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

Burner rebuilds are normal heater maintenance that Clean Burn recommends every year along with a service kit. I say every 2-3 years is plenty good and sometimes you can go longer. Over time the preheat block will sludge up and bake especially if the power is left on all year. So if you were a customer of mine the first thing I would do is a burner rebuild and install a service kit.   

Is it supposed to sit in gas for that long btw? Or is a week necessary only when it's particularly dirty or something?

When I do burner rebuilds I use solvent and a ultrasonic cleaner. Before I got the ultrasonic cleaner I used just straight solvent and gun cleaning brushes. I would just get after it until clean. I do not like to use gas due to flammability issues.   

Go with a Lenz filter then you never have to buy another filter again. They are stainless steel washables and last forever.

#70158 service kit will include nozzle, electrodes, nozzle holder o-ring, solenoid/regulator guts.

I would put the pump on top of the tank and replumb the suction side. I will take a picture of a setup to show you how to make it simple and easy.

Since you need to clean ash from it every so often I would not use sand. If anything I would use fire brick.

Try clicking on "attachments and other options"

Remove the heating elements and all plugs. Make sure you heat up the plugs first to make removal much easier. Then solvent and gun cleaning brushes. Make sure to get all passages/nooks/crannies spotless before putting it back together. Use a medium strength thread-locker on the plugs/heating elements tighten till snug.