New home fellas, inherited a pretty old heater. It hasn't worked reliably since I bought the house. So far, I've:
1. Ran high pressure gas over, installed a regulator at the unit. Previous tech said line wasn't getting enough pressure. Probably good I did this anyway, even though it didn't fix the problem.
2. Replaced the hi-limit sensors (both of them).
The unit is in bad shape cosmetic-wise. Lots of rust, dust, dirt, all through it. I'm going to take some compressed air to it in the morning, but thought I'd share some pics and see if you guys could point out any other possibilities. Any help is greatly appreciated.
Video of it shutting off (with buzzing noise): http://www.youtube.com/watch?v=7C6f12XLhRM
Update: Did more research on the forums here, looks like I may tackle the flow valve next. AND, uh oh. I have yellow flames, looks like I definitely need to clean it out per the maintenance instructions.
"Visually inspect the main burner and the pilot burner
flame. The normal color of the flame is blue. When
flame appears yellow, burners should be inspected
and cleaned; see Figure 10"