Hayward Vari-Flow valve SP710X making cavitation noise w pump on.

Loud pumps are generally associated with bearing that are going out. If you don't think that could be the issue, debris caught in the impeller could be a possibility. Another would be what is called "Cavitation".

That's where the pump is trying to pull more water through it that the pipe diameter will allow for. This results from too small of a pipe diameter on the suction side line, too long of a run, or too many 90 degree elbows. Unfortunately it is not that uncommon.

To check for cavitation you need to restrict flow back to the pool by valving down (constricting flow) if possible. A good pool tech will be able to tell just by listening. When you restrict flow you should notice a distinct quieting of the pump. Hope this helps.

Is it a vari-flow valve?
If so with the pump off set the valve to "filter" then you can remove the screws on the top of the valve and remove the assembly. The gasket that usually goes bad is the "spider gasket", it looks like a pie-chart. Check this gasket for any tears or bends in the rubber, if you see any replace it. Turning the valve with the pump running will cause these gaskets to go out

I HAVE TO ADD MY TWO CENTS! THANK YOU TO THIS WEBPAGE- I had air and gurgling coming from my Hayward Variflo - I sealed all the leaks, and had crystal clear sight glass on my pump, but it still gurgled- I never in a million years suspected too much OUT flow- and it is the easiest thing to test- just cover one of the outputs to restrict the flow back to the pool, and listen- my noise died right down.
THANKS GROUP

It is still the same valve only the part number adds a zero...it is SP0714T. We sell it for $97.99 with free shipping to the continental US. We currently have several in stock.

John

The sightglass is designed for backwash only, it allows you to see the degree of clarity in the effluent water. There should not be flow through the sightglass when the filter is in normal operation. Sometimes the pump will be alot louder when you backwash because there is alot less back pressure and it sometimes causes pump cavitation. The pump should quiet down when in normal filter mode. If not, there may be problems with the bearings and/or cavitation.

The model number you give is for the multi port valve. Did you need the valve manual or the filter manual? Go to haywardnet.com for their full line and manuals. Here is the link for the SP0714 valve at their site. It is in PDF format...

Most hayward sand filters use a GMX600F or GMX600F-H o-ring.
If it is an older tank it might use the GMX400F which is smaller, and rare to come across. Most 400 Valves are not marked vari-flo.

Hope it helps.

It will not be glued, it is just stuck in there good. You will need to scrape, pull, twist or otherwise convince it to come out as best you can and then clean the area well before installing the new one.

You can replace the spring inside if it is too loose, however you are unlikely to see damage on laterals. It only take a couple thousanths of an inch wear for them to allow sand and/or dirt past.