Upon arrival inspected unit and found dirty burners clogging and not establishing flame on all 4 burners. Informed homeowner of issue and likelihood of problem reoccurring without repair measures, homeowner was interested in upgrading burners to stainless steel to prevent future problems pertaining establishing flame. Replaced 4 burners with stainless steel burners and test run furnace. Cleaned flame sensor as well while things were apart, and sealed every hole on furnace burner cabinet to prevent dust from homeowners woodworking shop in furnace room from damaging components internally. No issues as of now. Filter merv rating is higher than usual - I would recommend no higher than merv 10 but it is fully optional