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Pool Pump Troubleshooting

Pool pump priming after spring opening If you are having problems with your pool pump, or trouble getting your filtration system going, then the troubleshooting steps in this article will help you to find the problem and get your pump primed and running. When you are searching for troubleshooting help for your pool equipment online, one of the challenges that you will have is that there are many similar conditions, such as your pump not working, that could be from a wide variety of different causes. For example, if you are having problems getting your pump running, and you just installed a brand new pump, then this would involve different troubleshooting steps than a pool pump that was running yesterday but today stopped working for some reason. The likely causes for, and solutions to, these similar problems would be totally different. This page will cover troubleshooting steps that apply to all pool pump situations but with specific reference to pools that have just been opened for the year.


This article is intended to help you troubleshoot the problem of your pump not working after you have just opened your pool for the swimming season after being closed for the winter. While these pump troubleshooting tips will also apply to other pump problems and situations, the advice on this page is specific to the common issues found with pumps when opening your pool after being closed for an extended period of time.


Before we start with troubleshooting the pump you need to have a decent understanding of the terminology for pool pumps and problems that a pump can have. There are a lot of ways that a pool pump will "not work". It could be that your pump does not prime, or it could be that your pump runs but something does not sound right. It could also be that absolutely nothing at all happens when you try to run your pump...no sound, no movement...nothing. Knowing a bit about the nature of your problem and the correct terminology for the issue will go a long way towards you being able to research your problem to find a possible answer.





Common Pool Pump Problems

When troubleshooting technical problems of any kind it is very important to get as specific as possible with the symptoms you are experiencing. It is not good enough to simply say that your pump is not working...you need more details about how, specifically, it is not working. These tiny details are going to be what leads you down the correct path to find your solution. Consider these common pool pump problems that you might be experiencing:


Pump will not prime - Priming a pool pump is the process where the pump begins to draw water from the pool and expel air from the pool plumbing system through the return lines into the pool. A pool pump that starts and runs, and otherwise sounds good, but does not seem to draw any water into it can be considered to have a problem with priming.

Pump will not turn on - A pump that does not turn on or make any noise at all when you turn the power on would be considered to have a problem starting. This is not the same as a pump that runs but does not draw water. This is also different than a pump that turns on but then turns itself back off in that the electrical supply seems to be working but the pump is giving no indication of this.

Pump turns off - A pump should not turn itself off and if yours is doing this then that is a problem that needs further investigation. A pump can potentially turn itself off after extended periods of running but can also manifest this problem as soon as you turn the switch for the pump on. The pump may make noise briefly before turning off, or it may be instantaneous as soon as you attempt to turn it on.

Pump does not sound right - There are a few different conditions that could result in a pool pump that just does not sound quite right. These can include a motor that sounds like it can not raise RPM (struggling) or can often include squealing, screeching or metallic humming noises which indicate worn components in the motor. There is also a condition where the pump will run but then experience a violent shudder or shake and you will hear a distinct change in how the motor sounds. This may repeat itself in a cyclic rhythm.


When you are having a problem getting your pump going it is important to figure out where your problem would fit into the descriptions listed above. Already we can start to formulate potential causes for your problem based on knowing precisely what symptom your pump has, and also by knowing that you are just opening the pool for the spring season. These are two big clues which give us a lot of potential things to look at to solve this problem.


Pool Pump Will Not Prime


So you have just opened your pool for the season and you are trying to get your system up and running...but the pump is giving you problems. You have identified that the pump will turn on, and run, and is not turning itself off, but it simply will not prime. This is by far the most common problem that pool owners will encounter in the spring after opening their pool for the season. There are a lot of different reasons why this might happen but if you take your time and check each of these one by one you will most likely find your problem.


Priming the pump - Priming your pool pump simply means to add water to it. This is a normal process for any pool pump that is located at a higher elevation than the water level in the pool. Every time you stop your pump and open your normally closed loop plumbing system, then the water in your suction pipes will gravity drain back to your pool. In order to prime your pool pump you need to manually add water to it to help it be able to draw water up through the suction lines. When you first open your pool for the year it will usually take more effort to prime your pump than normal. If you are used to adding a bucket of water to your pump and turning it on, or maybe not priming it at all during the regular swimming season, it could be that your pump just needs more water. Normally the pipes to your pool will not be completely dry. Even if the majority of water drains back to your pool you will probably still have some water trapped in the lines. When you first open your pool for the year this means that your plumbing lines are bone dry on the inside. It would be normal when opening your pool to need to prime your pump three times as much as you normally would during the mid-season.


