Blowing out pipes that are 20 feet below surface of the pool

[neutral0]

My pool is situated on a hill. I have two returns and one skimmer. No main drain. The pool is painted concrete and was probably built in the 1940s or 1950s. My pump is located about 10 feet below the waterline of the pool, down the hill. My filter is in the basement of a little pool hut and is another 10 feet down (20 feet below the surface water of the pool). This means that all of my lines have a straight vertical run from the pump, down 10 feet into the hut, across the floor of the hut about 10 feet and then back up and out of the hut to my heater. The pressure gauge on my filter registers 10 PSI even when it is off, because of this.

I've had a pool company blow out the lines -- sometimes with a air compressor and sometimes with a Cyclone. Each time they have been able to get the lines to blow and have gotten the anti-freeze to spray all the way through the pipes. When I talked with the guys who closed last year, they did say that it was hard to move the water through my lines.

This year, I set the multiport to recirculate, blew the water with my shop vac from the farthest return to the pipes in the basement (hoping to work with gravity), opened the cap on the pipe and let the water out. Then, I blew the water from the skimmer to the floor and let the water out an opening in that line at floor level. Then, from the skimmer, I blew out each outlet and the heater with only one of these open at a time, This seemed to get rid of the water. However, there was never any really strong "spray," maybe because a lot of the pressure was already gone with the water I let out at the pool hut basement level???

How do I know if I got all the water out of the lines?

I put antifreeze into the skimmer and blew it down toward the pump and the pool hut, hoping that it would continue to go past the pump, through the basement, up through the heater and into the returns. However, it seems like the stuff gets to the bottom of the hut and sits there. I get air from the returns, but no antifreeze. I borrowed a Makita Mac 2300 and used that to blow from the pump at about 10-20 psi, with the same results: tons of air from the last outlet (all others were plugged), but no antifreeze. We added more antifreeze, with the same results. It sounds sort of like the antifreeze starts to go up the 10 feet of vertical pipe and then just stops. I went a little higher in pressure for a few minutes, but stopped, because I was afraid I'd cause damage to the pipes.

What am I doing wrong??? Should I have a valve closed that isn't? Do I not have enough pressure? Not enough antifreeze? Something else? I have seen this work (but, to be fair, they did it and got a spray without having drained the lines first, so maybe there was more pressure in the lines from the water?)! Am I ok?

We did manage to pour two gallons of antifreeze into the outlets, blow with the vacuum back towards the pool hut and cap the returns. But for all I know, most of it is sitting on the floor of the pool hut.

We also put a little antifreeze into the place where the plug comes off of the heater. Not much, because it came flowing back at us. Will this work? If not, how do i add antifreeze to the heater without having wash back down into the pool hut? (As far as I know there is no check valve. Should there be?)

The following should be a drawing of my pool set up. Arrows show the flow of the water, dotted line shows where the pipes are moving vertically into the basement of the pool hut.

I'd appreciate any advice you have.

 

[Catanzaro]

Can you please "Go Advanced" remove picture, then rotate picture, save and upload again to make it easier to view.

I am having a little difficulty following this thread, maybe because it is early morning (LOL). You also 1 skimmer and 2 returns. It is a concrete pool. Did you have trouble blowing out the lines? Is this the issue? No Main Drain could be a good thing in this case. If you have a concrete pool, how low are the return jets? Maybe draining everything below the returns, pushing as much water as possible out of the system and then pouring RV Anti-Freeze is your best bet. Most pumps and the equipment pad sit above, not below the pools water line.

Your pressure gauge should be at "zero" when the pump is not running (unless I am missing something), so chances are that the gauge is defective.

If I am understanding properly, you worked backwards. You blew out the lines from the pool to the basement at the equipment pad to have gravity work to your advantage. Is this correct? What did you hook up to the returns to blow out the lines? Once you removed this, did you quickly cap off the returns or was the water level below the returns?

You should be able to remove the water (if you can isolate each return(s) and skimmer separately) even at these elevations. Although, the water should be drained below the returns at this point. You can still work from the pool to the basement, allowing gravity to be on your side.

Please advise!

 

[neutral0]

I've had this discussion about my pressure before (see ewkearns response on this page Is there something wrong with my skimmer? - Page 2). I don't understand why this is, but he is right. I have a brand new fluid filled gauge that matches the 10 psi I had on all the other gauges. So this has been tested and retested. Odd, I know.

