Pool Valves: How to Read an Equipment Pad

Hey! It's Erin, and this is the PoolBoss podcast.

It's your first visit to a pool you just took over. You walk around the side of the house, and there's the equipment pad. Pump, filter, heater, and six valve handles. None of them are labeled. The pipe runs in every direction, half of it is painted to match the house, and the last company left you nothing. The customer is standing behind you, and she says, "The heater hasn't worked since spring. The last guy said I need a new one."

So you're looking at six handles, and any one of them could be the reason. Today I'm going to show you how to read that pad in about five minutes, without guessing, and without breaking anything.

Here's why this matters. A valve is the cheapest part on the pad, and it controls the most expensive ones. A handle in the wrong place can make a good heater look dead. It can make a good pump look like it's lost its prime. And it works the other way too. Turn the wrong handle with the pump running, and you can hurt a pump, a filter valve, or yourself.

It costs you in three ways. First, time. A pump that won't catch water after you moved a valve turns a twenty-five minute stop into an hour. Second, the wrong quote. If you tell a customer she needs a heater, and the next company fixes it by turning a handle, you don't get that customer back. And third, the covering tech. The day you're out sick, somebody else is standing on that pad with six handles and no labels, and now it's your company that left nothing behind.

This whole episode is about one thing. The valves on the pad. What each one is doing, how to read it, and when to keep your hands off it.

Here's the plan. First, how a valve actually works, and what the pump does to everything around it. Second, how to read a pad you've never seen, in order, with the reason for each step. Third, that pool with the dead heater, walked through from start to finish. And fourth, where this goes wrong, and the exact words to use with the customer.

Part one. How a valve works.

Start with this. A valve doesn't move water. The pump moves water. All a valve can do is open a path or close one. So every valve on the pad is doing one of three jobs. It's picking where the pump pulls water from. It's picking where the pump sends water. Or it's stopping the flow so you can open something up.

Now, the pump splits the pad in two, and this is the idea that makes everything else make sense. Everything between the pool and the pump is the suction side. Everything after the pump is the pressure side.

On the suction side, the pump is pulling. The pressure inside that pipe is lower than the air outside it. On the pressure side, the pump is pushing. The pressure inside that pipe is higher than the air outside it.

Here's why you care. Take one worn o-ring on a valve stem. Put that valve on the pressure side, and water gets pushed out. You see a drip. You see a white crust on the handle. Put the very same valve, with the very same worn o-ring, on the suction side, and nothing drips. Air gets pulled in instead. The pad is bone dry, and what you see is bubbles in the pump basket.

So a suction side valve never tells you it's leaking while the pump runs. If you restart a pump and the basket is still full of fine bubbles after about thirty seconds, air is getting in somewhere, and the valve stems before the pump are on your list. You find it with a garden hose. Trickle water slowly over the stem while the pump runs. If the bubbles in the basket thin out, you found it.

That's the first thing most people never get told. Drips live after the pump. Bubbles come from before it.

Now the valves themselves. On a home pad you'll meet about five kinds.

The first is a two way valve. Two ports. It opens one line or shuts it. That's all it does.

The second is the three way valve, also called a diverter. Three ports. Water comes in one and goes out one of the other two, or some out of each. Inside is a curved piece called the diverter, with a rubber seal on its face. When you turn the handle, you're swinging that seal around inside the body. Whatever port the seal is sitting in front of is blocked. The other ports are open. So a three way valve only ever closes one thing at a time. Hold on to that, because it's how you'll read one in part two.

You'll find a three way valve in two places. Before the pump, it picks between the skimmer, the main drain, and the spa. After the filter and heater, it picks between the pool returns, the spa, and maybe a water feature.

The third kind is the multiport, the big handle on top of a sand or DE filter. It's a different animal. Inside is a round diverter with a gasket on it, held down against the valve body by a spring. Every position on the dial lines up a different pair of openings. When you press the handle down to turn it, you're pushing that diverter off its seat. So for the second or two the handle is down, nothing inside is sealed.

That's the reason for the rule you already know, to never turn a multiport with the pump on. With the pump running, you've got full pressure going across a gasket that isn't seated. The maker's guide says to always turn the pump off first, to prevent damage and possible injury.

Six positions, quickly, because you want to know where the water goes. Filter sends water down through the media and back to the pool. Backwash sends it backward through the media and out the waste line. Rinse sends it the normal way through the media, but out the waste line, to settle the bed after a backwash. Waste skips the filter and goes out the waste line. Recirculate skips the filter and goes back to the pool. And closed sends it nowhere.

