Pentair SunTouch Tips

Yesterday I installed a Pentair SunTouch with an Intelliflo VS+ pump.

This is a nice simple setup that allows the pump to change speeds depending upon whether it needs more power to send the water up to the solar panels on the roof or more water to satisfy the flow demands of a gas heater or the spa jets. So, for a basic pool & spa system with solar it is nice and simple.

However, there is a bit of a learning curve and some surprises in store for those not used to the SunTouch. The first is: HOW DO I STOP THIS THING?

On most pools, it is easy to turn off the pump to clean the basket. With the old mechanical time clocks, you just have to flip the switch in the timer. With the EasyTouch, IntelliTouch, Jandy Aqualink, and Jandy PDA you just press one button to switch from Auto mode to Service mode and the pump goes off.

Well, the same principle applies with the SunTouch, but it takes quite a few button pushes to get there. To turn the pump off if a schedule has turned it on, you need to switch from Auto to Service.

On the SunTouch:

1.       Press Menu button 14 times until you see “Service Mode 14/14.”
2.       Right arrow into the service menu.
3.       Use up or down arrow to change from Auto to Service.
4.       Press right arrow to select Service mode.
5.       With the pump in Service mode, clean the pump basket or filter as needed.
6.       To restart, repeat steps as needed this time changing from Service to Auto mode.
a.       In addition to Service and Auto, there is also a Time Out mode. It is like the Service mode, but it will automatically switch back to Auto after a 3 hour delay.

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Possible Patent Infringement regarding Variable Speed Pumps

Pentair asks for an injunction that aims to force Hayward to stop selling the EcoStar.

Pentair Pool Products, manufacturer of the IntelliFlo and the IntelliPro lines of variable speed and variable flow pumps, in association with Danfoss Drives--the makers of their variable frequency drives, filed a motion on August 31, 2011 requesting an injunction that would stop Hayward, manufacturer of the EcoStar from selling their EcoStar pump.

Pentair & Danfoss (collectively referred to as Pentair in the brief) maintains that Hayward's EcoStar is in violation of three of Pentair's patents. In a preliminary hearing, the court found probable merit in Pentair's claims regarding patent infringement. At the same time, the court failed to see that any possible infringement would result in irreparable harm to Pentair. And, furthermore, in weighing matters of public interest in the matter, the court leaned slightly towards favoring Hayward.

As matters stand now, the preliminary injunction was denied on January 23, 2010, so Hayward, for the time being, can continue to sell and show its EcoStar product, but now the case moves to trial. Stay tuned.

A brief of the preliminary hearing can be found here.

Putting People First

I write a lot about tech stuff in this blog, but I was reminded recently about something more important than the minutia of technology: people.

Last week I was very impressed by a group of people that I meet with monthly. A long time member of my United Pool Association chapter (UPA #31) was recently diagnosed with cancer. He has made the decision to fight it and want to have his route to come back to. Unfortunately, he will likely not be able to work for at least 4 to 6 weeks while recovering from surgery and treatment. Since he has no employees there is no one in his company to cover his pools. So last Monday, he came to our chapter with an unusual request: help cover his pools while he undergoes cancer treatment. Without exception, everyone stepped up to cover his pools without pay. This was a shining moment for our chapter.

Pool Heater Chemistry

This blog post is about the chemistry of combustion, not the chemistry of the pool and spa water that is being heated.

Combustion:

Pool and spa heaters burn either natural gas—typically methane (CH₄) or propane (C₃H₈). Since both of these fuels are made up of the same basic stuff—carbon and hydrogen, just in different proportions, the combustion reactions are going to be similar. For the sake of simplicity, I will just focus on the combustion of natural gas.

Ideally, the combustion reaction is as follows:

CH₄ + 2 O₂ → CO₂ + 2 H₂O (ΔH = −891 kJ/mol (at standard conditions))

In other words, the combustion (i.e. oxidation) of natural gas yields carbon dioxide, water vapor, and a lot of heat.

Water vapor—a common byproduct and its disposal problem:

As noted above, one very common byproducts of combustion is water vapor: Put your hand a foot our two above a heater that is running and it will feel wet from the hot exhaust. If the heater’s combustion chamber and exhaust vent are hot enough, this water will remain vaporized long enough to exit the heater.

Interestingly, one of the key reasons that double wall vent pipe is recommended is not that it keeps the outside of the pipe cooler and thus safer, but that it keeps the inside hotter. A hot inner pipe improves its natural drafting ability due to the fact that hot air rises. The double wall pipe acts as insulation and the exhaust hot. The hot exhaust keeps the water in vapor form as it travels through the vent pipe. If you choose to use single wall vent pipe instead, the exhaust will lose its heat through the single wall pipe. As a result the exhaust will cool and the water vapor inside will condense while still in the pipe. This condensation explains why single wall vent pipe rusts more than double wall pipe.  

