![Rear Mounted Pressure Gauge](https://www.trevi.com/media/catalog/product/cache/0ba7bb27c380f29a001fb891254079e6/6/9/6940-manometre-pression-raccord-arriere_1.jpg)
Filters
Rear Mounted Pressure Gauge
I have in my hands a pressure gauge. This small tool allows us to read the pressure inside the filtration system. Ideally, it should be replaced yearly.
The pressure gauge works with the natural pressure of the pool. Take the pressure gauge reading when your filtration system and sand are clean or your cartridge is new or freshly cleaned. This is your new natural pressure. When the pressure rises 5 to 10 psi above your natural pressure, it's time for a good cleaning. If you have a sand system, do a backwash or if you have a cartridge system, clean the cartridge.
Today we'll look at how to change the pressure gauge. It's best to do it at the beginning of the season because the piping isn't connected yet.
Before screwing on the pressure gauge, use Teflon tape for a better seal. If you have to do the replacement during the season, take some precautions to avoid getting all wet.
Start by turning off the pump, then close the water access to the filter either before or after the filter. You'll do this if you're using a three-way or ball valve. With a cartridge filter, you must ensure that the valve on top is open to let the air out, or you'll have trouble unscrewing the filter. With a sand filter, you must put the filter handle in the Off position.
Now, you can unscrew the pressure gauge. There will be some residual water in the pipe, but that's normal. Replace it with a new pressure gauge that you will have wrapped with Teflon tape beforehand. By screwing in the pressure gauge right away, you will prevent the water from continuing to flow.
If you have a cartridge filter, the device is different. You'll have to remove the cover for the replacement. Here we have the valve and the pressure gauge. Both are tied with a butterfly nut under the cover. Locate the right one and unscrew it. Be careful when you unscrew and remove the old pressure gauge as there are gaskets. It will be critical to put them back in place afterwards. There is one here and a second one at the bottom of the cavity.
After removing the butterfly nut, remove the screw to replace the pressure gauge. Coat the new one with Teflon tape for a better seal. Put the whole thing back in place, screw the butterfly nut tightly, and put the filter cover back on. It's as simple as that!
View differents steps in this French video.