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Pressure washer to clean out pool lines ??

Pressure washer to clean out pool lines ??


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Old 04-08-21, 09:07 AM
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Pressure washer to clean out pool lines ??

A week or so I was focused on replacing the pump's impeller to improve system's pressure. (I intend to change the sand as well). My main interest today is trying to improve the suction on the vacuum line. The pressure for the surface drains is around 16. The pressure for the vacuum line is around 12. The pressure for the main drain is 20+.

I have tried shoving wire etc up the vacuum intake but it doesn't get very far (either due to a blockage or perhaps a sharp bend in the pvc line.

What do you think of my putting on a wetsuit and trying to shove a 3500 psi pressure washer wand into the vacuum opening ? (There do not seem to be any youtube videos using this approach).
 
  #2  
Old 04-08-21, 09:18 AM
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I wouldn't connect a pressure washer to any of my pool lines.

What are the "pressure" numbers you are posting ?
The reading on the pressure gauge on the tank ?

trying to improve the suction on the vacuum line.
Why ?
 
  #3  
Old 04-08-21, 09:29 AM
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[How do I reply directly to your post ?]

Why wouldn't you use a pressure washer to clear our your pool lines ? Our lines all run underground (or under concrete) .

Yes the numbers I am posting are coming off the gauge.

The vacuum suction used to be really strong. Now it has decreased to the point where 'sediment' (and from time to time we get algae, volcanic ash, stuff from nearby forest fires and just dust/dirt thrown around by the winds) gets resuspended (regardless of how slowly I move the vacuum head). Not enough dirt is being vacuumed up.

 
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Old 04-08-21, 10:39 AM
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"Why wouldn't you use a pressure washer to clear our your pool lines ?"
The first issue is how will you seal the pressure washer wand to your pool's piping? If you don't get a good seal the low volume of water from the gun will leak back out around the opening where you're squirting it in. Secondly, since you are getting some flow through the line the pressure washer will never develop pressure in the line. Even a tiny opening in the pipe will allow the 2 or 3 gpm of the pump to flow through without developing any significant pressure. Thirdly, the low flow volume of a couple gpm isn't enough to blow or wash out a clog. And fourthly (is that really a word?) the powerful, focused blast of a pressure washer is much more quickly dissipated under water. That 12" of good cleaning spray you get in air is down to a inch or two under water.

What I would try is a jetter attachment for your pressure washer. They are inexpensive and can be ordered online. It has several jets pointing back at the hose to help propel it forward and one jet forward to help break up a clog. Still, any 90 fittings in the line will pose a problem.

As a second thing to try I would get a gas powered water pump, maybe 2" and some fire hose. Draw water from the pool and pump it into the suction line. This pump will develop moderate pressure topping out at less than 100 psi so there is reduced chance of rupturing you piping and the high volume of high velocity water will be able to carry heavy sediment out of the line like a raging river.
 
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Old 04-08-21, 11:34 AM
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I've had a similar situation a few years back. The pool vac ate a small thin thermometer and it got stuck in the line. Then, I asked our local iron worker to make a 'hook' of sorts. He made a 30-40 ft long strand of heavy gauge wire/iron with a 90 degree bend at the end. I jumped in the pool, inserted the 'tool' into the side of the pool and after two minutes of wiggling the thermometer popped out. I got really lucky. About 3 feet off the pool wall (under the lawn) the plumbing takes a sharp 90 degree bend. At some point I did dig up the area and I may have softened that bend (I'm getting old). Looks like I will have to dig that area up again.

I have since donated the wire extractor back to the iron worker - but I may need to see if he still has it laying around.

With that thermometer problem, I did have a guy come by with an external pool pump. We were trying to suck out the line. It didn't work.

I saw the jetter attachment on a youtube video earlier this morning but I'm sure my problem is after the first bend in the plumbing. (It wouldn't travel far).

Since earlier this morning I tried to suck out the vacuum line with our tiny wet-dry vac. We have never used the wet feature of that vac before and it is just not strong enough. It might be good enough to vacuum up a puddle but it did nothing when I shoved it into the side of the pool.

Edit : The other thing I am a little worried about is that my real problem at the moment is at the ball valve back in the pool room. That valve sits well under the level of the pool. And I would have to drain about a foot of water from the pool for the water level to be under the poolside inlet. If I go that route, then I will have to post photos and ask new questions because I'm not sure how I would remove the 1 1/2" valve from the existing pool-room plumbing.

 
  #6  
Old 04-08-21, 12:12 PM
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I found that the easiest way to clean out the suction line on my old inground pool is to blow out the lines by adding compressed air from a 5hp 60 gallon compressor at the skimmer to blow gunk out the bottom drain.