Low gas volume—a first obstacle to water vapor disposal:

If the volume of gas available to the heater is insufficient to provide for the minimum requirements, the heater may still light, but if it does, it will not burn as hot as it should. As a result, some of the water vapor in the exhaust will cool enough to condense before it rises completely out of the heater. This results in excessive rust-causing moisture remaining in the heater. Low gas pressure also produces an excessively yellow flame that emits a black soot that will stick to and eventually build up on the heat exchanger. Over several months or years, this soot will eventually block the exit of the exhaust. It will also trap excess heat in the heater causing it to become more efficient than it was designed to be. This efficiency is not as good as it sounds as the heater is destroying itself in the process (more on this later).   

Excessive water flow—a second obstacle to water vapor disposal:

Heaters are designed with a specific water flow in mind and have automatic valves that control the flow of water through the heater. Some of the better heaters will have two types of these valves. One type of valve is spring operated and is designed to produce a consistent flow of pool water through the heater despite the heater being used with a variety of pump sizes and with different amounts of restrictions due to the filter.

In addition to the pressure operated valve, there is often a thermally controlled valve that is designed to provide a constant heat exchanger temperature. If this thermally controlled valve malfunctions (or is not part of a particular heater’s design—it is absent from the Series One Laars, the Laars Lite, and the new Universal Forced Draft Hayward (UFD)), then the temperature of the heat exchanger will vary as the water heats up. If the initial water temperature is low, so too will be the temperature of the heat exchanger. And, if the heat exchanger is too cool, the water vapor from the combustion will condense on it and “rain” back into the heater. If you see a rusted burner tray on a Laars, this is probably the cause. Hayward claims that their new UFD heater is built so well, that this condensate “rain” will occur, but will not damage anything.

More than 84% efficient—a third obstacle to water vapor disposal:

Have you ever wondered why even some of the best heaters are “only” 84% efficient? Have you wondered why there is a major price jump upwards between these commonly used heaters and the rarely used “high efficiency” heaters? There is a good reason for this and it is all about the disposal of combustion water vapor.

As I said above, a heater’s exhaust needs to remain sufficiently hot for it to keep the combustion water vapor from condensing inside the heater. If the heater transfers more than 84% of its heat to the pool water, the exhaust becomes too cool to carry away this water as vapor. As a result, the water vapor from the combustion cools, condenses, and “rains” back into the heater. The condensing water (H₂O) combines with carbon monoxide (CO) to form carbonic acid (H₂CO₃). As a result, the condensate from a high efficiency heater has a pH that is typically in the 3.5 to 6.0 range.  

Efficiency in excess of 84% can come about by design—as in the Laars Hi-E2—or due to an unintended blockage that occurs within a standard heater. Heaters like the Hi-E2 that are designed to be highly efficient are manufactured with stainless steel burners and combustion chamber components to withstand the acidic condensate. Additionally, they have condensate traps and neutralization basins. These basins utilize limestone to neutralize the acidity of the condensate so that it can safely be disposed.

Standard heaters can inadvertently become highly efficient as the result of low gas volume—measured as low pressure with a manometer. Insufficient gas volume produces a flame that emits soot. This soot sticks to the fins of the heat exchanger thereby blocking the passage of exhaust gases. In blocking the exhaust, the soot slows the flow of the exhaust allowing it extra time to transfer heat to the water—thereby resulting in a highly efficient heater. Unfortunately, heaters that become highly efficient in this manner are not designed to handle the acidic condensate. As a result, the acidic condensate attacks the metal components and results in excessive rust and corrosion. These unintended high efficient heaters have only a short life left before they destroy themselves.

Formaldehyde—an occasional nasty byproduct of combustion:

There is one particularly nasty byproduct of combustion that sometimes occurs: Formaldehyde (HCHO, also written H₂CO) is one of these. Typically, formaldehyde is a short lived byproduct that quickly oxidizes in the extreme heat of the combustion chamber to form carbon monoxide (CO) and water vapor (H₂0). The carbon monoxide (CO) then oxidizes into carbon dioxide (CO₂). Sometimes, however, if conditions are wrong—if the combustion chamber is not hot enough—the formaldehyde doesn’t get oxidized and exits the heater as a smelly, eye-irritating gas. This mostly happens on low NO_x heaters.

