The burner controls on modern furnaces rely on proper neutral grounding/bonding for the flame sensors to operate properly. It's likely code 45 is for control lockout after ignition was not proven.
Rich
PRA
Make sure your relief valve is set higher than your pressure reducing valve, oil running through the relief will generate heat quickly. Also check the accumulator pre-charge.
Rich
PRA
Your flame signal will be in the µA (micro-amps) range, that could explain your signal loss at a greater distance according to the Fire-eye data sheet:
The wire type and its capacitance (picofarads or microfarads) to ground may cause low signal problems,
so a grounded shield may decrease the...
I've used Southwire's SIMpull No. 2 AWG THHN in the past with good results. http://files.engineering.com/getfile.aspx?folder=53e95438-bd7d-414a-bebd-cbdbafcf945c&file=XTEInterfaceServlet.pdf
You will likely have to set up a virtual machine on your Windows 7 or 10 machine to run XP or older. Then you can install Microwin on the virtual machine.
I'm not 100% certain of that meter, but if the thermocouple connects directly to the meter, it has cold junction compensation, so by shorting the leads together you will measure the temperature of the cold junction.
Only three conductors in conduit do not require derating. For more than three conductors see Art.310.15B2. For ambient temperature corrections see Table 310.16 Correction factors.
DId you measure the charging current? IF you are only drawing 2.5 amps then you are not replacing at 5 am hrs. That could be why it takes twice as long to charge.
except as permitted in 356.100(5)
That should have been 356.10(5)which refers to support 356.30 : every 900mm (3ft) and within 300mm (12") on every box,fitting,etc.
per 2002 NEC 356.12(3): Uses not permitted, lengths longer than 1.8m (6 ft) except as permitted in 356.100(5) or where longer length is approved as essential for a required degree of flexibility.
If the relay is switching often, the repeated make/break can cause excessive contact heating and therefore welding.
You may need to oversize the relay as you would a motor starter for jogging/plugging operation.