A short while ago I had a rapid on-off cycling of my Intertherm RSH-MS-065 fuel oil furnace I suspected was the T-Stat. Anyhow, I replaced said T-stat, as I kinda wanted to upgrade the appearance anyhow, and the furnace seemed to work OK the 1st couple times. Should be noted that I am in Florida so it does not get used very often or for long periods of time. Anyhow 2 days ago I turned it on to remove the night chill from house and although furnace light and ran fine I could hear the relay inside the flame control box clicking, oddly the furnace stayed lite and fan ran . Today I tried to run the furnace and it would run for a short bit and cycle on and off. I think it is control unit because it does not just shut off the burner, sometimes it cycles the blower fan and everything like you are killing the power to the entire unit. If it was the flame detection part of the system it would still run the blower fan (like in the cool down/purge) right? I jumped across the T-Stat wires and still did it, that removes the T-Stat from the list of possible issues. Anyhow it is a White&Rogers TYPE 668-410 control box and I found one place on the web and it looks like it has been preceded by a 668-415 box. I saw there are other types of burner controls that appear to be solid state, can I upgrade my control unit?
Well, there is no oil heat out here, so I can't be a lot of help.
White Rogers lists the 668-430 as the replacement for your control.
You mentioned 668-415, and White Rogers also lists that as obsolete, with the replacement being again the 668-430.
The second link I posted above is installation and trouble shooting, and may be helpful to you. Are you sure the new thermostat you installed is compatible with your system??
I am sure it is not the thermostat, it did similar thing prior to me replacing it. I figured the new t-stat would not solve my issue but wanted to update it anyhow (appearance). Furthermore, I also jumped across the two t-stat wires and furnace still acted the same. I will check out the troubleshooting link, thanks.
I received the replacement oil burner control module (WR 688-430) and it has a group of wires that my old control unit does not have. They are black, white & orange and the schematic says they go to the burner ignition transformer and limit switch. Do I even have these since my old control unit does not use these, (Old one just hooked to T-Stat and the flame indicator). Can I just wire nut them and leave unattached? Thanks in advance.