[RumDiet]

My direct vent heating system is not working. I have an oil burner/forced air system with a Tjernlund direct vent - one of the leds is not lighting up at all - the furnace won't fire up until I hit the reset button - once that's done the furnace produces heat - once the house reaches temp and the system shuts down it won't turn back on.

Can anyone offer some advice? This is in upstate NY - I'm thinking I need a new control board, but don't want to jump too quick if its something simple.

Thanks all and Merry Christmas.

 

[roughneck]

Is the direct vent running? What's the reading on the cad cell when it's running vs when it's off? When was the last time it was cleaned? Nozzle, strainer, and filter new? Oil pressure/suction readings?
What LED are you talking about?

 

[throrope]

The only control board that failed on me had an obvious black burn where a component cooked. You operation is more charateristic of a sensor failure such as flame sensor or pressure switch, both of which I endured. The operation manual for your unit should have a trouble shooting chart that uses on board LEDs that flash or light to indicate condition. For me a pressure sensor on the backside of the blower went and recently a flame sensor. The pressure switch was $12 online. The flame sensor was a quick polish with steel wool. My unit is gas.

Another thought is your fuel oil filter. If clogged, you could be starving for fuel.

 

[RumDiet]

The direct vent and the furnace are both working - problem seems to be in the control panel - the LED #4 in the diagram is not lighting up and seems not to be telling the furnace that its OK to fire up. I have no idea what the CAD reading is or how to get one - just a humble DIYer with a cold house on the day before Christmas eve!

 

[RumDiet]

Thoro - no black burns - the manual gives error codes where one or another of the LEDs flashes to indicate an error. Problem here is that the LED is not lighting at all.

Fuel filter just changed and furnace working anyway.

 

[beenthere]

LED 4 is an error code light, if there is a problem with the venter . Your problem is with the burner/furnace.

 

[Colbyt]

In the documentation or attached to a movable panel there should be a flow chart that details the start up sequence. Follow the chart.

I'm just a DIY guy also but it sounds like a failed sensor of some kind aborting the boot sequence. If direct vent in this case means intake air also I would look at the sensor that starts the air flow into the unit.