Introduction
If you have reached this page, you have undoubtedly been looking for a solution for the E02 error that is showing up on your pump/heater unit, AKA the egg, that is preventing you from relaxing in your hot tub right now. In this guide we'll go over the many things that cause this error to appear. We'll then show you what you need to do to fix it. Keep reading and we'll have your tub back up and running in no time.
Getting Prepared
For the procedures you will be doing in this article you will need some basic tools to perform the tasks. A phillips #2 and flat head screwdriver. For some things it may be easiest to have a cordless drill with a screwdiver attachment. A set of small pliers, both standard and needle nose may help for some things. 
A volt meter that can check continuity may also be needed. You should also have your black caps for your water ports handy as it may be necessary to disconnect the egg when the tub is filled. These prevent water from flowing out when the hoses are disconnected.
In the steps outlined here, there are many causes that can be fixed without the need to replace parts. Some of the solutions listed however will require replacing parts. The order in which we will cover the listed solutions is to cover the basics that don't require part replacements first to rule them out first. This will save you from purchasing parts you don't need and getting your tub back in order the cheapest way possible.
Whenever working on your egg, be sure to unplug the power cord from the mains line when doing any service. Only plug it in when told to do so. This is for your safety and to prevent further damage to your egg.
Part of being prepared is knowing what you are dealing with. So what does the E02 error actually mean. The E02 error simply means that the egg is not sensing proper water flow through the water's path. A number of things can cause this. Let's go through them now. We'll start with the easy ones first. After each one of these procedures, plug in the egg and give it a test run.
First Things First
Let's start with the simple and most obvious things to get them out of the way. If you try to start your water pump with no water in the tub or with the water level below the filter inlets, you will get this error. This only makes sense since the E02 error indicates a problem with water flow. If there is no water there, it cannot flow. As long as the water is above the two filter inlet pipes and at least half way to the outlet pipe, you should be able to get water to flow. It is best though to have the water above the outlet pipe. WIth that out of the way, lets get into the other causes of this error.
Dirty Filters
Believe it or not, your filters being dirty can actually cause this error. A buildup of dirt and other things on the filters can slow the flow of water through the system. If the water slows enough, the water flow sensor paddle will not move enough to trigger the sensor to tell the system that water is in fact moving. One EASY way to tell if this is your issue is to remove the filter housings and start your pump. If it runs and doesn't give you the E02 error, this is your problem. Simply hosing off the dirt and junk from the filters can restore the water flow to a normal level. If the filters are too dirty, they may require replacing.
Clogged Debris FIlter
Another thing that can restrict water flow is a dirt and junk buildup in the debris filter that is on the output side of the pump directly above one of the filter housings. On some models it is the piece that your ChemConnect attaches to. Remove this piece and look inside. If you see a bunch of junk in there, it is probably restricting the water flow enough to cause the error. The easiest way to clen this is to back flush this with your garden hose. In some cases you may need a brush to get it clean. Then re-attach it to the liner.
Dirt Buildup on the Flow Sensor Paddle
Sometimes, depending on conditions, the water flow sensor paddle can get a buildup of dirt and debris on it that will prevent it from moving to the correct position when water is flowing. This paddle is supposed to lift up and trigger a sensor to tell the system that water is moving when the pump is turned on. Start by putting your black stoppers on all of your debris screens inside the tub and disconnect the egg. This requires you to remove both filter housings to put these stoppers on. Look inside the top hose connector and you should see the flow sensor paddle hanging down. If you can see dirt and debris around that you need to clean it. 
First, flush water through the egg in both directions to help loosen and remove any other debris that may be hanging around inside. To do this , run your hose into the top port on your egg for one to two minutes as seen in the picture. Then switch the hose to the port just below that one and do the same thing from that end. Now look inside the top port again and see if the debris has cleared. Once flushed, re-attach the egg to the tub and re-test. Remember to remove the black stoppers from the ports inside the tub. Forgetting this will DEFINITELY cause an E02 error.
Crushed or Kinked Inlet/Outlet Pipe
A crushed or kinked inlet or outlet pipe can be caused from different things. One reason could be that your liner is low on air. The main reason for this is usually due to a kink in one of the hoses that goes through the liner from the egg because of a sag in the liner. The loss of air will allow the hose to bend which will restrict the water flow. Simply fill your liner with air can straighten the pipes out and if that was the issue you should be good. Other things such as pipes going soft over time can cause this. Another option to solve this would be to get a short piece of rigid pipe to fit inside this pipe to keep it from collapsing. This may be helpful to do to both the top and bottom water pipes.the pipe should fit inside the gray end and be long enough to go through the liner but not come out the other side. This length can be different depending on your tub model.
Limescale Buildup
If you live in an area with hard water you are no stranger to limescale. A limescale buildup on things can cause a number of different issues.
If you cleaned out your debris filter in the previous steps and found white flaky bits in it, you most likely have a limescale problem. These bits can get on and into various things and cause problems. The image to the right, thanks to Dean Masters from the UK, is a heater unit that is caked with limescale. You can see how this could easily restrict water flow. One this bad in addition to restricting water flow can also trip the electrical line or the GFCI plug to your tub, which was the problem Dean was having. You may have heard of people talking about descaling their egg.
