How to drain my pool?

Jun 1, 2013
26
Georgetown, TX
Newbie here trying to maintain my own pool. This is a new pool approx 15 months old. I've never had to drain any water before this, but a recent water test indicates a high CYA level (90) and the pool calculator ways to drain part of the water and replace with fresh. I thought this process would be simple but of course nothing is simple the first time you do it.
Let me briefly go through the steps that I did and then the results. I'm sure someone will be able to tell me where I went wrong :)

  • I unrolled the drain hose onto my lawn.
  • I then switched the setting of the main valve (i.e. not sure of the correct name but it's the thing I use to do backwashes, etc. which is plumbed between the pump and the filter) to the "waste" setting.
  • I then started the pump on speed 2, then switched to 3
  • Water started draining out of the hose for perhaps 10-15 minutes.
  • The water level of the pool dropped a couple inches or so.
  • Then the water just stopped draining. I noticed the basket of the pump was empty and the pump showed a "priming dry" alarm.
  • I then looked in the pump manual and it said to fill the basket with water and re-try, so I got out my garden hose and did that
  • Started the pump again and it started draining more water out of the hose for a minute or two, then stopped again...eventually another priming dry alarm
  • At this point, I figured that I should have closed a couple of valves before trying to drain, etc. so I closed the skimmer valves and tried the pump again, no dice. (these are the same valves I close when I'm doing a backwash).
  • Re-opened the valves, filled the pump basket with water again and started the pump. Water started to drain again but only for a minute or two then stopped again.
  • I stopped at this point, filled the pump basket with water again and put the system back on "Auto" and decided not to fool with it any more for now.

So, my question is... what exactly should I do to drain water out of the pool?

Let me post a few pictures of my equipment.

1) Main valve:
20140505_182532.jpg


2) Pump:
20140505_182559.jpg


3) Filter:
20140505_182541.jpg


4) Skimmer valves, etc.:
20140505_182612.jpg

Note: when I do a backwash, I close the two valves on the left. I've never touched the two on the right. Unfortunately, the pool builder didn't label them so I'm clueless as to what they do.

Correction: I close the two valves on the left only while I'm cleaning out the filter basket on the pump. This is to prevent backflow into the pool and possible priming dry condition when I start the pump back up. After cleaning the filter basket, I re-open the valves and then do the backwash/rinse cycles.

Also, there are two main drains. One is located in the deepest part of the pool, and the other is in the spa.

For reference, here are a few pics of the pool itself that were taken by a photographer hired by the pool builder.

Thanks in advance for any help,
Phil
 
Last edited:
Welcome to TFP!

First, I am not sure why you would need to close suction valves to backwash. It should not affect anything.

If you can isolate the floor drain, then you should be able to pump it out with that powerful pump. Sounds like air is getting into the system somehow. Easiest is to just rent/buy a submersible pump.
 
If you have main floor drains in the deep end, do you have a waste setting on your pump?

We "accidentally" drained ours without the pump being on but the filter set to waste overnight. I presume this depends on levels of drain pipes in relation to floor drains. Our filter and pump are downhill from the pool.
 
I have the exact same pentair intelliflo system and went through the exact same process last week attempting to to a partial drain to lower CYA. Even though I was closing the skimmer valve, whenever the water dropped below the level of the skimmers the pump would stop and say priming dry.

I called my PB and they told me even though I turned the skimmer valve as far as it could go that was only closing off one skimmer. To close both skimmers you loosen the black wing nut on the front of the valve handle. Pull the entire valve handle out, or toward you. When you have pulled it toward you, you will be able to turn the handle the rest of the way, closing off both skimmers. After doing this it drained perfectly through the waste. We drained half the pool in two hours.

It you are not sure which handle is the skimmer valve, I suggest closing the one you think is correct, turn the pump on in the filter position and see if the water is not moving in the skimmer baskets. Then label with a sharpie.

EDIT: Here is a photo of our skimmer valve with one skimmer closed. Handle is to the left. When the handle is pointing straight up both skimmers are open. When the handle is aimed straight down both are closed, but you must loosen the nut and pull the valve outward to put it in this position.

View attachment 28953


Hope this helps.
 
Last edited:
Welcome to TFP!

First, I am not sure why you would need to close suction valves to backwash. It should not affect anything.

If you can isolate the floor drain, then you should be able to pump it out with that powerful pump. Sounds like air is getting into the system somehow. Easiest is to just rent/buy a submersible pump.
When we first opened up the pool, the pool builder sent over someone that gave us instructions on the basics. IIRC, he recommended we just close those 2 valves so that when the pump was running for the backwash and rinse cycles, that water didn't drain back into the pool or something like that. I never really questioned it at the time and just follow those instructions each time I do a backwash.

