• A fireman’s switch is a device installed in a time clock. It turned the heater on 30 minutes after the circulation pump went on and turned the heater off 30 minutes before the circulation pump went off. This was to allow the water to cool down and not damage the plumbing lines. ALL Hayward heaters have Fire Tile, which dissipates the heat immediately, so a fireman’s switch is not required.
• NOTE: Gas fired heaters should be diagnosed and repaired by trained personnel.
  

• Current year model electronic heaters are dual voltage and can operate on 120VAC OR 240VAC. Millivolt heaters do not require an external power supply. ABG heaters require 120V ONLY.
• NOTE: Gas fired heaters should be diagnosed and repaired by trained personnel.
  

Recommended H-Series Heaters for Swimming Pools.

Determine the pool surface area by multiplying the length of the pool in feet by the width. Use the chart above to determine the heater size for your pool.

A note about heater size: A pool heater should heat the pool, on average, one degree an hour. Once the heater is sized to the pool, stepping up one or two sizes will decrease the time to heat.

CAUTION: If you are replacing an existing heater, the new heater size is limited by the diameter of the existing gas supply pipe. Gas pipe is sized according to BTU’s required. Installing a larger heater than the existing pipe can supply will result in a sporadic or non-operating heater.

• Hayward heaters can be converted to use NG or LP. The heater may require a new gas valve, burner orifices and/or air restrictor plate upon conversion. Hayward offers conversion kits through your local Hayward dealer. A licensed or certified gas professional will need to perform the conversion.
• NOTE: Gas fired heaters should be diagnosed and repaired by trained personnel.
  

• The best way to drain the H100ID1 above ground pool heater is to disconnect the gas and plumbing lines and tilt the heater so all the water is removed. Please make sure to close off the water supply and turn the gas supply off prior to disconnecting the plumbing. You can also use an air compressor or shop vac to blow the water out of the plumbing lines

• The valve seat gasket inside of the valve may have become worn or loose. If this is the case, you will need to replace the gasket. With the pump off, remove the cover screws of the valve.                                                                                   NOTE: Mark the top and bottom of the valve with a marking pen. It's very important that you do not change the location of the cover when re-assembling. Some newer valves will have a flat spot along side one of the cover screws. When re-assembling, align the flat spots.  
• GENLTY remove the old gasket and glue, ensuring the channels are clean and clear. Use 3M adhesive, part number SPX0710Z9, or crazy glue**. Lay a bead of adhesive into the channel where the gasket sits. Place the flat side of the gasket into the channel. Apply pressure to firmly seat the gasket and let dry for 24 hours or contact your Authorized Hayward Dealer for repair. **Crazy Glue – Use caution when using crazy glue. You will have only ONE chance to seat the gasket

• A dirty filter maybe the problem. When the filter pressure rises 8-10 PSI over the clean starting pressure, it is time to backwash or clean the filter
• If there is algae in the pool, it maybe clogging the filter, keeping the pressure high. The filter cannot kill algae. Contact your Authorized Hayward Dealer for proper chemical applications.
• If the filter pressure continues to run high with reduced water flow to the pool, the pump may be moving more water than the filter is designed to handle. Check the flow ratings of both the pump and filter to ensure they are sized correctly.
• You may have a blocked or plugged return line. Contact your local Hayward dealer for service.

• The Diatomaceous Earth (DE) filter contains filter elements that are either curved grids or Flex tubes (long finger-like tubes). They are covered in a fabric on which the DE forms a coating. The DE acts as a filter by permitting water to filter through the DE and leave the impurities behind. The DE filter has the ability to filter out microscopic particles.

• D.E. filters filter the water down to 1-3 microns, every time the water passes through the filter. Maintain a balanced clear pool and this will reduce incidents of rapid pressure rise. One possibility is that the filter grids or Flex tubes are clogged with minerals or oils. You should clean your grids once a year, or season, with a degreaser and if needed an acid bath. Minerals and oils embed themselves in the fabric of the filter and reduce the available surface area used for filtering.
• If too little DE is added during pre-coat, debris and particles will embed in the fabric. Cleaning with a high-pressure hose, NOT A POWER WASHER, may be needed to remove the grids. If cleaning does not work, then replacement is the only option.

• When a DE filter is properly backwashed you will be removing about 80-90% of the DE. Remaining DE may be clumped in the corners of the filter or caked in the middle. This is common. After backwashing, new DE must be added to the filter. Add the entire amount of DE the filter recommends. If you see DE returning to the pool, vacuum it to waste, after it settles. The next time you backwash and recoat, decrease the amount by 1 pound. This will avoid DE going back into the pool.
• The only way to remove the entire DE is to disassemble the filter. The next time the filter is disassembled and cleaned, pre-coat with the entire quantity of DE.
  Remember, the filter should be taken apart and cleaned at least once a year.