A simple descaler can be seen to the left. The square tube with connectors is attached to the pump inlet and outlet and filled with cold water just a bit above the top tube. You will then need some sort of descaling solution. These can come in powder or liquid form. A common brand is made by a company called Oust and is designed to clean coffee kettles, irons and dishwashers. Some other brands are lime-away and CLR. Putting a good bit of this solution in the descaler and turning the pump and heater on for 15 to 30 minutes will break up and disolve the limescale buildup and get you back running quickly. If you are getting the E02 error immediately after turning on the pump, you may want to let this descaling solution sit for about an hour to see if it breaks up a little bit of the lime to get things flowing. Once it is flowing and you can turn the pump on, let it run for the 15 to 30 minutes and you should be set. If you live in an area of hard water you should do this a couple times per year to prevent these problems.
Broken, Stuck or Damaged Impeller or Impeller Shaft
The impeller is the part of the pump that actually makes the water move. The motor spins this and the paddles push the water. There are a number of things that can fail with regards to the impeller, one being the impeller shaft. The impeller shaft in the image to the right is the pin that goes through the center of the impeller with the two small black caps on it. Many of the impellers used in the egg have an impeller shaft that is made of ceramic. These shafts have been known to break on occasion. When this breaks, the impeller will not spin freely and can lead to a decrease or complete stop of the water flow. If the impeller is moving with a broken shaft the egg can be very noisy and making a rattling sound.
Another thing with the impeller can be a rusty or damaged magnet. To the left is an example of a rusty impeller magnet. When a magnet gets rusty, it gets weaker. When the magnet gets weaker it cannot spin as efficiently, or at all. In this case you will need to replace the impeller. Some of these have the magnet encased in plastic like the one to the left, and some have the magnet exposed like the one shown above. Replacemtns can be found on ebay, amazon and other online stores such as headseal.com. Some of these kits will also include the rubber o-ring seals. If you are taking your pump apart, why not replace them. An ounce of prevention is worth a pound of cure.
Damaged Water Flow Sensor
These pumps are equiped with a water flow sensor to tell the pump that water is actually moving through the system. The water flow sensor is a tube that has a small paddle that contains a small magnet that hangs in the water's path, and when water flows through the tube, the paddle is pushed upwards causing the magnet to trigger a magnetic switch. When the switch is triggered, it indicates that water is flowing. The way the system works with this sensor can trigger not only the E02 error, but it can also trigger an E01 error.
We'll start with the E01 error. When the pump is turned on, it immediately checks this sensor for a split second looking to see that it is not triggered before turning on the pump. If the system sees that the flow sensor is triggered immediately upon startup, it assumes that the paddle is stuck in the up position. With the paddle stuck in the up position, the system assumes that it cannot accurately detect water flow and will display an E01 error. If this is the case, sometimes a quick smack, not too hard, to the side of the pump will get the paddle to drop into the normal position. Another thing that can cause this is debris being stuck in the sensor, but if you did the flush in the earlier steps, this should not be an issue.
Now back to the original E02 issue. 
There are a few things that can cause the sensor to not trigger the magnetic switch. One of the main causes of this is broken plastic around the magnet that causes the magnet to get wet and rust. As a magnet gets rusty, it gets weaker and if it gets weak enough, it can't trigger the sensor mounted at the top. If this is the case, the paddle will need to be replaced. You will need to remove the cover to access the sensor. 
Start by putting your black stoppers on the inlet and outlet ports on the inside of the tub and disconnect the pump from the tub. Once disconnected, remove the screws on the lip about half way up the pump. Slowly lift the cover off, but watch for the ribbon cable that is attached. You may be able to just set the lid aside with the ribbon cable attached. If you need to disconnect it for any reason, grab the black connector on the sides and squeeze it, then pull the connector apart. 
Once the lid is off, look just behind the top outlet pipe and you will see the water flow sensor. 
Remove the four screws on the top of the sensor and lift the top off being careful of the sensor wire that is connected to it and the rubber o-ring seal under the lid. There will be a pin through the side that holds the paddle in place. Push that pin from the side being careful not to break it, and pull it out. Install the new paddle and replace the pin. Move the paddle back and forth to ensure that it moves freely. Now inspect the o-ring seal to see if it is damaged or looks worn. If so, it is best to replace it. I sell kits that come with the paddle and seal in one package. I also sell just the paddle separately. Click here to see my store for both. Once you have the paddle replaced and the o-ring inspected/replaced, re-assemble the flow sensor being careful not to knock the o-ring out of place and screw it back together. DO NOT overtighten the screws as you may damage the housing which will cause the seal to be weak and leak over time. Replace the cover being sure to connect the ribbon cable if you had it disconnected. Then re-connect the pump to your tub and give it a test. You should be back running.
Conclusion
By following these steps you should have been able to resolve any issue that would cause an E02 error. I hope thisarticle helped you and got you back to tubbing again. If you find any errors or just have questions, you can contact me here. Happy tubbing to all.
