I'm a first time pool owner and my Raypak pool heater is having some issues firing up. When I turn the heater on I see CFH, then SPK. Once I see SPK, the heater will make a buzzing sound as though the heater is trying to light, but it doesn't light. The heater WILL work from time-to-time, but not consistently. I have a pool service guy who looked at the heater, and he thought that a gas tube that runs from the gas valve to the ignitor was the problem. He used my air compressor to shoot air through the line, but the heater still works when it wants to. Any suggestions/ideas as to what I can look at next? I have come to realize very quickly that my pool guy isn't too familiar with the equipment, but is good at keeping the water clean (he even admitted this to me).