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Well-Maintained Heater Extends Swim Season

by Doug Walsh

As the summer swimming season grinds to a close over the next few weeks, many poolowners will be looking at ways to extend that season as long as possible. Short of messing with Mother Nature, the obvious answer is to fire up the pool heater, warming the water to a comfortable swimming temperature.

Even if the heater was thoroughly checked out in the spring and operating effectively, summer’s inactivity may well have left it in need of a fall overhaul. Regular use of the heater would ward off problems such as corrosion, windblown dirt and pest infestations, but yearround firing of the heater when warming the water isn’t called for makes little sense from either an environmental or economic standpoint.

However, when it is left idle while the summer sun does its heating work on the water, the unit can become a potential home for ants, rodents, and spiders which can block electrical contacts or gas lines.  This is especially true in areas that experience a large amount of rain followed by a hot summer.

For those service professionals lucky enough to have one of the new digitally operated, self-diagnostic models, most of the troubleshooting is as easy as pushing a few buttons on a keypad.  In the event that a problem arises, the digital display easily points out the problem and the probable cause.

One manufacturer even likens its new digital unit to having a service technician built into every heater!  But thousands of older-model heaters remain in service that still need problems diagnosed the old-fashioned way.

Before beginning any heater repair, be sure to take all necessary safety precautions.  Start by verifying that the unit is turned off and disconnected from any source of electricity.   This way, the heater cannot accidentally restart should the wrong wires touch during the trouble-shooting process. In addition, make certain that the unit is properly cooled down before touching hot components.  Remember that this is a piece of equipment that generates a tremendous amount of energy, which can transfer over to the metal components and remain hot long after firing.

Veteran heater trouble-shooters know that the first place to look at when a heater is not firing properly is often not the heater itself.  The culprits are far more likely to be dirty filters and restricted water gas flow.

If the filter is dirty, simply backwash and fire up.  A blockage somewhere along the water system calls for a check for clearance in the main drain and skimmer, the pump lint pot, the pump impeller and the valves.  Gas lines should be checked for obstructions from the source to the equipment.

And never overlook the obvious.  The system may not be set to run for long enough cycles, which may just be a simple matter of resetting the time clock.  Or the thermostat may need to be set higher. The basic, step-by-step trouble-shooting process could prove that a faulty thermostat or one that is out of adjustment is the cause.  In that case, test the unit and replace the thermostat as needed. Analysis may uncover that the pressure switch is inoperative.  Given a clean filter, test the switch and replace it if necessary.

Since service professionals should also heed some lawyerly advice: it is far better from a liability standpoint to replace faulty components rather than attempt to repair them.  Tinkering with components may well violate the manufacturer’s warranty and limit the manufacturer’s liability.

Of course, if a component has failed, professionals in the field should try to pinpoint the reason for the failure.  Otherwise, when the component is replaced, it may well fail again. If all systems appear to be functioning properly, the heater could well be just too small to do the job.  In that case, consult a heater-sizing chart, and advise the customer that the unit should be up sized. If the heater is sized correctly, the fault could rest with an undersized gas system.  Check the gas-pipe-sizing charts, and upsize the plumbing.  Also, check the gas meter and the supply shut-off valve for proper sizing as well.  Sometimes, it may be necessary to contact the local natural gas company to determine flow problems at the homeowner’s supply source.

One other non-heater-related problem could be the pool’s water level, which may be too low for consistent heater operation.  The answer may be to raise the water level, check for system leaks and possibly install a water leveling device.  Improper ventilation is the cause of many heater problems.

One of the symptoms is sooting — black carbon buildup on the heat exchanger.  The carbon starts as a dirty, black coating and builds up to the point where hunks of coal burn and break off, failing onto the burner tray.  The burners become clogged, shutting dow the heater’s full capacity and causing the heater to smoke.

While cleaning the burner tray and components can temporarily solve this problem, the ventilation needs to be fixed to the solve the long-term situation.  Check the installation for proper clearances and/or venting.

Sooting could also be caused by excessive water flowing the heater. In that case, the solution is to correct the water flow and clean the heat exchanger.  Also, the air inlet or “venturi” for the burner could be plugged.  Once again, the solution is to check for debris, dirt, insects or small animals in the burners inlet’s throat or venturi and clean them.  If the burner will not stay lit, the problem could be low gas pressure.  Check the gas pipe and meter sizes and/or adjust gas pressure as needed.  Then again, debris, dirt and those pesky insects may be just plugging the burners.  Clean them, and the problem may be gone — that is, until those conditions return.

Following are other common areas that service pros should look at if problems persist:

  • The heater’s manual bypass could be out of adjustment and simply require some minor fine tuning. In that case, simply check for the manufacturer’s guidelines, and make the adjustment.
  • The unit’s switches — the pressure switch or high limit switch — may be out of adjustment.  Adjust or replace the switch in question and verify that the heater shuts off when the system’s pump shuts off.   If the customer complains about the heater making knocking or whining noises, the unit could be still trying to fire after the pump shuts off.  Adjustment or replacement of the pressure switch should do the trick.  The cause of the noise may also be the pressure switch itself, which may require a minor adjustment.
  • Debris or other restrictions may be blocking the system.  Remove the blockage and flush the system.
  • Scale built up in the heat exchanger tubes could require descaling or replacement of the heat exchanger.  Check water balance, its the cause of the scaling situation in the first place. Major heater manufacturers — including RayPak, Pentair and Jandy (Laars) — have scheduled a full slate of factory-authorized seminars across the country beginning this fall and running through the spring.In addition to becoming certified to handle warranty work, service professionals gain valuable knowledge to work on installation, trouble-shooting and repair work.  Most manufacturers even provide spare parts and tool kits necessary for doing trouble-shooting and minor repairs at their factory-sponsored seminars.

    Service firms should also consider that when they continually are called out to work on older units in disrepair, tit may be time for a replacement with a newer unit that not only works better but is more energy efficient and easier to maintain.  Today’s energy-efficient units could well pay for themselves with lower gas and/or electricity costs.  At the same time, they monitor their own activity and report malfunctions before they have the opportunity to develop into major problems.

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