You should add water to your pump, usually at minimum two gallons of water or so, and then close the lid and turn the pump on. You can let your pump run up to five minutes and if the pump has not picked up the prime by then you should shut it off to avoid overheating and add another two or three gallons of water to the front of the pump before trying again. Repeat this at minimum five times before you give up. That means at minimum 10 gallons of water being poured into your pump coupled with a total of at least 50 minutes of (supervised) run time to allow the pump to try to work through it. If you have completed these steps and the pump has still not primed then you can be confident that you are doing everything you should from a normal pump priming perspective and you should now consider the potential for another problem preventing the pump from priming.



1) Check that the water level in your pool is at least half way up the skimmer mouth and NOT below the mouth of the skimmer.

2) Check that you have removed the gizzmo or winterizing plug that was used in your skimmer & make sure weir door is not stuck.

3) Check and make sure you have removed the return port winterizing plugs as this would also prevent your pump from priming.

4) Check your suction side and return side manifolds to be 100% sure you do not have a closed valve dead heading the pump.

5) If you have a sand filter be sure to check the filter head and set it to the "filter" setting (not "closed" or "winter").

6) If you have a cartridge filter be sure that you have not reversed the in and out pipes when it was put together.

7) Double check that the pump lid gasket is lubricated and seated correctly on the pump housing.

8) Quite often O-rings for valves and unions will fall out during winterizing. Double check you are not missing any.

9) The plastic winterizing port plugs on the bottom of your pump may be loose or leaking. Tighten carefully to avoid breaking them.

10) A suction side leak has developed during winterizing. If you have any threaded connections these should be checked and redone.




If you need to test for suction side leaks then you can try running a garden hose over the suction side manifold and fittings while the pump is running. If there is a suction side leak then the water from the hose should temporarily resolve this just long enough for you to notice the pump working for a moment. You can also sometimes get similar results by using plastic bags which will get sucked into any leaks on the suction side of your pump.


If you have gone through each of these steps and you can still not identify why your pump will not prime then there are only a few possible reasons left. While it is possible that a pump would work daily until the end of the season, but then not be able to prime next spring, it is far more likely that the plumbing lines are compromised...usually with a leak of some kind that was either introduced or became worse over the winter. The only way to be absolutely certain of the condition of your plumbing lines would be to pressure test the suction lines and determine if they are leaking. If you have a crack or break in the suction lines anywhere you are going to have a pretty hard time getting your pump to prime...if at all. If you have gone through all of the steps above and your pump still will not prime then you are most likely looking at a blockage in the line, or more commonly, a leak.


One thing that pretty much every pool technician will try if they can't get the pump running would be to try to force water through the skimmer suction with a garden hose. While putting some water under pressure down into the skimmer suction might help you need to be aware that you do not want to cover the suction hole with your hand. You can feed the hose a few inches down into the suction port opening but avoid making a seal with your hand around the opening as the suction power from the pump is dangerously strong. If the pump were to pick up prime while you are covering the suction port with your hand there could be enough power in the pump to cause you to become stuck and very seriously injured. There exists a product called a "priming plug" or at least it used to exist. This would allow you to attach a garden hose to a winterizing plug and force feed water through the suction line all the way to the pump. I have not seen these for sale in decades now but if you know where to get one or how to make one then using the pressure from your garden hose to push water from the pool to the pump can be a great way to get a stubborn pump primed.


Pool Pump Won't Turn On

Pump difficult to prime If your pool pump won't turn on that means that when you flip the switch (or breaker) to turn on the power...nothing happens. If your pump is completely silent and does not shake, hum, trip the breaker or do anything else notable at all, then there can only be a few problems that cause this. The total lack of symptoms in this instance actually is the biggest symptom itself. There are only a few things that could potentially be wrong with a pump that does absolutely nothing when you turn it on.


Most of the troubleshooting for this specific type of problem involves testing the electrical voltages in various places. If you do not understand electricity, or are afraid of it, or are not qualified to safely test electrical values then you should certainly not attempt to diagnose electrical problems with your pump. If you fall into this category then you are limited to turning the pump on at the switch. If that does not work you can try investigating the electrical breaker that supplies the circuit for the pump for any obvious signs that it is off (for the winter) or has tripped out for some reason. If the answer is not obvious to you and you have reached the end of what you can safety troubleshoot yourself then your next move should be to contact an electrician or reliable handyperson who can check your voltages for you. At this stage you still either have a pump problem or an electrical problem and you need to be able to test voltages to know which of these you are dealing with.


