Hello all! I need help troubleshooting my Riello 40 F3. I Cleaned the boiler as usual this year and the F3 won’t fire up properly. I replaced the oil filter, replaced nozzle, cleaned everything, etc. My F3 is configured as dual line to pump connected to a tiger loop for air elimination. I also have a field controls auto damper wired to F3 which I confirmed is opened up. When I power the F3 up everything sounds normal. The blower goes on, hydraulic air shutter opens. I think I can hear oil spraying but I get no ignition, then it shuts down. I thought maybe air in the line so I opened the pump vacuum port and definitely see fuel coming out. I tried the (two line) pump purge, no luck. I opened up the boiler door and I feel oil around the nozzle. I checked the electrode connection and the primary control, it all looks clean and in order. I briefly got it to fire up, but it is only temporary, like 1-2 seconds at a time. I opened the boiler port to observe the flame and observed some burning after the F3 went off; I believe oil is spraying well, but the ignition is not keeping it burning. I believe it is not getting spark at the electrode and nozzle. I’m not sure how to troubleshoot from here. Any advice appreciated. Thanks

Hello, On my old oil furnace, I have a Honeywell L4006A3X042 immersion aquastat (actually two- one for high limit and one for low limit). I'm thinking the high limit one is on the way out. Before I replace it, is there a way to check it with a multimeter? Thanx.