Hayward EC40 with 1hp Hayward pump - Flow slows over time

[marsui]

I have been having issues with my pump/filter all season. It's a used pump/filter I got from a friend that he had for about 20 years. Here is what happens.

When I run the pump for an extended period of time, the flow rate drops significantly. There are a few things I can do to restore the flow rate.

1. I stop the pump for like a few seconds, and restart it sometimes that works. I also open the air release screw after I turn it back on, sometimes that will work for a few hours, sometimes the flow rate drops again, in another 30 minutes.

2. I regenerate the filter, which I shouldn't have to do since I just put all new DE in (stop the pump, move the bump handle down slowly, lift up quickly 3 times as it states right on the DE filter).

Whats odd is I Just backwashed the filter 3 days ago (really really well, I made sure to get every ounce of old DE out,following the instructions on the filter). I added 4 lbs of DE into the skimmer slowly (as stated on the filter) after backwashing.

I don't understand why the flow rate keeps dropping, its very powerful when it works. It just keeps losing its flow rate for whatever reason.

Final notes, the pool has never been green, not once all season, I've been using clorox bleach every single day and the water is generally crystal clear to very clear, the water is also perfectly balanced, I test every single day so I'm positive its not built up dirt.

The pool was professionally installed only 1 month ago, all PVC plumbing. I made sure that air is not being introduced into the skimmer, however one thing I notice that when the flow rate decreases, the little skimmer trap that is attached the pump doesn't have water up to the cover, I think its because its just not moving water fast enough to fill it up.

I did read something about something within the pump that could need replacing, but I have no way of knowing if that is the case.

 

[Isaac-1]

Are you weighing the DE or just using one of those orange scoops? You should weigh it, those scoops can easily be off by 20% which may cause over coating. Alternatively the filter may just be doing its job and removing lots of junk from the water.

 

[marsui]

Are you weighing the DE or just using one of those orange scoops? You should weigh it, those scoops can easily be off by 20% which may cause over coating. Alternatively the filter may just be doing its job and removing lots of junk from the water.

Yes I used an orange scoop. I will fill the scoop and weight it as soon as I get home today to verify.

 

[marsui]

Yes I used an orange scoop. I will fill the scoop and weight it as soon as I get home today to verify.

I measured the weight, it is almost perfectly 1lb.

I turned my filter on at 4 today, by 5 my DE filter was filled with alot of air. The flow rate was reduced, pressure was unchanged however, and if I turned off the pump, open the bleed screw, turn it on, the flow rate returns, overtime again the EC40 fills up with air. I'm not sure what is causing this.

 

[Isaac-1]

It sounds like you may have a suction side air leak somewhere before the pump, this may be at the pump itself (drain plugs, cover gasket, plumbing) you can try using shaving cream or water from a hose to isolate where the air is getting in.

 

[marsui]

It sounds like you may have a suction side air leak somewhere before the pump, this may be at the pump itself (drain plugs, cover gasket, plumbing) you can try using shaving cream or water from a hose to isolate where the air is getting in.

Since the plumbing was all brand new this year, I would hope its not that. I'm not too familiar with the various components of the actual pump as this is the first year using it. I checked the cover of the leaf trap, it looks ok. Maybe I could try the gasket on the cover to the leaf trap? It's not a screw on, its one of the ones that you push down, and turn slightly to lock into place.

Is there a drain plug on most pumps? Mine is a hayward power-flo LX SP1510-z-1-XES

BTW is it at all possible that the DE filter "fingers" need to be replaced? Or would that not cause air to be introduced into the system?

What about the gasket on the DE filter? It does leak a little, I was trying to wait until the end of the season to replace since I have to take everything apart to see which gaskets need replacing.

Thank you

 

[Isaac-1]

I am not sure what you have going on, I when the flow rate goes down, and the pressure does not rise, is there then air in the pump stainer basket? If not I would begin to suspect you may have a bad pressure gauge where the needle sticks once it gets to a certain point and you are actually have a pressure rise.

 

[dsmith99]

Is this an in ground or above ground pool?

Suction side leaks are unlikely with an above ground as the water will have head pressure all the way to the pump. What can happen is simply not having enough water in the pool. I begin to have problems if the water level gets below about 3/4 way up the skimmer. The weir in the skimmer can interfere with water flowing into the skimmer when the water level gets just a bit too low and the pump starts pulling in small amounts of air through the skimmer. Eventually the pump draws in enough air and begins to cavitate, the flow is drastically reduced and can even stop completely.

 

[marsui]

I am not sure what you have going on, I when the flow rate goes down, and the pressure does not rise, is there then air in the pump stainer basket? If not I would begin to suspect you may have a bad pressure gauge where the needle sticks once it gets to a certain point and you are actually have a pressure rise.

Literally, the gauge stopped working today. Maybe it was on the way out. Ordering one now. No air in the pump strainer basket, I've not seen a cyclone being generated, the water is about half way up the skimmer.

Is this an in ground or above ground pool?

Suction side leaks are unlikely with an above ground as the water will have head pressure all the way to the pump. What can happen is simply not having enough water in the pool. I begin to have problems if the water level gets below about 3/4 way up the skimmer. The weir in the skimmer can interfere with water flowing into the skimmer when the water level gets just a bit too low and the pump starts pulling in small amounts of air through the skimmer. Eventually the pump draws in enough air and begins to cavitate, the flow is drastically reduced and can even stop completely.

Above Ground Pool. Water 1/2 way up skimmer, but with the basket there I never see a cyclone being created.



I did the shaving cream test, no dimples at all. I ordered a new gasket for the leaf basket on the pump, and I think I might order the gaskets for the top of the EC40 next since it does leak a tiny amount of water. Could air be entering from the top of the DE filter?

Since the EC40 is so old, what should I be looking for to ensure the fingers are working properly? Just rips in the mesh? I never see any DE going into the pool..

Also, if after adding new DE the pressure is high, what does that mean? I don't trust the gauge now that its not working anymore (as I stated before it was probably already faulty) but the pressure would start at like 16-17psi even after backwashing and adding new DE.