Closed is the one that matters. The guide for that valve says the pump should never be on with the valve closed. It says running the system with no flow will seriously damage the equipment, and that parts of the system can come apart. And there's one more spot on that dial that most techs have never used. Between two of the positions is a mark that says winterize. It parks the diverter so nothing is pressing on the rubber seal. That's where the handle sits for the off season, and it's where you put it before you take the valve top off.

The fourth kind is the check valve. No handle at all. Inside is a flap, usually on a spring, that lets water go one way and shuts when it tries to come back. It does its work when the pump is off. One heater maker's guide says back siphoning is most likely right when the pump stops, because for a moment one side of the pad is still under pressure and the other is still under suction, and the water wants to run backward.

The place you'll see a check valve most is between the heater and a chlorine feeder. Think about what's in a tablet feeder with the pump off. Water that's been sitting on tablets for hours. If that water drifts backward, it's sitting inside the heat exchanger until morning. The check valve is what stops it. And that's the same reason the heater guide says not to put tablets in the skimmer. With the pump off, that strong chlorine sits in the line and ends up in the heater. A check valve can't help you there. The tablets are upstream of everything.

A check valve fails in one way you can't see. A leaf stem or a bit of grit gets under the flap, and it stays open. From the outside it looks perfect.

And the fifth kind is the heater bypass. It's a valve plumbed across the heater so some of the water can go around it. Every heater has a least flow and a most flow. On the one guide I'm working from, the top is one hundred and twenty gallons a minute for every size. That guide says pumps of two horsepower or larger can push more than that, and it recommends a bypass for those pads. The installer sets that valve once. Then, and this is right in the guide, the handle comes off, or gets locked.

One last piece for part one, and it's the one I'd call the big idea of this episode. That heater has a safety switch that keeps the burner from firing unless water is moving. But read the guide closely. It's a pressure switch. It's set at the factory to about three PSI. The guide's own words are that it senses that the pump is running. It doesn't measure flow. It measures pressure.

Most days those are the same thing. Here's when they're not. Close a valve part way downstream of the heater. Flow drops, because you've choked the path. But pressure at the heater goes up, because the pump is pushing against a restriction. So the switch is happy, the burner fires, and there isn't enough water moving to carry the heat away. Now the only thing protecting that heater is the high limit switch, which opens when the water leaving it goes over one hundred and thirty-five degrees.

That's why the guide says the pipe leaving the heater should have no shut-off valve on it at all. And it's why the same guide says, about a pump whose suction is plugged with leaves, "do not rely on the pressure switch." Pressure tells you the pump is on. It doesn't tell you the water is moving.

So, quick recap. A valve only opens or closes a path. Before the pump, a bad valve pulls air in. After the pump, it pushes water out. A three way valve blocks one port at a time. And a heater can have pressure without having flow.

Part two. Reading the pad.

You're standing on that pad with the six handles. Here's the order, and the reason for each step.

Step one. Don't touch anything. Take one photo of the whole pad with every handle exactly where you found it. Here's why. That photo is your way back. If you move three handles and the pump won't catch water, you don't have to remember anything. You put the pad back to the picture.

Step two. Find the pump, and walk the pipe backward from it. Those lines go to the pool. You're on the suction side. Find the valve that picks between the skimmer, the main drain, and the spa. You do this side first because it's the side that can starve the pump, and a starved pump is the fastest way to turn a small mistake into a repair. The seal on the pump shaft is cooled by the water going through the pump. With no water, it runs dry. If a pump hasn't caught water in about ninety seconds, shut it off.

Step three. Go back to the pump and walk forward. On a standard pad it goes pump, then filter, then heater, then back to the pool or spa. If there's a chlorine feeder, it comes after the heater, with a check valve between the two. As you go, put a finger on every valve and say what it does. This one picks pool or spa. This one is the bypass. This one is the waste line. If you can't say what a valve does, you're not done tracing.

Step four. Read every three way valve, and read it the right way. Most people read a diverter by where the handle points. I think that's how pools get set wrong, because the handle is a long piece of plastic that points two directions at once.

Read the word off. On the common Jandy style valve, one end of the handle is marked off. The maker's sheet says that mark shows the exact position of the seal inside. So whatever port is under the word off is the blocked one. The others are open. Remember part one. A three way valve blocks one thing at a time, and the handle is telling you which one.

Point off at a port, and that line is shut. Swing off away, and it opens. Park it half over a port, and that line gets part of the flow. There are stops molded into the cover that catch the handle when a port is fully shut, so you can feel it land.

Two more things are on that cover. The word inlet is molded into it, and it goes over the port where the water comes in. That tells you which port is the common one without tracing pipe. And the knob on top of the handle is a lock. Loosen it to turn the handle. Snug it finger tight when you're done. Here's why that matters. A handle that won't move may be perfectly fine and just locked. And a handle with a loose knob can drift, which is how a valve ends up half way on its own.