I created an adapter by unscrewing the end valve from a tire chuck, leaving the 6" tube. Then got an old toilet plunger, removed the handle, turned it upside down, slowly push the air tube through the plunger to create a rubber stopper that fits snugly into the suction inlet pipe.

Pull the trigger and wait. After about 30 seconds the pool looks like Godzilla is about the rise up from under the water due to all the roiling bubbles.
 
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Old 04-08-21, 01:36 PM
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So - how much different is your solution to my using my pressure washer ?

I have a screw on cap which fits the vacuum inlet port. I could drill a hole into it, insert the wand, and 'pull the trigger'...

Someone on this forum once told me that both air and water are fluids. Actually, if I understood, water should push through air.

At this point I am going to start digging in the morning.
 
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Old 04-08-21, 02:47 PM
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The difference is the volume. A pressure washer puts out a small amount of water at very high pressure. I assume the air compressor method is similar to blowing out water lines before winter where you dump air into the line as fast as possible to blow the water out.
 
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Old 04-08-21, 03:09 PM
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Sorry for beating this to death - but over time ( several minutes) wouldn't the small amount of water increase the pressure in the pipe ? If it were a sealed system (if I managed to close off the hole through which I inserted the pressure washer wand) wouldn't the pressure reach a level similar to an air compressor ?

Physics was always one of my least favorite subjects - although believe it or not I did manage to pick up a handful of US patents (in an unrelated field). So if air and water are both fluids - at some point isn't 'the difference is the volume' obviated' (equaled out) ?
 
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Old 04-08-21, 03:43 PM
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If you have "some" flow from the pool to your filter..... using high pressure anything from the pool in is likely not to add any improvement. If you think something is caught in the vacuum/suction line then you need to blow from the filter out to the pool to dislodge it.

I had a Fisher Price round wooden man toy stuck in my vacuum line. One of the little ones had picked up the strainer basket and dropped it in. I ended up using an air compressor and tank of water to blow it out from the filter end. It took several shots before it came loose.
 
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Old 04-08-21, 04:22 PM
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Originally Posted by lhpdiver2
So - how much different is your solution to my using my pressure washer ?
AIR is compressible, and stores a scary amount of pressure/power.
WATER is incompressible, and doesn't store pressure/power

It's similar to why you never tow a car with a stretchy rope or cable, they store energy and if they break they can injure or kill you. Instead, you tow a car with a chain, or a minimally-flexible towing strap.

That is why air compressor tanks are generally pressure tested by filling them with water- if they fail, they spring a leak. If you fill them with air, they can go BANG.
Catastrophic failure of compressed air is BAD.

Mythbusters S15 E14 "MythBusters vs. Jaws"
https://youtu.be/r21-kG7sljg

 
  #12  
Old 04-09-21, 05:24 AM
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"...over time ( several minutes) wouldn't the small amount of water increase the pressure in the pipe?"
No, as long as you are getting some flow through the pipe anything your pressure washer puts in will just leak out. Probably won't raise the pressure more than a few psi. Look at the tiny hole in the tip of your pressure washer's gun. It doesn't put out much water. All it takes is a hole a bit bigger than that really tiny hole to let the water escape the pipe just as fast as your washer can put it in. That's why you need VOLUME. You need to put so much into the pipe so fast that it can't leak out fast enough.
 
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  #13  
Old 04-10-21, 12:39 PM
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To follow up :
You guys don't think something like this is worth trying ?

https://www.amazon.com/gp/product/B0...language=en_US

The guy who published this video recommends it (and it looks like it works for him).

https://www.youtube.com/watch?v=EKeqgNBScUs

Edit : I do hate to have to buy yet anther 50 ft pressure hose as I already have one. Maybe tomorrow - if it is as sunny as today - I'll hop in the pool and just try shoving the pressure hose into the vacuum tube and see how that goes. Yesterday I did hook up with our iron worker friend and he will create me a new 5 meter strand of wire with a hook at the end as well. I think this time I will find a place to store it rather than returning it.

 

Last edited by lhpdiver2; 04-10-21 at 01:30 PM.
  #14  
Old 04-11-21, 02:21 PM
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Crickets ?? I am not dissing any suggestions made here. I was just putting forward an alternative.

 
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Old 04-11-21, 09:21 PM
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This is a dedicated vacuum line going from the side wall of the pool directly to a valve at the filter ?

I don't have a dedicated vacuum line. I plug the vacuum inside the bottom of the skimmer. That connecting pipe blocks off the line going to the bottom drain. Then I shut the valve off to the other skimmer/bottom drain.

Jetting may work. It's usually good at breaking up grease clogs and the like. I'm not sure what you would have in the vacuum pipe that would clog it. If it's a straight piece of pipe with no fittings.... it shouldn't really clog. If there are fittings.... like 90's underground.... you won't be able to jet past it.
 
 

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