. It can look like rough white or grey marks, and it may also reduce water flow if it builds up in the system. To remove it, lower the pH into the safe range, use a spa descaler made for hot tubs, wipe the shell with a soft cloth, and clean the filters, then consider using a scale control product if your water is hard.

You should rinse the filter every week or every two weeks, depending on how often the hot tub is used. If you use the hot tub a lot, or if several people use it, the filter can clog faster and will need more frequent cleaning. A deeper clean using a filter cleaner is usually needed about once a month to remove oils and build-up that a quick rinse will not shift.

Most hot tub filters need replacing about every 12 months, but this can vary by brand and how well it is looked after. If the hot tub is used heavily, you may need to replace it sooner, such as every 6 to 9 months. Keeping up with regular cleaning can help the filter last longer and keep the water clearer.

If the water stays cloudy even after balancing and cleaning, the filter may not be trapping dirt properly anymore. A filter that looks worn, has torn pleats, cracked end caps, or feels floppy instead of firm is usually at the end of its life. You may also notice weaker jets, longer heating times, or the hot tub showing a flow or pressure warning, which can happen when the filter is blocked or failing.

Turn the hot tub off before removing the filter so the pump does not run dry. Rinse the filter well with a hose, spreading the pleats gently so you flush out trapped dirt, and avoid high pressure because it can damage the filter material. For a deeper clean, soak it in a proper hot tub filter cleaner, rinse again until the water runs clear, and let it dry fully if the cleaner says to do so.

It is best not to run the hot tub without a filter because dirt can quickly reach the pump and heater. Without filtration, the water can turn cloudy fast, and the hot tub parts can clog or wear out sooner. If you must run it briefly for a test, do it for the shortest time possible and fit a filter again straight away.

This can happen if the water flow is too low, because most hot tubs will not heat up unless water is moving through the heater safely. A dirty or blocked filter is a very common cause, so rinse or deep clean it and check that the water level is high enough. Also, check the temperature setting, power supply, and any safety switches, and if the problem continues, stop using the tub and contact our qualified technicians.

Slow heating is often caused by a dirty filter, restricted water flow, or a heater that is not running at full power. Cold weather, a cover that does not seal well, or opening the lid often can also slow heating because heat escapes quickly. Clean the filter, keep the cover closed, and check that the hot tub is set to its normal heating mode rather than an economy or sleep setting.

Heat can drop if the cover is letting warm air escape, or if the water is losing heat faster than the heater can replace it. This can also happen if the hot tub is set to an economy mode that heats only at certain times, or if the water flow is not strong enough for steady heating. Check the cover fit, the mode settings, and the filter, and make sure the water level is correct and the vents around the cabinet are not blocked.

A heater or heat error usually means the hot tub has detected a problem with heating, water flow, or the temperature sensors. It may appear if the water is not moving through the heater, if the heater has overheated, or if a sensor is reading the wrong temperature. Start by turning the tub off, checking the water level and filter, then restarting it, and if the error returns, refer to the manual and contact a technician to avoid damage.

For most people, yes, it is best to leave it on so it can keep the water clean and maintain a steady temperature. Turning it off and on often can lead to stale water and can cost more because reheating from cold takes a lot of energy. If you will not use it for a while, lowering the temperature a little can save money while still keeping the system running.

Keep the cover in good condition and make sure it seals well, because most heat is lost through the top. Clean the filters regularly so water flows easily and the heater does not have to work as hard. Lower the temperature a little when you are not using it, use an economy or timed heating setting if your tub has one, and keep the hot tub sheltered from wind to reduce heat loss.

Weak jets are typically caused by low water level, a dirty filter, or a partly closed valve that is limiting water flow. Make sure to begin by checking the water level and topping it up so it sits above the recommended mark. Then rinse or deep clean the filter, and make sure any air controls and diverter valves are set correctly so water is directed to the jets you want.

Some jets may be turned off at the jet face, because many hot tubs let you twist a jet to open or close it. Dirt or scale can also block a jet, especially if the water has been out of balance for a while. Check that the jet is fully open, remove and rinse it if your model allows, and clean the filter to make sure the system has good flow.

A loud pump can mean there is air trapped in the system, the water level is too low, or the pump is struggling because the filter is blocked. It can also be caused by worn bearings, loose fittings, or vibration if the pump mount is not secure. Turn the tub off, check the water level and filter first, and if the noise continues after those checks, stop using the tub and contact us.

The pump may be turning off because it is overheating or because a safety system is detecting low water flow. A blocked filter, closed valve, or low water level can all cause this, and the hot tub may shut the pump down to protect the heater and pump parts. Clean the filter, check that the valves are open, make sure the water level is correct, and if the issue keeps happening, get the tub checked to avoid damage.

This often means there is an airlock, which stops water from moving even though the pump is on. It can also happen if a valve is closed, the filter is badly blocked, or something is stuck in the suction area. Turn the hot tub off, check the water level, remove and check the filter, and make sure all valves are open before restarting.