When you are testing the electrical system of your pool pump you want to verify that you have power every step of the way. The circuit should leave the main electrical panel from your home and travel out to the pump location where often you will find another box, breaker or switch of some kind. If you can test at the pump and you have no power, then test at the next closest junction to see if you have power there and keep working backwards towards the main electrical panel until you find the place where the electricity stops. You could have a bad wire or connection somewhere, or potentially some damage to your electrical service to your pump from rodents or other causes. If you can test and have line voltage all the way to your pump, but your pump still will not make any noise, or move, then you have reached the end of how far you can troubleshoot this pump problem. The very next step for you should be to call the 800 number on the side of your pump and ask to speak to technical support. If you explain that there is voltage reaching the pump (tell them the actual number) however the pump is totally dead then they should be able to advise specifically what the problem and repair solutions are. Most likely you will find yourself replacing the motor at the least, or the entire pump at most if your pump is not young enough to warrant swapping the motor. If your pump is under five years old consider a new motor. If your pump is over five years old then upgrading your pump may very well be the best plan.


Please note other than testing to make sure the power is reaching your pump, you should avoid any component level testing or additional electrical diagnosis inside your pump past the point where the line voltage supplies the pump in the termination junction box.


Pool Pump Turns Off

If you have a problem where your pool pump turns off by itself, either right away or after a period of time running, this is a specific symptom that only has a few possible causes. Again, much like with a pump that simply will not turn on, most of the troubleshooting steps for this pump problem involve electricity and testing for values at the electrical supply and at the pump. Electricity and water are a very dangerous combination so you should never attempt to do ANY kind of electrical work or testing without being experienced in safe methods for doing this. It will not cost a lot to get a handyman or an electrician to do some simple diagnosis so it is well worth a few of your dollars compared to your health or safety. It can be stressful when your pool is not working, especially if there is an expectation that people will be swimming soon, or you want to prevent your water from turning green, but no pool problem is worth doing something even 1% dangerous so forget about electrical testing if you don't know how to do it properly and safely.



Pump turns off right away - If you turn on your pool pump and within 10 seconds (or even instantly) it turns off or trips the electrical breaker, then this could be one of a few things. The first question is whether the pump makes any noise or not when you try to turn it on. If your pump makes a humming noise and then trips out the electrical breaker then this is a very common problem. Older pumps with internal rust and older brushes can develop an almost short circuit when the brushes are seized in place or lack the strength to start the motor into movement from a dead stop. If the motor is humming and not able to start up normally then there is a huge current pull to the motor. This results in heat building and eventually the electrical breaker tripping to prevent the potential for a fire to start. When the circuit is cold you usually have somewhere between 5 to 10 seconds of humming before the breaker will trip out. During those few seconds when the pump is trying to start you can try using a soft rubber mallet and hitting the sides (not the back) of the motor section of your pump. Often times this is just enough force to jog the motor slightly which can break free the rust that is preventing the motor from moving.


There is a fine line between jogging your pump motor with a mallet and taking out your pool frustrations on your broken pump


You are not trying to break anything - just troubleshoot the problem. If you are one of the lucky people able to get their motor started this way then you are on a ticking clock. You might get another season out of your pump if you don't start and stop it often, but more likely it will be a problem every time you turn off your pump so you should immediately be looking into either service or replacement.


If you have an older single speed pump then in my opinion you should not spend a single dollar repairing it and should instead switch to a variable speed pump. Variable speed pumps are such a good idea and energy efficiency improvement over single speed pumps that it is actually becoming law in many areas that single speed pumps are no longer allowed to be sold, serviced or installed at all. If you need to learn more about variable speed pumps then you should start by reading these variable speed pump reviews.


If rust was your problem with your pump then you should most likely be able to stop the pump and start it again now that you got it going once. If you try this and your pump will not start again despite running just moments ago then it is most likely that you have a failed start capacitor. The good news is that a start capacitor is fairly quick and easy to have replaced and one of the few service items that I feel are worth the time and effort to do on an old pump to get some more life out of it. Gone are the days of rewinding motors but a start capacitor is a quick and easy visit for any service technician. Be warned that a capacitor holds electric charges and can cause serious shocks even after the power has been disconnected. Additionally, capacitors have a nasty habit of exploding if you hook up the polarity backwards so if you think that you need a new capacitor perhaps this is best left to pool service technicians and electricians.