I can't seem to get the picture to reload, so I'll try later. I have drained the pool down about 6 inches below the returns. Then, I drained as much water as possible to the floor of the pool hut, then used the shop vac to blow out the remaining water. My concern is that I never saw the kind of spray that I saw when the pool guys are here. Is that a problem? Or is it normal given that I drained my lines first and only have a shop vac?

Also, we couldn't get the antifreeze to go all the way through the lines like the pool guys did, so I wasn't sure that the lines were clear. There is gurgling in the basement of the pool hut, but at this point, it must have a lot of antifreeze in it, because that is the low point on my pipes and they had been drained. If all of the antifreeze has gone down the hill, then is there nothing in my skimmer line? Should I shut off the valve at the pump to keep the antifreeze in the line from the skimmer or doesn't it matter if most of the water is down the hill too? Do I pour antifreeze over the plugs in the skimmer and then put in the half full jug of antifreeze? (Clearly, I don't really know what I'm protecting here!)

And, finally, what do I do with the heater. Since the antifreeze isn't blowing up the 10 feet of vertical line to the heater, I have no idea what these lines hold. We did open up the plug and felt lots of air coming through. Then, we added in a little bit of antifreeze to the plug area. Is that enough? Or do i need to do something else?

 

[samt]

The pool guys most likely used a blower that had more volume than your shop vac. Since your trying to blow out water with a low volume piece of equipment compared to what the pool guys used, I think what's happening is you blowing air over the top of the water that's still in the pipe. Like you said your working against gravity and the heavy water is staying on the bottom of the pipe, while the air is being pushed out on top of the water in the pipes. That's why,especially in your case you need a high volume blower. The pool guys already said they had a hard time.

 

[Pool Tool]

For the pressure gauge - water weighs 0.433 lbs per vertical foot. That is why ewkearns mentioned a 23' difference in top of water height and gauge, i.e. 23' x .433 #/ft = 10 psi. This makes sense with the OP's equipment setup.

 

[mas985]

Any pipe that is buried below ground 4' or deeper has no real chance of freezing so I wouldn't worry too much about those sections. For shallow pipe, anti-freeze should take care of that. Also, having just a little bit of air in the lines can prevent them from bursting if frozen. A pipe does not need to be water free to protect it from freeze damage.

 

[samt]

Based on the op's statement that his pump is 10' below the waterline of the pool and he still has water in the pipes, I would bet that the pipes nearest the pump are 100% full of water. The question is. Are those pipes below frost line?

 

[mas985]

If the hut sits above ground but is still below the water line, why not drain the pool below the skimmers and returns and just drain from the pump location until the lines are empty? Also, there are periscope lines that can be attached to the returns so you can drain the water out of the lines without lowering the pool level. The pipes to the skimmers and returns just need to be above water level to allow the air in so the water can just flow out of the pipes.

method used on water returns for closing - makes me nervous - need help!!

 

[Pool Tool]

mas - exactly what i was thinking but was too lazy to type it out.

Leave the plugs out near the pump, filter, etc. and then even if the periscopes leak there will not be enough built up water to cause an issue.

 

[Catanzaro]

The pool guys most likely used a blower that had more volume than your shop vac. Since your trying to blow out water with a low volume piece of equipment compared to what the pool guys used, I think what's happening is you blowing air over the top of the water that's still in the pipe. Like you said your working against gravity and the heavy water is staying on the bottom of the pipe, while the air is being pushed out on top of the water in the pipes. That's why,especially in your case you need a high volume blower. The pool guys already said they had a hard time.

Samt is correct. Not enough volume is the issue here. It may be best to invest in a volume blower, like the Cyclone. Understand that it is getting late in the season, but I still believe you have time before any real frost.

Any pipe that is buried below ground 4' or deeper has no real chance of freezing so I wouldn't worry too much about those sections. For shallow pipe, anti-freeze should take care of that. Also, having just a little bit of air in the lines can prevent them from bursting if frozen. A pipe does not need to be water free to protect it from freeze damage.

Mas985 hit is on the nose. Your skimmers and return jets (any water below 4' will not have any issues) and you pushed most of the water out. If you leave your piping open for these areas in the basement, because of gravity, water may still move toward the basement. Water only needs the slightest pitch to travel.