First, turn the hot tub off at the power so it cannot start whilst you are working. Loosen the filter housing or a pump union slightly, just enough to let trapped air hiss out, then tighten it again once water starts to seep out steadily. Turn the hot tub back on and check for normal flow, and if you still have no flow, repeat once more and consider asking a professional for help.

Some water loss is quite normal due to evaporation, especially when the water is hot and the air is cold. Some guides say that around 1 inch a week can be normal in the right climate and conditions. Splash-out is also something that can lower the level, particularly after a long soak with strong jets. A simple check is the “bucket test”: place a bucket of water on a step inside the tub, mark the water level inside the bucket and the water level in the tub, then check both after 24 hours; if the tub level drops more than the bucket level, you likely have a leak. 

Many leaks happen in the equipment area where you can reach the parts more easily, such as around the pump and heater. Common leak points include plumbing unions and fittings, plus the O-rings and seals that sit inside them. Leaks can also come from jet bodies, valves, the drain fitting, or small cracks in pipework, especially if parts have loosened over time.

First, you want to make sure you switch the power off at the mains before you touch anything, because water and electricity do not mix safely. Then, check if the problem could be something simple like splash-out, rainwater running off the cover, or a slow drip from a hose or drain point. If it is the result of any of these, make sure to dry the area so you can see if any fresh water returns. 

If you can access the equipment area, look for a steady drip around the pump, heater, and unions, and only hand-tighten a loose union if it is clearly safe to do so. If the leak is fast, the water level is dropping quickly, or you cannot find the source, stop using the tub and arrange a repair visit.

Leak sealer can help with small, slow leaks, but it is not the best choice for larger leaks or broken parts. Many products and instructions tell you to remove or bypass the filters before adding sealer, because the product can clog them, and you may need to clean the filters afterwards. Some sellers also state that the sealer should not harm pumps and heaters when used correctly, but you should still follow the exact directions and check your hot tub manual and warranty rules first. If the water loss is heavy or the leak is from a cracked part, a proper repair is usually the safer and longer-lasting option.

Costs tend to vary a lot with different companies because a simple fix like tightening a fitting is very different from a hidden leak under insulation. In the UK, most repair visits always start with a call-out or first-hour charge, often around £95 - £225, and then an hourly rate after that, depending on the firm and your area.

If parts are needed, or the leak is hard to reach, the price rises quickly, and one UK cost guide says leak repairs can be upwards of £1,000 in some cases. The best way to get a realistic figure is to ask for a quote after the leak has been located, because labour time, travel, and parts can change the total a lot.

This often happens when there is a fault in the electrics, such as water getting into a part that should stay dry, or a damaged cable. It can also trip if a part like the heater or pump is failing and drawing too much power. Switch the hot tub off at the mains and do not keep turning it back on, then arrange for a qualified electrician or hot tub engineer to check it safely.

The control panel may not work if the hot tub has no power, if the panel is locked, or if the panel connection has come loose. Moisture can also cause problems, especially if water has gotten behind the buttons or into the display area. Check the power at the mains and any isolator switch, then check for a lock symbol on the screen, and if it still does not respond, arrange a service visit.

An error code is the hot tub telling you it has detected a problem and has either stopped something or is trying to protect itself. Many error codes are linked to low water flow, overheating, a sensor reading, or a part not working as expected. The best next step is to check the manual for your exact model, then do the basic safe checks like water level and a clean filter before you try using it again.

Most hot tubs can be reset by turning the power off at the mains or isolator switch, waiting a few minutes, then turning it back on. This can clear any temporary fault, such as a small sensor glitch, yet be aware that it will not fix a real problem that keeps coming back. If the same error returns after a reset, stop using the hot tub and get it checked, because repeated resets can hide a fault and lead to damage.

You may find that the lights are turned off in the settings, or the hot tub is in a mode that disables them. If the settings are correct, the cause could be a failed light unit, a loose connection, or a blown fuse, depending on the model. Turn the power off before checking anything you can access, and if the lights still do not work, book a repair so the electrics can be tested properly.

Start with the basics, because the most common cause is a power issue at the mains, the isolator switch, or the safety switch that trips when it detects a fault. Low water level or a blocked filter can also stop some hot tubs from starting properly because they protect the pump and heater. If you have checked the power, water level, and the filter, and it still will not turn on, keep it switched off and arrange a professional inspection.

Yes, flushing the pipes is a good idea because dirt and oily build-up can collect inside the plumbing where you cannot see it. A sensible routine is to flush the pipework every time you drain and refill the hot tub, which is often every 3 to 4 months for many owners. You should also flush sooner if the water keeps going cloudy, smells bad, feels slimy, or if you see bits coming out of the jets.

Biofilm is a thin, slippery layer made by germs that can grow inside the pipes and other hidden areas, especially if the sanitiser level has been low. It can protect germs from the sanitiser, which is why water problems can keep coming back even after you add chemicals. To remove it, use a hot tub pipe cleaner made for flushing, run the jets for the time on the label, then drain the tub, rinse, clean the filters, and refill with fresh water before balancing the levels again.

