Why would the pump pressure be low?

Answer 1

Yes, check the impeller, I found a fur ball the size of a Baseball in mine, pulled it out, used a hose to clean it out, got some more stuff out, put it all back together, pressure came up to better than I have ever seen it, heat works great now! When diagnosing these things, keep it simple, I have a habit of "worse case senario syndrome", but have found there is usually a simple cheap fix and saves a lot of $$$ to the pool guy.

Theyre is normally only a couple of reasons why you would get low pump pressure. The main one is that your skimmer box filter is blocked or your filter before the pump. What I would suggest is clean out both these fliters and give your sand filter a good backflush and rinse. If the pumps performance doesnt increase your other problem maybe that your pool water level is low. If non of these things work or are the problem. The only other 2 options you really have is that you have a blockage in Plumbing or your pump is an old pump and needs replacing. The water going to the pump is usually blocked. Clean the skimmer and pump baskets. If the pressure is still low, then some of the leaves might have gone through the pump basket and into the impellar itself. I've seen this happen often with tiny needle like leaves. To check the impellar, turn off the pump and remove the strap which holds the pump to the pump basket. Take a screw driver and gently pry the seal plate apart. Clear out any debris in the pump impellar. Lubricate the seal plate and diffuser O-ring and reattach the seal plate to the pump basket. Prime and turn on the pump. If the pressure is still low, there could be a blockage in one of the lines going from the pool to the pump. There could also be a leak. Also, valves which adjust the settings (skimmer, drain, cleaner) could be off. The vac cleaner line is much more restricted than the skimmer or drain lines. A valve that is wide open on cleaner would produce lower psi readings than then the drain or skimmer are open I recently had this problem. When I bought my home the previous owner had a pool service. This was the first time that I had a sand filter. I feel like such an idiot. The problem was a VERY full "pump basket." I guess that's what it's called. I had no idea that there was a secondary basket hidden at the pump. Mine is not visible. Even when I went to my local pool store, they made no mention of it after I described the problem I was having. I finally discovered the blockage after I decided that maybe I needed to re-prime the pump. After taking off the seal. OMG.. It had turned to a nasty mulch. Happy to say everything is running great, and I didn't have to hire someone.

No one mentioned a closed faced impeller. Most of the newer pumps today have closed faced impellers. The veins will clog with stones, pine needles of all sizes, seeds and virtually anything that will get past the pump basket. You will need extremely long needle nose tweezers and/or a small prod tool to dislodge debris.

Ive had my pool for about ten years and always monitored the filter pressure and typically would watch it climb until of course it required backwashing. This year I watched the pressure lose about 8 lbs, typically running 15 after backwashing and was now running about 7 pounds. I finally got around to digging deeper into the problem and removed the filter basket (at the filter, not the skimmer) and felt inside the impeller. It was PACKED WITH PINE NEEDLES! I was able to slowly keep pulling more and more out and presto, back to normal pressure. Of course what makes me mad is that for a month the filter has been running very inefficiently as a result. the pine needles make their way through both the skimmer and filter baskets. If you have pine trees and have a problem, check this!

Also check the o-ring on the pump basket lid. If that is cracked, you will lose pressure