by Sean Griffin, May 7, 2009
Minor heater repairs can sometimes become somewhat complex. Diagnosing the problem can become its own problem, and lf major repairs are necessary, can become lengthy and involved. When working on any type of heater you are dealing with an appliance that involves electric, gas/oil, and water. These components are designed to remain separate and should remain so to avoid personal and/or property damage. Major heater repairs should always be performed by a professional. Follow all guidelines and recommendations set forth by the manufacturer to ensure your safety and the longevity of your pool heater.
Major heater repairs consist of (and are not limited to) converting gas source, replacing burner tray (#30 below), and replacing the heat exchanger (#13 below). Often times when attempting to diagnose and fix the problem, the remedy listed in the manufacturers diagnostic guide leads you to “refer to qualified service personnel”. When possible contact the manufacturer regarding your exact heater make and model, they have staffed a technical support department to help answer your questions. Look on the inside panel of your pool heater for the model number and serial number before calling. Also helpful are the online Owner's Manuals for pool heaters. Visit the links below to find your pool heater owner's manual.
The heat exchanger is where your pool water is pushed through copper finned tubes. The flames below, in the burner tray, heat these tubes and the heat is "exchanged" to the water as it rushes through the tubes. The heating tubes or coils are directly above the heat source and in turn heat and warm the water.
A common problem with the heat exchanger is improper ventilation due to corrosion or debris. When the space between the coils become blocked with soot or lime deposits, the heater cannot exhaust itself fast enough through the top of heater. Advanced stages of blockage in the air spaces of the tube fins may result in flame rollout. When this happens, this typically melts a wax pellet inside of the fusible link, thus breaking the Safety Loop circuit. Before replacing fusible link/rollout switch please first correct ventilation/exhaust issues by cleaning corrosion and/or debris off of coils. In most models the coils can easily be accessed with minor disassembling from the top down. The best way to the clean heat exchanger is to use a wire brush.
On occasion a repair might call for the replacement of entire heat exchanger. If the pool water has been "aggressive", with low pH and Alkalinity this can lead to pinhole leaks in a heat exchanger. This is not covered under warranty, so watch your pool water chemistry! Most commonly, heat exchanger leaks are in the seal between the heat exchanger tube set and the front and rear headers. This can be remedied as simply as adding a new gasket(s). Common this time of year is leaking headers, either front, rear or both. If you left water in the heater over the winter and it got below 32 degrees, you may have a freeze damaged header on your hands. This job is not too difficult, just remove and replace. We have pool heater parts here at POOLCENTER.com.
Swapping out entire exchanger means more disassembly but can be achieved with a little know how and some patience. There will be some plumbing required - but don't sweat it! Just need a few slip couplings and pvc fittings and some hand tools, including a hacksaw. Please consult your pool heater owner's manual for the complete procedure. This job does not require any gas fitting. First, we need to cut the two pipes going in and out of the heater. Then dissassemble from the top down to expose the entire exchanger. The entire heat exchanger can be lifted out in one piece to a table for dissasembly. Remove both headers from the existing H.E. and with fresh gaskets supplied, fit them back onto the new H.E.. Place the entire assembly (assembled) back into the "box", and reassemble the top. Make sure any external draft hoods or outside ventilation is reassembled correctly. Finally, re-connect the plumbing or the pipes that go in and out of the pool heater.
Proper exhaust is very important for a heater's performance, but it also needs to vent away from houses and out of pool equipment rooms. Gas and Propane Pool Heaters produce carbon monoxide, which can be fatal.
Pool Heaters are designed in a very similar manner to a gas household hot water heater or gas furnace. Gas pool heaters using a gas source, natural or liquid propane, introduce heat converting gas into a controlled flame that is released through a burner tray. The burner tray will heat the coils at the heat exchange in turn heating the water. The flame from the burner tray is released from small orifices . These orifices can become obstructed by very small nests or webs from very small critters. It's a good idea to visually check your burner tray every year to make sure debris is not laying on top of the burners. This requires getting down very low, and getting your eyeballs right up on the tray. Some heaters have an inspection panel that can be lifted or removed to view across the top of the burner tray.
Gas is converted into flame using a pilot which is part of the burner tray assembly. The positioning of your pilot is vital to ignite the burner tray. The pilot receives gas from the internal gas valve which will open if all safety switches are functioning properly. The Gas Valve will not release gas to the burner tray unless all Safety Loop circuit controls are working properly.
Burner Trays can be removed fairly easily. First, shut off the gas coming into the heater, and remove the gas pipe from the gas valve. The burner tray will slide out after removal of a few screws. You will need to disconnect some of the Safety Circuit wiring from the gas valve. use masking tape to mark where they connect, or draw a quick map. A badly deteriorated tray or weldment, as Laars called it, may fall apart as it's being removed, so be gentle when removing the burner tray. All parts on the burner tray can be replaced individually, so you may not need to replace the entire burner tray, except in cases where you need a gas valve and a pilot assembly.
Conversion to another gas, for example, converting a Natural Gas heater to operate on Propane Gas, requires changing of all gas orifices. Some manufacturers have a simple kit, whereas Laars/Jandy require a replacement of the entire burner tray, which may be a safer and easier repair to make for the average do it yourself pool owner. Always consult the manufacturer or the owners manual to read proper burner tray installation considerations. Working with gas can be dangerous. When making gas connections always test for gas leaks by spraying all connections with a soapy solution. Bubbles forming indicate a leak.
Next step ~ fire up the heater, fire up the grill, and enjoy your swimming pool! One more tip - using a solar blanket or pool cover when not using the pool can save a lot of money and energy, especially at night!