Matthew
Jun 12
9 min read
There’s nothing worse after a hard day at work, looking forward to relaxing in your hot tub, only to open the cover up and find it cold, lifeless, and flashing a dreaded error code. But you need not worry! Most hot tub error codes are the result of your spa realising something isn’t quite right and shutting down to protect itself from further damage - and sometimes it’s the simplest of things!We’re going to list the most common error codes for troubleshooting Hydropool hot tubs and swim spas. Typical Hot Tub Error Messages Displayed on the Topside Control: OH - Overheat Error Message AOH - Internal Overheat Error Message HL - High Limit Error Message FLO - Flow Error Message
UPL - User Programming Language Error Message
Prr - Probe Regulation Error Message
Hr - Hardware Error Message
COMM - Communications Error Message
OH - Overheat Error
“The water temperature in the spa has reached 42ºC (108ºF). Do not enter spa water.”
I love getting into a nice warm hot tub as much as the next person but, it can get a little too hot. As a hot tub creeps above 40ºC (the maximum set temperature for a spa), it can become hazardous to our health, risking hyperthermia and dizziness. It can also be stressful for your spa’s equipment and plumbing at further use or heating can damage the inner workings, such as your pumps or heater.
An overheat error is most common on a hot, sunny day, even if you’ve set your temperature to well below 40ºC - especially if your spa is in direct sunlight. Hydropool hot tubs are so well insulated that on a day like this, they can need a little help to breathe.
If you find yourself with an OH Error, try the following:
- Make sure all cabinet vents are set to the open position to allow air to move through the cabinet.
- Top your spa up with cold water, ensuring it is filled to the correct level.
- Reduce your filtration cycles - running pumps create additional heat as they work, which builds inside the cabinet. Reducing the filtration will allow breaks for the cabinet temperature to drop.
- Leave the spa open for a while, heat can escape from the waters surface, cooling the spa.
- Create a shaded area for your spa - with a spa umbrella or gazebo.
Your spa should automatically take occasional temperature readings, and once the temperature has dropped back within the normal range, it will begin working as normal, and you’re free to use your spa again.
AOH - Internal Overheat Error
“The temperature inside the spa cabinet is too high, causing the internal temperature in the spa pack to increase above the normal limits.”
This is a very similar error to the OH code, except the high temperature has been detected in the cabinet only, and the spa has shut down to protect electronic equipment from being damaged.
The fix for this code is very similar to the above, try the following:
- Make sure all cabinet vents are set to the open position to allow air to move through the cabinet.
- If possible, open the front panel of your spa to allow for a quicker cool down.
- Reduce your filtration cycles - running pumps create additional heat as they work, which builds inside the cabinet. Reducing the filtration will allow breaks for the cabinet temperature to drop.
- Create a shaded area for your spa - with a spa umbrella or gazebo.
HL - High Limit Error
“The water temperature at the heater has reached 48ºC (119ºF). Do not enter spa water.”
Another high temperature error, this time localised to the heater - the water in and around the heater has become hotter than expected, causing the heating element to overheat and shut down the spa to avoid dry fire or damage to the spa pack.
This one is a little different and can be caused by other factors.
If you get an HL error, try one or more of the following:
- Ensure your hot tub is filled to the correct level. If the system is struggling to pull water in, or sucking air in, this could potentially cause HL issues.
- Put your hot tub into standby and remove your filter, clean if necessary. The clogging of your filter may slow the flow of water to your heater, causing overheating of water around it.
- Try running your spa without the filter, remembering to close all filter compartments as normal. If this resolves the issue, it’s probably time for a new filter - even though it may seem clean it’s clogged up deep within the pleats, impeding the flow of water.
- If you’ve recently refilled your spa, you may have an airlock slowing the water down. See the FLO Error below for more information on clearing this.
Finally, if the issue has not been resolved, your heater may be clogged, blocked, or have something caught inside it. This requires switching the spa off, removing the heater tube and checking for debris. If you are not comfortable doing this, give us a call, we can either talk you through the process over the phone or send an engineer out to check this issue for you.
