I have the Hayward Gas Heater H Series (installed August 12/2010) and notice the smell of gas whenever I Ist turn it on (and sometomes longer). I have never had to run the heater more than 1 or 2 hours to get the pool temp to rise 5 degrees. (from 75 up to 80)
I contacted the installer and he said that it will have a smell for the 1st 30 days or so as silicone etc burns off the new heater. I think that it smells like gas and I also contacted Hayward - they told me that yes there will be a "smell" ... If I am concerned I should contact a liscensed Gas technician.
It has 84 % Efficiency and some Mechanical Engineers tell me that that is just the smell of the 16 % in-efficiency. My gas furnace is 90 % Efficienct and I notice a similar smell from the horizontal exhaust pipes at the side of the house.
Anyone else notice this "smell" ??