Jogging the motor with a mallet is the fastest test for a stuck motor but probably not the best one. If you want to be thorough, or if hitting pool equipment with a mallet does not feel technical enough for you, then you can also spin the motor shaft or impeller to get similar results. The only difference is that when you spin the impeller either by hand, or with a screwdriver from the back of the motor, you need to do this with the power off. Tapping with a mallet is a little more dynamic in that you are jogging the motor while power is being applied.



Pool pump turns off after a while - If you have started up your pool pump and thought that everything went well, only to later discover that your pool pump is turned off again then there are a few things that you should check specifically. The first would be to touch the motor to see how hot it feels. If a pool pump gets too hot it will turn itself off (thermal overload protection) to prevent from starting a fire. At least it is supposed to do that however the electrical breaker only monitors for temperature from current draw and not temperature from friction in the motor. If you discover that you pump is off then the first thing you should do is check the electrical breaker that supplies your pump to see if it has tripped out.


A tripped electrical breaker can be in the "off" position or it can also be stuck in a middle, half-way kind of position. If this is the case then you would need to turn the breaker all the way off before you can try to reset it and turn it back on. While it is possible that some sort of freak electrical occurrence caused the breaker to trip out, more likely that your pump was drawing too much power for some reason and this caused the breaker to heat up and trip out. If this is the case then the breaker will likely reset once cooled and then run again for a while before overheating once more and turning off. If you want to learn more about how pool pumps overheat and what you can expect moving forward from a pump with these specific symptoms then you can head this article I wrote about why do pool pumps get too hot which I published in 2016 on this website. This article was later picked up and published by Aqua Magazine in April 2017. In a nutshell, if your pump runs for a period of time and then turns off you have started down a path that will eventually result in a dead pump (if not a pump fire) and you will definitely need to replace your pump.


The only other noteworthy thing worth mentioning for a pump that is tripping the electrical breaker is that you should differentiate between a tripped electrical breaker and a tripped GFI. A GFI (GFCI) is a ground fault (circuit) interrupter designed to essentially act as a hair trigger for amperage spikes. Current and voltage are inversely proportional so when one goes up the other goes down. When there is a short circuit, or ground fault in other words, then the voltage which is normally expressed as a potential difference of energy becomes zero. If voltage were zero, then this would technically make the current equal to infinity. Obviously this is not possible, but this is the electrical process that happens when a short circuit happens. The voltage drops to zero and the current races upwards towards infinity all within milliseconds. A GFI breaker is specifically calibrated to detect and disconnect when a sudden current spike is detected, or when current is detected through a grounding conductor where it should never be. Some pool pumps are installed on GFI protected circuits while some are not. Since a pool pump is a wet area it should certainly be protected with a GFI however this is not always the case. Since a GFI is very sensitive you can sometimes get a GFI that trips out from the slightest bit of dampness in and around the motor. GFI's can also become faulty themselves so it may turn out that the pump is not even the problem after all. Actually the same goes for regular household electrical breakers...they can simply wear out over time and replacing defective breakers would be considered every day work to residential electricians for this reason. If you have been using an electrical breaker as a switch to turn your pump on and off then this most likely caused the problem that you have now. Electrical breakers are NOT switches, and are not designed to be used as one, especially for controlling a large electric motor. This is what they make motor starting switches specifically for.


Pool Pump Doesn't Sound Right

If you have just opened your pool for the year and you went to turn on the pump but it is making a funny noise, then there could be a few different things causing this. The first thing you want to do is to identify the different types of noises that your pump might make so you can research the potential solution for each of these.


Humming pool pump - As discussed in the section above a humming sound coming from your pool pump usually indicates that the pump is stuck and not turning over either due to being rusted in place or from having a failed start capacitor. Usually a humming pool pump will only run for a new seconds before overheating and tripping the electrical breaker.

