Can't run Skimmer and Vac line simultaneously

[Jazzyguy]

Hey Guys/Gals,

I have an 11,300 Gallon pool which has a Vac Line, Skimmer and Main drain. On the pad there are three different pipes coming in each with a shut off valve labelled "Vac", "Skimmer", "Main Drain".

I used the Flow Gauge that came with the Hayward Navigator and in order to set it between the "Min" and "Max" lines on that flow gauge, I have to run the vac line by itself. Otherwise, there is not enough suction. My sand filter was backwashed and shows 10-12psi, the lines are for sure not clogged, pump shows no air bubbles during operation. There just isn't enough juice to run both the skimmer and the Navigator at the same time. Isn't it suppose to work this way? Skimmer and Vac line together? If I try the Navigator doesn't move.

I really, really want to run both at the same time otherwise it defeats the purpose of having a dedicated vac line in the first place if I have to always shut off the skimmer to run it. What do I have to do in order to achieve this?

 

[spidey07]

That's somewhat typical. A dedicated vacuum line typically has a separate booster pump dedicated for that purpose as a single main pump isn't enough to run everything.

When I manually vacuum I close the drain 3/4 way to dedicate suction to the vacuum head which is attached to the skimmer.

 

[Bama Rambler]

Tell us more about your equipment. Pump size, filter size, piping sizes, etc.?

Depending on the size of your pump and what the piping sizes and lengths are, it may be perfectly normal to have to shut off the skimmer and/or main drain (at least partially) in order to get the vacuum to work.

 

[Jazzyguy]

Ok, I just got around to getting more info about my equipment. It's Hayward pump (model C4J2N13B1) which I think is 3/4 HP. The pipes look to be about 2 inch thick. The filter is a Hayward Sand Filter which I have just backwashed.

My other question is then why would the original home/pool owner go to the trouble of putting in/paying for a dedicated vacuum line just to shut off the only skimmer in order to use it. What is the point? What am I missing here?

 

[jblizzle]

Well, the alternative would be to have the vac hooked up in the skimmer ... which would also remove the skimming ability.

It is possible that they used to have a larger pump that could run both, but have since put in a smaller pump to save money on electricity.

Please add your pool details and location as described HERE as it will help us help you.

 

[Jazzyguy]

I updated my sig and added location to my profile. Just gotta get the size of my sand filter and heater specs as I'm not to sure.

So, if I eventually upgraded my pump would that solve my issue and allow me to effectively run the skimmer and pool vac at the same time? What about a booster pump instead?

 

[Bama Rambler]

It all depends on how it's plumbed.
You say the pipes look to be about 2" which means they're 1½" pipes, so upgrading the pump may not help. Like I said, it all depends on how it's plumbed.

Can you post a pic of the pad?

 

[Jazzyguy]

Sure.. This is the pad...







Thanks again

 

[Bama Rambler]

When you're running the vacuum, I'd cut the main drain completely off and cut back on the skimmer until the vacuum works and see how that works out.

 

[Jazzyguy]

When you're running the vacuum, I'd cut the main drain completely off and cut back on the skimmer until the vacuum works and see how that works out.

The problem is there isn't enough suction until the Vac Line is open solely by itself, cutting off the main drain and skimmer completely. To make sure the fault was not with the Hayward Vac unit, the Vac unit was serviced and I used the included Hayward "Flow Gauge" to test the flow and this gauge confirms that the appropriate flow is reached when only the Vac line is open by itself.

From the pics posted above, does it seem that either a larger pump or "booster pump" will give me the suction required to run just the Skimmer and Vac Line simultaneously?

 

[jblizzle]

I don't think a booster pump will do what your are asking.

What size are all those pipes?
How often do you run the heater? You could add a bypass line around it which might reduce the head loss and increase flow rate.
Is there only a single return line?

You could easily go to a larger motor/pump though since you have 3 separate suction lines.

OF course if you get a larger motor, I would get a 2-speed so you can run on low when you do not need the vac on.

 

[Jazzyguy]

Thank you for your help. I will measure the pipes. I have two return jets in the pool. I will definitely look into a larger 2 speed pump eventually.

I just don't understand why the original owner and PB decided on a dedicated vac line in this case. Seems kind of useless to me if you can just plug a vac into the skimmer. Can't run both together, so why put em' both in? :?