Dirt coming out of the jets is often old build-up from inside the pipes, including biofilm breaking loose during use or after you adjust the water. It can also be linked to a dirty or failing filter that is not catching small bits or debris getting into the water from bathers, wind, or the cover. The best fix is to rinse or deep clean the filters, flush the pipes with a proper cleaner, wipe the shell, and then drain and refill if the problem keeps happening.

Hot tub water can get too hot if the temperature is set too high, or if the heater is not switching off when it should. First, lower the set temperature, take the cover off, and let the water cool naturally; do not let anyone get in until it is back to a safe level. If the temperature keeps rising on its own, switch the hot tub off at the mains and arrange a repair, because this can be a faulty sensor, thermostat, or control part.

Hot tubs are not recommended for very young children, and public health guidance for hot tubs says children under 5 should not use them. If older children are using a hot tub, keep the water cooler than an adult setting, stay with them the whole time, and keep sessions short so they do not overheat. A careful approach is to aim around 35°C to 37°C and get them out straight away if they look red, sleepy, dizzy, or complain they feel too hot. 

Irritation is often caused by water that is out of balance. This usually happens when the pH is too high or too low, or when the sanitiser level is not in the right range. It can also happen when the water is old and full of built-up waste like sweat, body oils, and lotions, even if you keep adding chemicals. Test the water, bring pH back into range, make sure sanitiser is steady, clean the filters, and change the water if problems keep returning. 

Green water is often algae from low sanitiser or poor cleaning, while green or brown tint can also be caused by metals like copper or iron in the water. Stop using the hot tub, test the water, correct pH and sanitiser, then shock the water and clean or rinse the filters so the dirt can be trapped and removed. If the colour does not clear, you may need a metal treatment and, in some cases, draining and refilling is the quickest fix. 

Keep the hot tub running and keep the water warm, because constant heat and circulation help stop freezing. Make sure the cover fits well, and keep it closed whenever you are not using the tub, as most heat is lost from the top. Check the water level and filters often, because low water or a blocked filter can reduce flow and increase the risk of freezing.

Switch the hot tub off at the mains straight away, and do not run the jets, because running a pump against ice can damage it. If you can safely access the equipment area, gently warm it using warm towels or a safe electric heater placed well away from water, and keep checking for melting. If you cannot restore normal water flow, or you see cracks or leaking as it thaws, contact a qualified technician before turning it back on.

In most cases, it is better not to drain it in winter, because an empty tub can still have water trapped in the pipes that can freeze. Keeping it filled, balanced, and running is usually the safest choice if you plan to use it at least sometimes. Only drain it if you are fully winterising it for a long break, and that means draining, flushing, removing water from the pipework, and keeping it powered off until it is ready to be used again.

Yes, you can use a hot tub in freezing weather if it is designed for outdoor use and it is running properly. Keep the cover closed as much as possible, because heat escapes quickly when it is open, and cold air can chill the water fast. After your soak, close the cover straight away and make sure the hot tub returns to normal heating and circulation, so it stays protected from freezing.

Look for a data plate or sticker on the hot tub cabinet, inside the equipment area, or near the control panel. It often lists the brand, model name, and a serial number. If you cannot find a label, check any paperwork that came with the hot tub, or search the manufacturer's website using the hot tub’s serial number.

Repairs are often worth it when the hot tub shell is sound, and the problem is a replaceable part like a pump, heater, or control item. Replacing the hot tub may make more sense if it has repeated leaks, major shell damage, or several expensive parts failing close together. A simple way to decide is to compare the repair cost to the price of a similar new hot tub, and also think about the age of the tub and how often it breaks down.

Many hot tub pumps last around 5 to 10 years, but heavy use and poor water care can shorten their life. Heaters often last around 3 to 7 years, and again, balanced water and good flow can help them last longer. If your water is often out of balance or your filter is often blocked, both the pump and heater may wear out sooner.

Small jobs, like cleaning filters, replacing a filter, and fitting simple clip-in items, are usually fine for most owners to carry out. However, anything involving electrics, heaters, control boxes, or water leaks is much safer with a professional because mistakes can cause shocks, damage, or flooding. If you are not fully sure what the part is or how it fits, using a professional is the safer choice.

Check the power supply and any isolator switch, and note if the hot tub trips again when you turn it on. Check the water level and clean the filter, because low water flow can cause lots of common faults. Write down any error code or message on the display, and note when the problem happens, such as only when heating or only when jets are on.

Always share the brand and model if you know it, plus the serial number if you can safely access it. It's best to explain the fault as clearly as you can, including any error codes, the things you have already tried, and how long it has been happening. Also, tell us the hot tub’s location, how easy it is to access the equipment side, and whether there is any water leaking.

A typical visit starts with a visual check of the hot tub, the equipment area, and any obvious leaks or loose fittings. Our hot tub engineer will usually test the water flow, heating, jets, and key safety parts. We then run thorough checks to find the cause of any errors. We will clean or advise on filters, note worn parts, and either fix the issue on the day or quote for parts if something needs ordering.

Some repair companies offer emergency call-outs, but it depends on the area they cover, staff availability, and the type of fault. We offer this service to our customers, so if you’re experiencing issues such as a fast leak, burning smell, or repeated power trips, we’ll be there to help as quickly as possible.