Diagnosing and fixing return jet problems can be one of the most annoying things when it comes to pool maintenance because more often than not, it’s something that’s pretty simple, but diagnosing it can become a pain since there can be a number of things that can be causing your return jets to become sluggish. To make it easier, we’ll be grouping the possible problems into two: namely low pressure readings and high pressure readings on your filter’s pressure gauge.

The first part of the equation is simple enough to determine, if the return jets are dribbling, then that’s your low return jet pressure. The other half of the equation is if the pressure gauge on your filter is reading lower than its “regular” or “clean” reading then you have a problem with your water source.

• Low pool water level - now this is the most common cause of low pressure coming from your return jets. Obviously, if there’s a low supply of water coming into your pumps, then there would be less water flowing through your filter, and ultimately low water flow from your return jets. The problem is quite simple to fix, simply raise your water level to about halfway of your skimmer box then you should take care of the problem quite easily. Note: Having low water levels can lead to your pump burning out, so if you notice your return jet being sluggish, treat that as a symptom of something that needs to be remedied ASAP! To avoid this problem, we recommend getting an automatic water leveling device so you’ll never have to think about your pool’s water levels again.

• Stuck weir doors - We did say that the causes were so simple right? Sometimes a stuck weir door can prevent water from freely entering your skimmer boxes and may lead to decreased flow of water to your pumps and filters, and in turn causing low return jet flow.
• Full pump and skimmer baskets - Again, another simple cause, check your skimmer basket and pump basket and empty them. Sometimes things like leaves and other debris can slow the water flow enough to cause low pressure problems for your return jets.
• Leaky fittings and O-rings - These problems can cause air to get sucked into your pump causing a drop in water pressure, check your valves, pipe fittings and your pool pump’s O-rings to ensure that there are no visible leaks. A way to diagnose this is to observe the water coming from your return jets, if there are bubbles coming from your return jets along with the low pressure then that’s a good sign that you have an air leak somewhere in between your skimmer box and your pool pump.
• Clogged intake lines - now things are starting to get complicated. If your water levels are fine and everything else looks to be good, no bubbles coming from your return jets, then you may have a clog somewhere in between your pump and your skimmer box. To deal with clogs, refer to our in-depth guide on how to deal with pool line clogs.

• Clogged or cracked impeller - this is the final thing that may cause low return jet pressure and one of the trickiest ones to fit. If it’s a clog, then you can try to fish out the clog with a piece or wire or if you have small hands (just make sure to power down the entire system first!). If you have a cracked impeller then you will need to replace it for your pump to be back in working order, refer to one of our guides here or here on how to take your pump apart in order to be able to access your impellers.

Now this may sound like a contradiction, but in truth, this is one of the easiest problems to fix. If you have a high pressure gauge reading then a good backwashing of your sand filter or give your cartridge filter a good rinse. The dirt and debris accumulating on your filter elements could be giving the water a hard time flowing out to your return jets.

Cleaning your filters should normalize the pressure and you should be seeing an improvement on your return jets pressure. Now if it doesn’t then you’ll need to consult with a pool professional to detect if you have a leak in between your filter and your return jets! To know more about pool leaks, click here.

The fixes and diagnostic tasks posted above should be more than enough to help you determine and fix the return jet pressure problems! Note: If your pressure gauge doesn’t change readings no matter what you do, there’s a huge chance that you’re just dealing with a fauly pressure gauge. Don’t worry too much though, you don’t need to replace your pool filters as pressure gauges are fairly cheap and they’re easily replaced.

We also have another guide here on how to identify and fix filter pressure problems which you can check out here.

Also, check this blog post about swimming pool repairs that shouldn't be delayed.