I have a Carrier 394GAW000075 Gas Heater I'm trying to troubleshoot. I replaced the 3-wire intermittent pilot assembly (LH680005, reused the ignitor portion) last season but, I've had issues with the gas pilot catching consistently. I call for heat, the ignitor is clicking with spark but the pilot either doesn't ignite or takes along time to catch. The frequency of catching is getting lower & lower. If I light manually, the pilot lights instantly and the heater moves thru it's cycle and main burners fire and heat to set temp.

Looking for suggestions. Ignitor gap issue? Intensity of spark issue? Pilot gas volume too low?

 

Welcome to the forums.

Natural gas or propane ?
What does the pilot look like when it lights ?
It should be fairly large and bushy.

The replacement ass'y you installed may have had an undersized orifice requiring more gas.

 

Thanks for the response. This is a Natural Gas furnace. When the pilot is lit it is large. It's split by the deflector and reach down to the bi-metal sensor and reaches upward a good 1 1/2" -2". As mentioned, the unit cycles fine once the pilot lights.