- - - Updated - - -

If you have main floor drains in the deep end, do you have a waste setting on your pump?

We "accidentally" drained ours without the pump being on but the filter set to waste overnight. I presume this depends on levels of drain pipes in relation to floor drains. Our filter and pump are downhill from the pool.
Yes I have a waste setting on the main valve thing that sits between my pump and the filter (see pic in my original post). That's what I set it on when I ran the pump to try to drain the pool. My pool is on a fairly level plane with my pool equipment so I don't think I can just use gravity to drain it :)
 
I have the exact same pentair intelliflo system and went through the exact same process last week attempting to to a partial drain to lower CYA. Even though I was closing the skimmer valve, whenever the water dropped below the level of the skimmers the pump would stop and say priming dry.
Now that I think more about what happened earlier tonight, I think this is also what was happening to me. Once the water level dipped down below the skimmer opening, that's probably when the water stopped draining. Makes sense now :)

I called my PB and they told me even though I turned the skimmer valve as far as it could go that was only closing off one skimmer. To close both skimmers you loosen the black wing nut on the front of the valve handle. Pull the entire valve handle out, or toward you. When you have pulled it toward you, you will be able to turn the handle the rest of the way, closing off both skimmers. After doing this it drained perfectly through the waste. We drained half the pool in two hours.

It you are not sure which handle is the skimmer valve, I suggest closing the one you think is correct, turn the pump on in the filter position and see if the water is not moving in the skimmer baskets. Then label with a sharpie.

EDIT: Here is a photo of our skimmer valve with one skimmer closed. Handle is to the left. When the handle is pointing straight up both skimmers are open. When the handle is aimed straight down both are closed, but you must loosen the nut and pull the valve outward to put it in this position.

View attachment 28953


Hope this helps.
Thanks for taking the time to take pics and everything. I think this should help. One thing I noticed in your picture, though, is that you have 2 skimmers being controlled by the one valve and I think the two valves on the left in my picture are each controlling one skimmer. But tomorrow night, I'll do some experimenting like you mentioned above and see if I can figure out what all the valve handles are for. Failing that, I'll grab the pool builder by the scruff of the neck and drag him over here to label everything :)
 
Maybe the valve handles for each of your skimmers are only closing them partially. See if you can loosen the wing nuts on both of them and close them fully. If that fails it is probably time to call the builder. :)
After talking with my pool builder, I now know what all the valves are for :)
In the picture below, the 4 valves closest to the ground are (from left to right): the main pool drain, the skimmers (both are tied to the same valve), the spa drain and finally the valve which controls the fountain/bubbler in the shallow ledge area of the pool.

As I speculated above, my problem was that I was not closing the correct valve and the skimmers were draining and then the pump ran out of water to push. Tonight I completed the drain and refill by simply closing the skimmer valve, running my pump with the main selector knob thingy turned to "waste" and everything worked just great. On the refill, I supplemented the auto-filler with my garden hose, plus we got a good heavy rain this evening here in Central Texas so that helped as well. Next, I'll re-test the water and see where I'm at.

20140505_182612.jpg
 
When we first opened up the pool, the pool builder sent over someone that gave us instructions on the basics. IIRC, he recommended we just close those 2 valves so that when the pump was running for the backwash and rinse cycles, that water didn't drain back into the pool or something like that. I never really questioned it at the time and just follow those instructions each time I do a backwash.
Ok, I think this mystery is solved. I close the main drain and skimmer valves when I open up the pump basket to clean it out, not when I do the backwash/rinse cycles. This prevents the water from draining back into the pool when I open up the pump basket lid. Normally, I'll close those values then clean out the pump basket, then open the valves again and then do my backwash/rinse cycles. I forgot that small detail before when I was describing what I was doing. Sorry about that.
 
Ok, I think this mystery is solved. I close the main drain and skimmer valves when I open up the pump basket to clean it out, not when I do the backwash/rinse cycles. This prevents the water from draining back into the pool when I open up the pump basket lid. Normally, I'll close those values then clean out the pump basket, then open the valves again and then do my backwash/rinse cycles. I forgot that small detail before when I was describing what I was doing. Sorry about that.

Well that taught me something. I have not been closing the valves to open the pump basket and the water would always drain out, making it take longer to prime afterward. I will try that next time.
 

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