The reason for this is that low NO_x heaters have blowers that are designed to lower the temperature of combustion—thereby reducing the formation of oxides of nitrogen (NO_x) that are known to form in small quantities at certain temperatures. The fans lower the combustion temperature and thus lower the quantity of oxides of nitrogen (NO_x) that are produced. Occasionally, some of the gas orifices on these heaters become clogged with spider webs. When this happens, only a fraction of the intended gas actually gets to the burners. As a result, the temperature within the combustion chamber is reduced even further. At this lower temperature, the formaldehyde doesn’t oxidize as it normally does in the combustion chamber and exits the heater. This results in a heater that smells particularly foul and will cause eye irritation. This problem is particularly prone to occur on low NO_x style RayPak heaters. See my YouTube video of how to correct this problem.  

Conclusion:

Understanding the chemistry of combustion can help when trouble-shooting a heater. The presence of rust—and its location—is a major clue never to be overlooked, so too are noxious formaldehyde odors and sizzling sounds caused by condensate “raining” down on the burners.

Heater Booms and Fails to Light--an unusual cause

Hayward H-series Heater

A couple of weeks ago I ran across a Hayward H-series heater (atmospheric, not low NOx) that failed to light. It would go through its start-up sequence: It activated the spark igniter and opened the gas valve and then fail to light. A couple of times it lit with a boom and then just as quickly the flame went out.

Orifice blocked by spider web next
to open (good) orifice

Usually this indicates that spiders have built webs that block the tiny orifice that supplies gas to the burners. When the orifice for the burner that is under the igniter is clogged, the heater often fails to light. Occasionally, enough gas from the other burners will build up in a cloud and drift over towards the igniter. In this case, it lights with a boom.  

Burner with openings blocked by rust

But today, that was not the problem. As the picture shows, rust deposits have built up on the burner and are blocking the openings. The rust was particularly bad on the burner that is under the igniter.

The rust came about because the heater is "condensing." This happens when condensation forms on the heat exchanger (located directly over the burners). The condensation then drips down onto the burners. You can often hear the effects of a condensing heater. It will sound like water being flicked onto a hot skillet.

The way to fix the problem is to replace both bypass valves in the inlet/outlet header. There is one bypass that operates on pressure and one that relates to temperature. Either could cause this problem and since it takes a good deal of labor to get in there, it is better to replace both. Then, after fixing the cause, fix the damage by replacing as many burners as necessary.

Using an Intelliflo pump with and AquaLogic or ProLogic Control System

Even the newest versions of the Hayward / Goldline AquaLogic controller (2.85) are not setup to select different speeds on the Intelliflo Pump.

It is possible, however, to get the two to work together using the first generation Pentair IntelliComm.

Programing the Pump:

First, set up four distinct speeds on the pump. This is straight forward on the old style 4 X 160. If using a newer menu driven pump set up the speeds in the External Control menu.

Strategy for setting up the speeds:

When using a variable speed pump with a control system, be aware that the controller will often call for more than one speed at a time. The IntelliComm resolves such conflicts by switching to the highest speed number (1-4). Depending upon how these are set, this may or may not actually be a faster speed. Indeed, in once case (if you follow my strategy below), it will not be a faster speed.

Speed 1 will be your default speed that comes on when the pump is turned on. Set this speed to an appropriate rate to operate the automatic pool cleaner (if one is present).

Speed 2 will be your low/economy speed. If both speed 1 and 2 are activated at the same time, the pump will run at the slower speed 2.

Speed 3 will be used to ensure that your heater has adequate flow should the heater come on while the pump is running in low speed (speed 2). If both speed 2 and 3 are activated at the same time, the pump will run at the faster speed 3.

Speed 4 will be used for the spa jets. This will ramp up the pump speed to its highest setting.

Programming the Controller

Setting up your time clocks:

When you set your timers, you will set the filter pump for the total time that you want the pump to run. This should be about 12 hours (8am-8pm).

Within those hours, you will set a time to run the low speed. You could go into the Configuration Menu and set it up as a two speed pump and use auxiliary 1 or 2, but I will assume that those are already being used for other things and are thus not available. The better alternative is to use Valve 3. I recommend programming Valve 3 to operate the low speed during the middle of the day. (I recommend 10am-7pm.)  This way the pump only runs on high for 2 hours in the morning and 1 hour in the evening. During the peak usage of mid-day, the pump runs on low for 9 hours. Running the pump on low for 9 hours will use about the same amount of energy that it would to run it on high for 1 hour, but by running it on low, you have continuous filtration and chlorination when the sun is up and algae growth is more active. The longer run time for your chlorinator prevents dips and spikes in your chlorine level.

Wiring the IntelliComm

Wire the 240v power supply for the variable speed pump directly to a breaker. You do not want to use the filter pump relay for this. (It will be used to activate speed 1).