FLO - Flow Error
“The system did not detect any water flow while the filtration pump was running.”
A flow (or FLO) error is the most common type of error for hot tubs and swim spas. The hot tub has detected that there is no flow of water (or a very weak flow) passing through the system, and has shut down to protect your circulation pump and heater, as the spa could be empty or have air trapped in the system.
Try the following troubleshooting tips for FLO Errors below:
- Ensure the hot tub is filled to the correct level.
- Make sure your filter is clean. If it is more than one year old, it may need replacing.
- Open your spa cabinet and make sure all valves and gate valves are in the open position.
A typical hot tub gate valve in the open position
Airlocks Contributing to FLO Errors
If you’ve recently refilled your spa, you may have an airlock slowing the water down.
Clearing an airlock is dependant on your hot tub model:
- For Serenity and Classic hot tubs, restart you spa by switching off at the mains. Then, once the hot tub starts up again, making sure all jets are open, turn Jet 1 on high for 10-15 seconds, then switch off for 10-15 seconds. Repeat this process until your see bubbles escape the system and your jets start working as normal.
- For Self-Cleaning hot tubs and swim spas. Restart the spa by switching it off at the mains, when the spa restarts, open the bleed valve on the top of your filter compartment. Then on your control panels go to Settings > Maintenance > Standby. Let your spa settle for 10-15 seconds and then press cancel. Repeat this process until you see bubbles escaping the filtration jets, and your hear air escaping the bleed valve. Once the bleed valve is spraying out water you can tighten it back up again.
If the problem still isn't rectified after trying the previous steps, there might be a clog or debris stuck inside the heater tube. To check this, you'll need to turn off the spa and remove the heater tube. If you're not confident doing this yourself, don't hesitate to call us. We can either guide you through the process over the phone or send a technician to inspect the issue.
UPL - User Programming Language Error
“No low level configuration software has been downloaded into the system.”
This isn’t one you would typically see as a user, and would usually only be on a new spa. But this error means the spa doesn't have the correct software installed to allow you to control it.
As with many technological problems, if you do get this error out of the blue, it’s always worth switching the spa off for 15-20 minutes, and restarting it to see if the issue resolves itself. If not, give your spa dealer or local spa technician a call.
Prr - Probe Regulation Error
"There is a problem with the regulation probe. The system is constantly verifying if the temperature probe reading is within its normal limits.”
Again, this is not a very common issue. If you find this happens to you, make sure you don’t have any debris caught up in the heater, as with the HL and FLO errors - and again, it’s always worth switching your spa off and on again to reset.
If the issue doesn’t resolve itself, get in touch with your spa supplier.
Hr - Hardware Error
“An internal hardware error has been detected”
Unfortunately, not much can be done about this one. An indication that something has gone wrong with the components of your spa pack - circuit boards, relays, fuses, and cables. We’d always advise giving the spa a small break by switching it off for around 15-20 minutes and the restarting it to see if this solves the problem. If not, you’ll have to get a spa technician in to take a look.
COMM - Communications Error
“Problem communicating with the pack, check keypad connections or update the pack software”
This can often come in a couple of forms - if you have a colour screen keypad, you’ll receive the above message after a period of “initialising”, or if you have a small digital display, your spa will be stuck in a loop - showing start up codes as the pack tries to initialise over and over.
Unfortunately, other than trying to restart the spa and hope for the best, there’s not much that can be done about this. It’s a rare software error, similar to the Hardware Error, that means your spa pack may have gone a little haywire and is now refusing to talk to the keypad. We’d advise getting in touch with your hot tub dealer or local technician.
So there we have it - there’s often a simple solution to the most common hot tub error codes, from no heating to no flow, sometimes they can be solved with something as simple as topping up the water!
If in doubt, get in touch with your hot tub dealership - they’ll often be able to help over the phone, or send somebody out to fix the problem. If we happen to be your dealer, take a look at our service pricing, then give us a call.
