When swings point to a fault: sensor, fan or igniter

Most swings come from pellets, weather, the lid or dirt. A few come from a part that's worn, damaged or failing. The skill is knowing which you're looking at, and when to stop and call the maker.

Start with what's normal

Your own manual has the range. For one maker, a typical day in good weather means no more than 15°F of swing either way.¹ Another maker's range is wider, so don't borrow a number from a different brand. The page on why temperatures swing lists the ranges that makers give.

A pellet maker gives an example of what isn't normal: a 250°F setting that sees the display sink to 200°F, then rise as high as 325°F.²

Rule out the easy causes first

The same pellet maker says people usually assume a mechanical issue. It says the real cause is very often far simpler.² Before blaming a part, check what's covered elsewhere on this site:

• Weather: see cold, wind and rain.
• Lid habits: see what a lid check costs.
• Dirt: see how ash changes heat.
• Fuel: see pellet quality and feeding.

Clear those, and any swing that remains is more likely to involve a part.

The sensor

The sensor, often called an RTD, is the probe that passes the chamber temperature to the control board.³ The controller trusts it completely. A pellet maker warns that a probe left uncleaned can get dirty and make the grill's temperatures fluctuate.³

So a dirty probe is a first suspect, and cleaning it per the manual is the first step. If it's clean and the display still disagrees wildly with a second thermometer, follow your manual or contact the maker. How the loop works is on the page about the controller and sensor.

The fan

The fan forces air across the fire pot and gives the pellets oxygen. It also circulates heat and smoke around the cooking chamber.⁴ The sources on this site don't list fan fault symptoms. If you think the fan isn't working, read your manual or contact the maker.

The igniter

At startup an ignition rod heats the pellets while the fan pushes air across the pot. Once the pellets are burning, the rod shuts off.⁴ So the igniter matters most at the start. If the grill won't light, follow your manual or contact the maker.

Don't reach into the pot or test the igniter with household tools. It's an electrical part near fuel. Follow the manual's steps.

Damaged baffle or drip tray

One maker says that if the drip tray or heat baffle is damaged or placed incorrectly, you may see temperature issues.¹ That's a part you can inspect by eye once the grill is cool. For damaged parts, the maker says to get in touch with Customer Service.¹

When to contact support

Contact the maker when:

• Swings stay far outside your manual's range after you've ruled out the easy causes.
• The grill won't light, or the fire keeps going out.
• A part looks damaged, warped through or rusted through.
• The display and a second thermometer disagree badly, even with a clean probe.
• The manual tells you to.

Have the model number, what you've already checked and what you saw on the display. Check your warranty terms in the manual.

Never open the control box, change wiring or modify parts yourself. This site doesn't cover repairs. The manual and the maker do.