Waste Oil Heater Forum - Your definitive source for burning waste oil for heat.

Hi I have a cleanburn 175 with a CB 525 gun. Installed it in 09 and ran trouble free for the first 5 years.  Now   the unit will run forever but the oil pressure creeps downward with time.    setting it back at 2 psi  i find that when the unit reaches temp then restarts later the pressure is too high.  the longer its off the higher it may be. 5 psi will make the unit sputter and smoke and go on safety . but pressure is steady.  lowering it to 2 psi gets it running fine, but after a several hours  pressure goes as low a a half pound.       set it a 2 psi and we are good as long as the unit never cycles.  This is an on going problem and  I have changed the regulator, Nozzle. cleaned the heater block and all filters.  Pump  maintains 25 psi at all times.  With an open bleeder there is a full flow of oil without a bubble  any Ideas would be helpful