Nest thermostat - fan on but heat not coming on

[Eugenia618]

Installed a nest learning thermostat at mom’s house (haven’t turned on learning yet) followed same wiring pattern as older thermostat minus the jumper wire since directions noted not to use. Got heat immediately.  

Had shut down heat while away for a few days and turned on via nest app couple hours couple hours before arriving. House was was warming but not to set point noticed fan on but not heat.

Rechecked settings and wiring and ensured was on gas and force air got burner to come on but still find it runs fan and not igniting the burner consistently.  Not sure on next steps beyond potentially going back to original thermostat 

[Worzie]

Sounds like my issue this weekend!  I'd watch the process to see how long the burner stays lit.  If it's kicking off early, I would clean your flame probe with super fine grain sandpaper or replace it with a new one.  They will cake especially if you do laundry in the vacinity.

[zoeuvre]

Hi folks,

Thanks for chiming in, @Worzie. 

@Eugenia618, uh-oh! I'm sorry to hear that your heat won't turn on after installing a Nest Learning Thermostat. Are you located in North America or Europe? And could you share here the wiring photo of your previous thermostat and a photo of how you connected the wires to the Nest Learning Thermostat base so I can take a closer look? 

Keep us posted.

Best,

Zoe