Fuel oil burner running intermittently

furnaceheatingoilthermostat

Fuel oil (Beckett oil burner) here. It's -20°F outside right now and the house is at 61°F even though I have the thermostat cranked up to 75°F (we have a thermometer in the house as well, that's how I know the temp).

The burner kicks on about every 3 – 4 minutes, runs for a few minutes and shuts off. I'm trying to determine if this sounds problematic or if its expected behavior. And, of course, if its problematic, what the troubleshooting process should look like.

My understanding is that: if the house temp is below the thermostat temp, the burner should be running nonstop/continuously until the house temp comes up to the thermostat temp. Yes/no?!

If this is normal expected behavior, I'm wondering: why? That is, why isn't the burner running continuously until the house comes up to the right temp?!

And if this is not normal/proper behavior, what are some of the reasons for what could be going on here?

Best Answer

Is this in a boiler (steam or hot water heat)? Are you getting any heat in the house?

Assuming yes and yes, this can be normal operation. In a boiler, the burner heats water to a set temperature (e.g. 160F). When that temperature is reached, the burner shuts off. To actually deliver heat into your home, there is usually a circulator pump. This takes the hot water in the boiler and moves it through your radiators, which release some of the heat from the water into your home and send cooler water back to the boiler.

If your heating system can't keep up with demand, it can be because the boiler can't make enough heat, or because the radiation can't distribute it quickly enough. It sounds like your limiting factor is the radiation, which is not unusual. So even though your heat is constantly on, it is being distributed as quickly as your system can currently manage, and that is slower than the burner can produce heat. So the burner gets to take breaks.

A few options to address this:

  • Confirm that all radiators are hot; if some aren't, they may have their valves closed or be air-locked and need to be bled. Steam radiators may have defective air vents.
  • Increase your boiler's water temperature (probably not higher than 180F, though the design max temperature depends on your particular system and may be higher or lower than that)
  • Check that your circulator pump is working properly. Some have multiple speed settings, so you can try increasing that to increase water flow through your radiators.
  • Add radiators.