I need a C-wire for my thermostat but my heater only has R and W connectors (red circle). On the schematic on the heater, up top (red arrow), looks like:
5 is 24V Gnd (bit hard to read but i've double checked that's what it says) and
6 is 24V
I assume the 6 24V is the same as the R connector.
So would it be safe to assume that 5 would be the equivilent of a C-Wire?
UPDATE: after some hunting I managed to locate the service manual :) I've included a page with the circuit overview:
And have revised my though on a candidate spot to tap the C-Wire. Based on the text in the green box and the comments, I am assuming the top right of the middle connector along the bottoms (with the green arrow) would be the best location.
Update #2: I've now located the block diagram for the S8065 INTERMITTENT PILOT MODULES (block at the top of the picture). And from it, one can clearly see that connectors 2, 4 and 5 and joined together. I confirmed this with a continuity test and they 2, 4 and 5 and the chasis of the unit are all connected.
I then checked the potenital between these points and the R connector and it was 29.5VAC.
Just one last question.. Is it normal that the voltage is 29.5VAC, this seems quite a bit higher than 24VAC. I just wouldn't want to fry a modern thermostat!