AutoFill Flow Rate

[ShallowWater]

Mine seems to trickle.

Is this normal?

 

[JoyfulNoise]

Yes. Mine trickles a little most days. They are not designed to act like hose ends but rather use float valves to keep a pool level constant. The flow rates are closer gallons per hour rather than gallons per minute.

Evaporation depends on the difference between the water temp, the air temp and the dew point. Even water that is colder than the air temperature can evaporate if the dew point temperature is very low (low relative humidity). In that case, an auto fill will trickle a bit to make up for evaporation losses.

 

[ShallowWater]

Okay. Cool. Even if I push down the little float, it trickles. I'm fine with that as long as the water stays on the tile line.

 

[JoyfulNoise]

Okay. Cool. Even if I push down the little float, it trickles. I'm fine with that as long as the water stays on the tile line.

Ok. If you push down the float and you don’t get a good gush of water then there’s potentially an issue. I misunderstood what you were asking.

Please show us pictures of the auto fill valve and where it hooks to your household water supply.

 

[1poolman1]

Mine seems to trickle.

Is this normal?

You should have an anti-siphon (sprinkler) valve feeding the autofill. It should be completely open.

 

[Toxophilite]

The can fills faster than it can gravity drain into pool. So, when the pool level is low in the can, you will see the fill tube go from heavy flow, quickly fill up can, then drain back down and then full flow will happen again. This happens in close cycles, repeatedly. You won't see this much, as the pool level would have to way low to make happen, and with autofill, it should not get very low.

As the pool level rises over time, the float cycles less and less range of motion, only partially opening each time. Briefly, you might catch it filling as fast as it drains and see a constant flow if the pool level is just right.

When the pool level is near topped off per setting of float, it will dribble fill. It can do that for days, weeks, etc..... just keeping up with evaporation.

 

[Dirk]

You should have an anti-siphon (sprinkler) valve feeding the autofill.

Yes, there should be some sort of backflow prevention upstream of a pool's auto-fill valve, but...

Typical anti-siphon valves designed for use with sprinklers are not appropriate for use with an auto-fill valve. Sprinkler valves are not rated to have a second valve down stream of them, because that would apply constant full-pressure to the sprinkler valve's anti-siphon mechanism. Sprinkler valves are intended to only feed sprinkler heads downstream. The proper anti-siphon valve in front of an auto-fill valve should be rated for constant pressure, like this one:

https://www.amazon.com/gp/product/B00KI0WORE/

The other advantage of this particular type of valve is that its backflow prevention capability can be tested periodically to confirm it actually works (typical sprinkler valves don't have any such test ports).

 

[ShallowWater]

I have a reduced pressure principle vacuum breaker by Zurn and the valves are open.

@JoyfulNoise I'll get some pics and post tomorrow. Nevertheless the plumber who did my pool may need to pay me a visit.