Power the IntelliComm with 110v (terminals 1&2). I recommend using the same breaker that powers the Aqualogic board.

Rewire the high voltage side of the filter pump relay to send 110v to terminals 3&4 of the IntelliComm. This will call for speed 1 (high speed).

Plug a valve actuator cord into the Valve 3 socket. Connect the black wire to terminal 5. Connect either the red wire or white wire to terminal 6. Use whichever one has power when Valve 3 is activated. This will activate your speed 2 (low speed).

Inside the heater connect one conductor or a two conductor thermostat cord to the low voltage ground side of the transformer and the other conductor to a place that has 24vac when the heater calls for heat. Connect this thermostat wire to terminals 7&8 of the IntelliComm. This will activate speed 3 (heater speed).

Splice into the wire going to either the suction valve or the return valve. If you would like to ensure a strong waterfall if the spillover feature is active, then splice into the wire for the return valve. Again, as before, you will connect the black wire to terminal 9 and connect either the red or white (whichever has power when the spa is on) to terminal 10. This will activate speed 4 (spa jets).

Finally, attach the yellow wire on the variable speed pump cord to terminal 11 and the green wire to terminal 12. Plug the other end of this cord into the data socket on the variable speed pump.

Using the system

Once it is programmed, you can forget that it has different speeds. Just use it as usual and the pump will switch to the appropriate speed without the user having to think about it.

Silicone Nitride Igniter

I ran across an interesting problem earlier this week. I was working on a newer style Hayward UFD (Universal Forced Draft) heater. 

It would try to light, then--after three attempts--it would fail and give an IF (Ignition Fail) error.

Many problems can cause this error:

• A bad flame sensor
• A bad  ICB (Integrated Control Board)
• A bad HSI (Hot Surface Igniter)
• When there is first a call for heat, the ICB sends power to the HSI. If the current draw of the HSI is sufficiently out of range, the board will immediately trigger an IF error and the start up sequence will stop at that very point. 
• If the HSI passes this initial self check, then the fan will come on and hopefully activate a vacuum switch thereby proving to the ICB that the fan is working. At this point, the HSI will start heating up. If you measure the current draw of the HSI using a clamp-on amp meter that is placed around one of its wires, you will initially see it draw about 3 amps, then slowly draw less and less current until it is drawing a pulsating 1-1.5 amps (the needle will actually pulsate up and down).
• The gas valve will then open for 4 seconds and the HSI should ignite the gas.

If the heater still fails to light it could be for several remaining reasons:   

•  Spider webs could be blocking the flow of gas to the burners. It is quite common for a spider to build a web that will clog up the gas orifice that supplies gas to the burners. These must be unscrewed from the manifold for cleaning. Poking a hole in the spider web and pushing it back into the manifold with a wire is a short term solution at best and at worst, will result in a roll out hazard later on.
• It is also possible that the heater fails to light because the gas valve isn't opening. Use a manometer on the manifold side of the gas valve to confirm that the gas valve opens and is supplying the proper amount of gas for combustion.
• It is also possible that you STILL have a bad igniter. Even though the igniter passed its self test and even though it draws approximately the correct amount of current as shown using the clamp-on amp meter, and even though it gets hot the the touch, it may still not be getting hot enough to ignite the gas. I found this to be true earlier this week. The HSI that was in the heater was simply not getting hot enough. I checked the resistance of this igniter against that of a new igniter. The existing (and bad) igniter had about 37 ohms of resistance. The new (and good) igniter read had about 15-16 ohms of resistance. 

A little history of Hayward's Silicone Nitride Igniter:

Some years ago with the advent of Low NOx (low nitrous oxide) heaters, many manufacturers switched from using pilot lights to ignite the burners to using direct ignition from a red hot glowing hot surface igniter. These work much like the electric heating element does on a stove or toaster. Just like a toaster can light your toast on fire, these hot surface igniters can light gas on fire.

Hayward's first shift away from a pilot light was to use direct spark ignition of the main burners. They then switched to using the same type of fragile hot surface igniters Pentair, StaRite, and Jandy still use.

These fragile igniters are made of Silicone Carbide. This material is very brittle. Replacement ones come packaged in foam rubber to prevent breakage during transport--and many of them still break during shipping. Installing them is a bit like playing the game that old game called Operation--one careless move and the igniter is broken.

Hayward chose to address this problem by switching to a more robust igniter made of silicone nitride. During their technical training seminars they show Power Point slides where these igniters have been hammered through a 2x4. This strenght is impressive for those of us familiar with the fragile-as-glass silicone carbide igniters. Nevertheless, despite their strength, they still fail. And, when they do fail, they can fail in ways that show no visible signs of failure. Such failure makes troubleshooting a little harder at times.