I have a Raypak 400kbtu propane heater acting up. When I turn it on it calls for heat and the burner fires normally, after a few seconds, the flame goes out briefly then comes back on for a second or two. The heater continues in this fashion. No error code is given. I have replaced the gas valve, and have confirmed that I am getting 24V to the valve. I've taken the header off and confirmed that there is no calcification (good to know). Any thoughts on other causes? faulty HL switch? Faulty pressure switch?
Thanks for any help