About a week ago , I had someone to come in and replace my old RA116 stack switch with a Honeywell R8184G oil primary , for the first day it was fine, next thing I know the furnace turned off and didn't come back on until I pressed the reset, it then runs for a short period of time before it turns off again and the only way to start up back up is to press reset again. I should probably also mention that when it does run the fan turns on too early and stays on too long any help would be greatly appreciated
New primary control switch problems
furnacehvacoil
Related Solutions
A heat pump thermostat prefers to operate the heat pump under "usual" conditions as that is expected to be less expensive. It will invoke the back up (or "emergency heat") when any of several conditions occur:
- The current indoor temperature is more than 4 °F/2 °C cooler than the temperature setpoint. This is the blockhead approach taken by primitive thermostats and intelligent thermostats when "anticipator mode" is disabled.
- The outdoor temperature is cold enough that the heatpump can not operate inexpensively.
- The "emergency heat" switch is enabled on the thermostat.
Some (advanced) thermostats might have an adjustable delta temperature value, but it does not look like the TH8320 does. According to the installer manual (see page 17), there is a deadband adjustment, option 0310. Besides directly controlling the deadband, it might also be used as the temperature delta or half of it. Try adjusting the deadband, save it, and then adjust the setpoint temperature above the current reading (which will drift up as your hot hand and body will warm the thermostat) and see if the delta is affected.
Something similar happened to my gas boiler. It was a problem with the ignition electronics. Every night, when the thermostat was lowered, the circuit board would cool down and a solder connection would come loose. Sometimes the board could be wiggled to make the connection again. Eventually I opened it up and identified and fixed the loose solder connection.
The ignitor box looked something like this:
Best Answer
Your old stack switch reacted strictly to heat. If the burner was producing heat within a certain period of time after the call for heat the stack switch allowed the burner to continue to run. The job of these items is to make sure that the burner does not continue to blow unburnt fuel into the chamber without a fire present. The 8184, on the other hand works in conjunction with a cad cell (light sensor) to insure a fire is present in the chamber preventing unspent fuel from being blown into the chamber. One of the characteristics of fuel oil burning under highly efficient conditions is that it produces a very bright yellow flame. Cad cell technology works particularly well with this type of light, it reacts to these light characteristics. Here is the rub. If the 8184 does not see the kind of flame it wants to see within a much shorter period of time is will shut down the burner and go into lock-out mode, requiring a manual reset to restart the burner. So if the burner is not burning as efficiently as it should it will not produce the color of light needed to cause the cad cell to react. A good bet is that your need a nozzle replacement. Another possibility is the fuel pump. Both of these items are critical to produce that fine fuel film that generates the highly efficient burn needed to cause the cad cell to react in the allowed time. The nozzle disperses the fuel into tiny droplets (we call it atomizing)into the chamber for burning. These nozzles become plugged with dirty fuel. They, as a consequence cannot produce the bright flame necessary to cause the cad cell to react. Additionally, the fuel pump could be the problem. As it ages it cannot produce the pressure necessary to atomize the fuel. Additional factors are involved but hopefully this points you in the right direction. A good tech can diagnose and repair this issue in a jiffy. Good Luck. PCL.