Other brands mark their handles differently. If you can't find a mark you trust, don't guess. Pump off. Move the handle. Pump on. Watch where the water goes.

Step five. Before you move any handle, the pump goes off. Every time. You know why now for the multiport. For the others, it's the same idea. For a second or two in the middle of the turn, you may have nothing open. And don't trust the timer. If that pump is on a schedule, it can start with your hand on the valve. Turn it off at the breaker, or put the controller in service mode.

Step six. Look for motors. If a valve has a gray box sitting on top of it with a cord coming out, that's an actuator. It runs on twenty-four volts from the automation panel, and it turns the valve for the customer when they press spa on the remote.

Here's how it works inside. There are two small cams, and each one trips a switch that stops the motor. One cam stops it turning one way. The other stops it turning back. So an actuator only knows two positions, and somebody set those two positions by hand on the day it was installed. The maker's manual warns that wrong cam settings can dead head the water flow. So if a pool and spa switch over and the pump goes quiet, or the spa drains down when it's supposed to be filtering, suspect the two actuators before you suspect the pump.

And don't force that handle. There's a gear train under it. On the common Jandy actuator there's a small toggle switch on the bottom with three positions. To turn the valve by hand with the power off, you move that toggle to the center, which is off. You unscrew the knob on top four full turns. Then you push down on the knob, not on the handle. That drops the shaft out of the gears, and the handle turns freely. To put it back, you pull up on the handle while you turn it until you feel it slide back into the gears. Snug the knob. And put the toggle back where you found it. That last one is the step people forget, and then the customer's remote does nothing.

Step seven. Write it down. One line per handle. What it is, and where it sits for normal running. Put the photo and those lines on that pool's record, where the next tech will see them before they touch the pad. And if the customer is fine with it, mark the pipes with a paint pen. It takes two minutes, and it helps whoever stands there next, including you in a year.

Recap. Photo first. Suction side, then pressure side. Read the word off, not the handle. Pump off at the breaker before any handle moves. And write the normal settings down.

Part three. One pool, start to finish.

Back to the pool from the top of the show. Pool with an attached spa. A gas heater, the four hundred size. A single speed pump. And a customer who's been told she needs a new heater.

You ask her what it does. She says it tries, the service light comes on, and it quits. You look at the display, and it shows an error, the letters PS. On that heater, that message means there isn't enough water flow getting to it.

Here's the first decision. The easy move is to agree with the last company. The heater's eleven years old, it's throwing a fault, and nobody would question you. But that message isn't about the burner. It's about water. And the heater guide gives you a number for this size. It needs forty gallons a minute before it should fire. So your question isn't "is this heater dead?" It's "why isn't it getting forty gallons a minute?"

So you start with the cheap things, because they're the most likely. Water level is fine. The skimmer basket has a few leaves. The pump basket is clean. The filter is a cartridge, and the gauge reads sixteen PSI. You don't have a clean number for this pool yet, so you can't say if sixteen is high. You pull the cartridge anyway and hose it. The gauge comes back at fourteen. That's a filter that was a little dirty, and it's not what's starving a heater.

Now you take the photo, and you trace. Backward from the pump first. One three way valve on the suction side. The word off is sitting over the spa line, so the pump is pulling from the pool. That's correct for normal running.

Then forward. Pump to filter. And between the filter and the heater, there's another three way valve. One port goes into the heater. The other goes around it and tees back in on the far side. That's a bypass. And the word off is sitting half over the heater port.

So right there, about half the path into the heater is blocked, and the other half of the water is taking the easy way around.

Second decision, and this is the one that matters. Is that valve wrong, or did somebody set it there on purpose? Remember what the guide says. A bypass that's been set on purpose has its handle taken off or locked. This one has its handle on. You try the knob, and it's loose. It spins under your finger.

Then you look at the pump. The plate says one and a half horsepower. The guide recommends a bypass for pumps of two horsepower and up. So this pad has a bypass valve on a pump that may not even need one, with a handle that was never removed, and a lock knob that isn't locked. That's not a setting. That's a valve that drifted, or one that somebody bumped while they were cleaning the filter.

So you turn the pump off at the breaker. You swing the word off all the way over the bypass port, until the handle lands on the stop. Now all the water goes through the heater. You snug the knob finger tight. You open the air relief on the filter, turn the pump on, and close it when you get a steady stream of water.

The service light goes out. The heater fires. And now you wait, because the real test of a flow problem isn't whether it lights. It's whether it stays lit. You give it ten minutes while you finish the pool. It's still running when you pack up.

