Protector Relay

The only difference I can see between the two controls is that the R8184G4082 contains a set of dry contacts, which means an unpowered switch, which can be connected to an alarm. Let’s say you had a vacation home, and the home alarm and monitoring system had the capability to monitor the burner. These dry contacts would be used to allow the burner to communicate to the monitoring system that a misfire has occurred. In my years of doing this I have never run into a situation where this has been the case.

Both are primary burner controls. This is confirmed by the fact that they both begin with R8184G. What is different is the backup number 4009 vs 1427. Unfortunately, due to the age of your control I can’t find any detailed information on your specific version and what the backup number on your control indicates. A qualified licensed burner technician with knowledge of the appliances wiring schematic and ignition cascade could use this control. But the controls may not be identical so it should only be done by a trained professional.

To give you a definitive answer I would either need to be on site or at least in possession of the systems electrical schematic. In the absence of that I would say no this would not be a suitable direct replacement. The model you reference R8184M is unique in that it comes equipped with a 24-volt 40-volt amp transformer. That strongly suggests to me that this appliance has a low voltage control strategy that requires a lot of power. A professional with knowledge of oil equipment and your system could probably rewire the system by using a more conventional primary control and separate transformer to accomplish the same thing. But given that you asked the question that suggests to me that you are not that person. Therefore, I would recommend you use the exact same control.

That is not a complete Honeywell model number. In fact, I wonder if it could be a date code. Honeywell model numbers almost always begin with a letter followed by four numbers and then a letter. Often there are then four additional numbers called the back up number. The only Honeywell number I know that contains 4185 is the M4185B, that is a different control used for a completely different purpose.

No. This control, the R8184G4009 is not a replacement for R8182H. They are distinctly different. The control you reference performs multiple functions that this control does not.

Chris, your answers are very good, knowledgeable and precise. I made one more discovery with this replacement upgrade. I had to run a jumper across the TT terminals as my boiler responds to the thermostat/ zones through the aquastat. Thank you!

Yes, the only difference is that this newer version has the additional option of TT contacts. As your earlier version did not have them, the use of these contacts is not part of the wiring logic designed into your system. You won’t use them.

Yes it should in the vast majority of installations. However they are not exactly the same as your version of the R8184G with the backup number of 1138 is fairly old.

As you will notice the backup numbers are different. Meaning the last four digits of the model number. 1286 vs 4009. Sometimes the backup number identifies a key difference. But more often than not by my experience it simply identifies the unit as being made as an OEM component for an equipment manufacturer. From what I found when doing a google search it appears to me that the 1286 unit was used on furnaces made by Armstrong. Based on what I found they look to be the same. However it is still good idea to compare the logic built into the control by comparing the information on the label of the one you got to this one. And do not assume the wire color code to be the same, so look at the schematic of the new one when installing. I have made that mistake before. As I said they appear to be the same. Also this control is often referred to as a cad cell relay because it allows the light sensing cad cell to shut of the burner when it sees a bad flame or no flame. If the appliance is dirty the relay button will pop. It will continue to shut the appliance off more frequently until it is cleaned. My point if the relay is shutting off the burner you should not assume it is broken as it more often than not is doing its job and letting you know there is a flame problem. To ignore this risks potential problems such as a blowback of soot into the house. It is a good idea to confirm the relay is actually broken before replacing.