High filter pressure after plumbing in SW chlorinator

[tyoder]

I have a sand filter that ran at 28 psi all last summer when clean, and would increase to 32-33 psi when dirty and flow would essentially stop until I backwashed. Then it came back down to 28ish, and flow would be back to normal. During the off season, I plumbed in a saltwater chlorinator between the filter and returns (no heater installed), and now when I opened up my pool and started up my pool pump, the pressure has increased to 45 psi. The filter is clean, I think, because the flow is pretty normal out of the returns.

I am worried, because the max working pressure on my sand filter is 50 psi, so I'm worried this is a bomb waiting to explode. Any idea of why the pressure would be so high after winterization, plumbing in the new SW chlorinator, and opening for this season? My first thought was the plumbing changed, but I dont see much more resistance in flow than how it was previously plumbed, that would make it go up by 20 psi.

 

[jblizzle]

That pressure rise does not make sense. Seems like there must be a blockage in the return path somewhere. You removed all the return plugs right

Can you post up some pictures of the equipment pad so we can see if anything looks off?

Does your SWG have union fittings? Can you pull the cell out and put a "dummy" pipe in its place to eliminate the cell as the problem?

 

[Bama Rambler]

Does the gauge go to zero when the pump is off?
Usually those gauges don't make it over winter, so it wouldn't surprise me if it's the problem and there's no actual pressure rise.

 

[jblizzle]

Does the gauge go to zero when the pump is off?
Usually those gauges don't make it over winter, so it wouldn't surprise me if it's the problem and there's no actual pressure rise.

Excellent question

 

[tyoder]

I didnt plug any of the returns. I drained the water slightly below the returns and skimmers for winter. The air pressure gauge does not drop to 0 when the pump is off; it only drops to about 40-41 psi. Im not sure how to post pics in my repsonse, so I attached a picture of the pad and plumbing, hopefully you can see it? I installed the plumbing so I can bypass the chlorinator if I want, which is what Im doing now. You can see the chlorinator isnt even in there yet, and the red squares show the valves are shut off so water doesnt flow down to where the chlorinator would be. The green box and arrows show the bypass valve is open and direction of water flow.

 

[linen]

As Bama instructed, if you gauge is only going to 41 psi when pump is off, it is broken and needs to be replaced. It should read 0 when pump is off. Seems likely your pressure is fine, but you do not know cause of the gauge.

 

[tyoder]

Should it read 0 though when the pump is off? Because technically, it is a sealed system, so as long as there are no air leaks, it doesnt seem like the pressure should drop, because the whole system is still sealed and pressurized.

 

[Buford]

Yep. My last gauge was $11 at the "pool store" you might do better elsewhere.

 

[jblizzle]

Should it read 0 though when the pump is off? Because technically, it is a sealed system, so as long as there are no air leaks, it doesnt seem like the pressure should drop, because the whole system is still sealed and pressurized.

Yes it should go to zero because it is not a sealed system .. the pool (and returns) are open to the environment.

 

[tyoder]

That seemed to do the trick. I took the gauge out, and it still read 38 psi once completely disconnected, so it was definitely faulty. I got a new gauge for $6, and now it is running around 8 psi. Thanks for all the help. I love this site!

 

[JohnT]

I generally pull my gauge and keep it in my sock drawer over the winter. Even with a roof over my equipment, my gauges never last through the winter if I leave them installed.