Bearing squeal - If you start your pump and for the first time you notice that it is making a new and strange noise, then you may be hearing metal bearings inside the motor that are making noise due to friction. Metal bearings will tend to sing, or scream, depending on how far along they are in terms of failing. Given enough time the bearings will continue to get louder and louder as the amount of friction, rust and heat all increases. If left long enough eventually your neighbors will let you know that your pump is too loud, or potentially your neighbors will let you know that your pump is on fire...which can happen. If you notice that your pump is making the distinctive bearing squeal noise then you can potentially have the pump serviced and the bearings and main seal replaced. For some people this will be the best option however the cost of a new pump is low and labor rates are high for pump service. If your pump is still fairly new, let's say under five years old as an example, then servicing the bearings may be the best bet. If your pump is in the seven to ten year range then you most likely should invest that money into a newer pump that will last longer. If you have just opened your pool for the year and discover this sound it is very likely that you can operate the pump for days, or even weeks longer, before the pump will get worse. This video shows a pool pump that has advanced levels of bearing friction and failure is imminent.

Sluggish or struggling pump - If you notice that you pump turns on, or at least tries to, but you can hear that the motor does not sound right then you may have a problem preventing the motor from spooling up to speed. The most common problem would be that the pump is only getting half as much power as it should. This is a very common pool pump problem that pool owners encounter when installing a new pool pump that comes factory wired for 240 volts on a 120 volt power supply. The pump turns on but sounds slow and sluggish. If you have a problem that sounds like this but the pump is not newly installed, then it is possible that the electrical circuit feeding the pump has tripped out only half way. Since 240 volts in a residential system is made from two opposing phases of 120 volts, it is possible that only half of your breaker has tripped out for some reason. Double check that the electrical supply for your pump is providing the correct voltage. If your pump is only 120 volts then it is not possible to be half way tripped like with 240 volt pumps. If you have a 120 volt pump that sounds sluggish and slow then I would consider bringing in an electrician to verify that there is not a problem with the wires supplying the pump, the breaker the pump is connected to, or the electrical connections inside the pump itself.

Pump shaking or making loud popping noises - If you notice that you pump seems to be shaking quite a bit or is making popping noises, or hissing and rattling noises or any kind of unusual noise that is repeating on a rhythmic cycle then you may be dealing with pump cavitation. Cavitation happens when the pump is being starved for water. When starved for water the impeller creates a low pressure zone and cavities, or bubbles, develop. As the bubbles pass through the pump they are forced to compress back into liquid, which results in a sudden implosion that is violent enough to physically shake the pump as well as cause internal damage to the pump. These shockwaves within the pump sound like popping from the outside, kind of similar to how it would sound if there were small rocks moving around inside of your pump. If you have pump cavitation then the first thing you should do is look into whether it is possible that there is an obstruction in the suction lines. If you have not done so, be sure to double check that the skimmer does not have the gizzmo or winterizing plugs still in place as this would certainly cause cavitation in the pump. A very common problem worth noting is that in the spring many pool owners will be doing heavy vacuuming with their systems. If you were vacuuming your pool for the first time of the year and now your pump will not run or is cavitating, then it is entirely possible that you have gotten something plugged in the suction lines. The standard process for blowing out stuck suction lines is to blow backwards from the pump towards the pool and never try to blow the restriction from the pool all the way to the pump. If you are doing any kind of heavy debris vacuuming in your pool you should always be sure to use a pre-filter of some kind such as this leaf canister to prevent blockages in your buried plumbing lines.


Troubleshooting Pool Pumps

I can certainly understand a pool owner who wants to do some preliminary investigation into problems they are having with their pool pump. If you let it, a pool will eventually bleed you dry financially, so pool owners need to be savvy about researching and solving problems on their own. There is something to be said about knowing when to call in a professional. This page is intended to give pool owners (and junior pool service technicians) an idea as to how pool pumps stop working, and how you can troubleshoot basic things with them based on the symptoms that they are giving you. If you have verified most of the information on this page and you are still not able to find the solution to your pump problem then you should probably consider paying a local reputable pool professional to come in and take a look at the problem for you.


Just as there is no problem with a pool owner becoming informed, or attempting to resolve and double check basic things about the pool and pump installation as discussed in this article, so to there is nothing wrong with calling in a pro who deals with these kinds of problems day in and day out. Swimming pools are more technical than many people assume and you should not be disappointed if you were not able to solve your pump issue on your own. This is the reason that professionals exist and sometimes there is simply no replacement for years of troubleshooting experience. Service technicians are likely to know about common issues with specific equipment, as well as more likely to notice a small or seemingly insignificant symptoms that you may have overlooked. If nothing else, the troubleshooting steps on this page have armed you to better understand the problem you have now as well as any future problems of this kind.





Swimming Pool Steve

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