You take a second photo of the pad, with the valve where it belongs. And you write three lines on the record. Bypass valve found half closed toward the heater, knob loose. Set to full flow through the heater, knob snugged. Heater ran ten minutes with no fault.

Then you tell her. "Your heater wasn't getting enough water. A valve next to it had drifted half way closed. I set it back and locked it, and the heater's been running for ten minutes. I'll check that valve again next week. If it faults again, I'll bring in a licensed heater tech, but I don't think you need a new heater."

Think about what that stop was worth. She keeps a heater that was about to be torn out. You spent maybe fifteen extra minutes. And she now has a pool company that found in one visit what the last one was going to charge her a heater for.

Now here's the honest part of that story. If that valve had no handle on it, the whole thing goes differently. You don't touch it. You write down what you found, and you bring in the heater tech, because somebody set that valve to protect the heater from too much flow.

Recap. The fault code said water, so you chased water. Cheap things first. Then the trace. And the handle, the knob, and the pump plate told you whether that valve was a setting or a mistake.

Part four. Where it goes wrong.

Six mistakes cover most of it.

One. Moving a handle with the pump running. You've got the reasons now. An unseated gasket on a multiport. A moment with nothing open on a diverter. And if it's the suction side, a pump with no water.

Two. Reading the handle and not the word off. If you only fix one habit after today, fix that one.

Three. Helping a bypass. You find a valve by the heater with no handle, and it looks half closed, and you want to straighten it out. Leave it. With too much water going around, the heater drops under its least flow and won't fire. With too little going around, it gets more water than it's built for. Neither one is yours to set.

Four. Adding a valve where one doesn't belong. A customer asks for a shut-off after the heater so the spa is easier to work on. The answer is no, and now you know why. A closed valve after the heater gives it pressure with no flow.

Five. Blaming the pump for an actuator. A pool and spa combination that drains the spa overnight, or a pump that strains every time the system switches to spa, is usually a valve problem. It's a check valve stuck open, or two actuators that don't agree with each other. Look there first.

And six. Opening a filter valve under pressure. That multiport is rated to fifty PSI, and the guide calls it a pressure vessel. Pump off. Open the air bleeder. Then take it apart. And when you start back up, open the bleeder first and stand clear until you get a steady stream of water.

Now, when does a valve stop being a setting and become a quote? Four signs.

Water at the handle of a multiport. The guide says that's the o-ring on the shaft, and the fix is a new valve top.

Water running out the waste line while the filter is on filter. That's dirt or sand under the seal, a damaged seal, or a damaged body. Clean the seal area first. If it still leaks, it's a quote.

A cracked port where the pipe threads in. That's a new valve body. And the guide warns you not to overtighten those fittings, which is usually how the crack got there.

And a cracked body on a three way valve. On that common Jandy valve, the body isn't sold as a separate part. A cracked one means a whole new valve.

One more that isn't a quote at all. On older valves with a small grease cap on the body, the seals need grease. For a valve under an actuator, the maker says at least every three months. The newer style has no grease cap and never needs it. So a stiff older valve under an actuator may only be dry.

Know where you stop. Turning a handle is your job. Cutting in a new valve is plumbing. The maker's own sheet says that valve has to be installed and serviced by a contractor who's licensed where the state or city requires one, so check your state's rules before you glue pipe. And anything inside the heater cabinet, gas or electrical, goes to a licensed heater tech. You stop at the valves.

When you talk to the customer, name the valve, say what you saw, and say what happens next. Here's a quote. "The valve on top of your filter is letting water out the waste line while the pool is filtering. That's water you're paying to replace every day. I cleaned the seal and it's still doing it, so it needs a new valve top. I'll send you the quote today with a photo." And here's a hand off. "There's a valve next to your heater that was set by whoever installed it. I think it's been moved, and I'm not going to guess at it. I'd like a licensed heater tech to reset it."

Both of those sound like someone who's read the pad. Because you have.

Alright, let's wrap it up. Here are your takeaways.

One. The pump splits the pad in two. Before the pump, a bad valve pulls air in, and you see bubbles. After the pump, it pushes water out, and you see a drip.

Two. Read the word off. The port under it is the closed one. And the pump is off at the breaker before any handle moves.

Three. A heater fault that talks about water is a valve question before it's a heater question. Pressure doesn't mean flow.

And if you only do one thing this week? Pick the five pads on your route with the most handles. Take one photo of each with the valves where they sit for normal running. Write one line per handle, and put it on that pool's record. The next time a pump won't catch water or a heater won't fire on one of those pools, you'll know in ten seconds whether a handle moved.

That's it for today. Thanks for listening to the PoolBoss podcast. I'm Erin. See you next week.