R494A stack relay

[JW]

I have an old oil fired water heater which is going out on reset at the stack relay flame sensor. I can't seem to find a replacement for this relay R494A. Can I convert this to a photo flame dector relay system. I found one in Grainger page 3473 not sure if this would work. Item # 2e727. Any ideas appreciated...Thanks

[HayZee518]

The photo flame detector operates off the oil flame it sees. The stack relay operates off exhaust gases in the stack.

[HayZee518]

I went to do a search using "honeywell stack relay" and came up with this number --> RA117A1047 from their site. Its a stack relay for $102.00