Whilst I would agree the majority of pool pumps are too powerful for excellent filtration, the “power” is needed to corectly backwash the sand filter. Many domestic sand filters do not backwash very well due to inneficiencies in the laterals and poor backwash flow rates. It is advised that a flow rate of 45- 60m3 per m2 of filter. Most domestic filters are around 0.3m2 or there abouts so 13.5m3-18m3/hour this is necessary to expand the filter media by 20% to release the dirt. Not doing the backwash properly means more accumilation of dirt in the filter leading to issues at some point.
Another misconception is turnover rates, turning over the pool water once only filters around 63% of the water. Because filtered water is added to a pool of unfiltered water so it becomes a dilution.
Gage & Bidwell’s law of dilution gives us some expectations on how much water actually makes it through the filter. 1st turnover 63%, 2nd 86%, 3rd 95%, 4th 98%, 5th 99% of the water filtered. There are alternatives but they are all pretty close to one another. Personally I am happy with 4 turnovers per day and that fits nicely with the energy usage of my pool at 67 watts (0.09hp) which is a saving of around 91% over the original pool pump. The variable speed pump is ramped up for backwashing with the addition of air scouring to remove as much of the contaminents as possible but with minimal water usage. The work on this continues with the addition of my own design of filter, specifically designed to backwash better.
Its the bearings, if the noise is more than usual. If you want to do it yourself, you will need a bearing puller, and need to watch the appropriate YouTube videos. Bearings typically cost about 10 euros, but you will need to get them off first to measure the size. Get the best, they are not much more.
Not worth just doing the bearings if not replacing the seals at the same time. Could well have been a contributory factor in the failure. The commutator will also have done a lot of work.
Fitting a new pump be it variable speed or single speed with a variable speed drive would improve the water quality and save electricity which would pay back the investment.
Returning to this page because 4 years and a new pump later it is making a lot of noise again.
Just to add we had a new liner fitted end of March so I wonder if that makes any difference.
Obviously if we need another new pump I would like a more robust one.
I think the last one was from cash piscines, it’s a racer I think.
Check for debris in the impellor first, sometimes stuff gets stuck in there. Usually view it from the pump exit pipe.
Racer are the budget end of things but it could just be a bearing that needs replacing and thats just a few euros and some screwdriver work. Dont touch the ceramic bearing faces, this might be the ball race bearings.
Not really, Cash Piscines are excellent value but with that the possibilty of pumps not being the greatest quality. Things that dont have moving parts no problem.
I just purchased a pump last month that kept tripping out due to the thermal protection. Opened it up and the path for the water to cool it was completely clogged, now cleaned its working fine again.
Just back to this post.
My husband can’t find anything obviously wrong with the pump but it is loud but not whining.
A friend has got a Hayward RS11 30201, a year old, he says we can have. However is it too powerful for our 10 x 4 pool?
Any advise welcome. Thanks
I would say it is at 2hp and too expensive to run. I will take a look at the max rating for a speed controller, from memory they are for 1.5hp max but I will check.
Checking this morning 1 companies product is out as said too small but good news is Invertek E3 single phase to single phase should cover the size of pump. That means you can have a variable speed pump improving your filtration and reducing your electricity bill on filtration. Suggest you experiment to set up your backwash rate so you dont exhaust the sand from the filter, you would be looking for a 20% bed expansion on backwash. You could also use a flow gauge to set the correct flow rate for filtration.
Variable speed controllers work on a percentage level so you might set the pump to 65-70% for backwash and 20-40% for filtration. Depending on your flow gauge
I see.
We’re looking at Invertek now. They seem easier to buy in the uk.
We’re probably coming over in June so may wait as other than noisy the pump is working, it’s just how long?