One last thought and this is hard to picture. If somehow you could plug your main drain so it is somehow sealed for the winter, maybe you can use a shop vacuum to remove water out of the system. I have not seen any covers that go over the MD to completely seal them off (based on gravity). So air must be removed from the basement to create an "air lock" at the valve. I do not see any other way. Maybe some of the other members here can shed some light with the MD.

If you pushed air through the return jets, water was removed from the heater as well. Water goes from the filter to the heater and then to the return piping. Coming from the pool, you have return piping, heater, and then filter. Therefore, you could not have avoided having air being pushed out of the heater. There should be a drain plug on the heater as well.

 

[neutral0]

Thanks everyone for your advice. I'll reserve the periscope method for next year, as I've already drained the pool down past the returns. This was the method used by the previous owners and I feel comfortable sticking with this. I have no main drain, so that is not a concern. And I'm glad to have confirmation of the physics of my filter pressure! That has been a mystery for a while.

After I drained the pool into the basement of the pool hut, I blew the lines from the skimmer and from the returns. So I believe that most of the water in the lines settled at the low points, which would be (from skimmer) at the entrance to the pump, which is underground; and (from the returns) which is also underground and then goes vertically to the basement of the pool hut. What I don't know is how far under ground the pipes go, as I have no documentation about the construction of the pool. Then, I put in about two gallons of anti freeze in at the skimmer location and at the returns. I think it makes sense that the antifreeze will wind up where ever the water wound up and that this (along with the air that exists in at least part of the pipes) will protect my lines in these areas. Is this correct? So then, I would be good from returns to bottom of pool hut and from the skimmer to just below the entrance to the pump. Please correct me if I'm wrong here.

I will drain and remove the pump and store it in the garage, as the pool hut is not heated, just under the ground (so the pipes are blow the surface of the ground, but not insulated with any sort of dirt). I will close the valves to both of the lines to the pump and plug the returns. Since there is antifreeze in there it should be ok, right? I could add a little extra to these two areas just to make sure.

I'll check the basement lines to make sure they also have antifreeze in them. Or is it better to leave these open?

I'm still not clear on what do I do with the heater, which I can't remove. I did open the drain when I was blowing from the returns and first water and then air came out. And we put a tiny amount of antifreeze in the place where the plug was. Is this good? Or should I be opening the plug for the winter?

Also, skimmer: do I fill the bottom of the skimmer with antifreeze and then put in the jug to help with expansion/contraction?

I'm looking for a Cyclone, but now that I have all the antifreeze in the lines, I'm not sure I want to blow it all out...

Thanks again for your help.

 

[mas985]

Also, skimmer: do I fill the bottom of the skimmer with antifreeze and then put in the jug to help with expansion/contraction?

That should be free of water now, no?

If you drain the water below the skimmers and returns and open the pipes at the pump level, then nearly all of the water should have drained out. Any local low spots were some water should have gotten trapped should not be an issue. There should be plenty of room for the water to expand should it freeze. You really shouldn't need any anti-freeze unless I am missing something.

 

[Catanzaro]

I'm still not clear on what do I do with the heater, which I can't remove. I did open the drain when I was blowing from the returns and first water and then air came out. And we put a tiny amount of antifreeze in the place where the plug was. Is this good? Or should I be opening the plug for the winter?

I had written this before. Unless I missed something with the configuration of your heater. Please post some pictures if you can.

If you pushed air through the return jets, water was removed from the heater as well. Water goes from the filter to the heater and then to the return piping. Coming from the pool, you have return piping, heater, and then filter. Therefore, you could not have avoided having air being pushed out of the heater. There should be a drain plug on the heater as well.

 

[samt]

I always put a little antifreeze in each skimmer box along with the jugs to protect the plastic boxes from cracking if they should get some water and freeze.

Even though I lower my water, we get a lot of rain before freeze up. I don't feel comfortable not protecting those boxes in case they get water in them. Cheap insurance.

 

[neutral0]

There should be a drain plug on the heater as well.

I don't understand what you mean by this. There is a plug in the heater, right now holding in a little antifreeze. Should the plug stay in for the winter or come out?

In regard to the skimmer, since I have the antifreeze, I guess it makes sense to use it as insurance.