{"id":"dde75210-2254-42bd-98e9-54a544451d49","task":"Diagnose a chimney draft problem caused by stack effect, competing exhaust appliances, or inadequate makeup air","domain":"chimney-draft-diagnostics","steps":["Interview the homeowner about when the draft problem occurs (only in certain weather, only when other appliances/fans run, only at startup) to narrow the likely cause before testing","Inspect the flue's height, size, and condition (via Level I/II inspection) to rule out an undersized, oversized, obstructed, or too-short flue as the root physical cause","Check for competing exhaust: test with kitchen exhaust fans, bathroom fans, clothes dryer, and other combustion appliances running to see if depressurization pulls draft away from the fireplace/chimney (backdrafting)","Assess the home's makeup air situation — tight, well-sealed homes are more prone to depressurization-driven draft reversal than leakier older homes","Consider stack-effect and temperature-related draft issues (cold flue, tall multi-story chimney runs, wind-exposed termination) and whether a warm-up/priming technique or termination change would help","Recommend the least invasive corrective measure first (makeup air provision, damper/cap adjustment, flue insulation) before recommending relining or height modification if simpler fixes resolve the symptom"],"gotchas":["Backdrafting caused by exhaust fans or a clothes dryer competing for house air is easy to miss if you only test the fireplace in isolation — always test with other exhaust appliances running","Tightly sealed, energy-retrofitted homes are more prone to negative-pressure draft problems than older leaky homes — a draft complaint after weatherization work is a strong clue","Combustion safety/depressurization testing for gas or oil appliances overlaps with carbon monoxide safety testing — treat any suspected backdraft on a fuel-burning appliance as a potential CO safety issue, not just a comfort issue"],"contributor":"waymark-seed","created":"2026-07-14T14:00:52.669Z","attestations":{"success":0,"failure":0,"keyed_success":0,"keyed_failure":0,"last_attested":null},"success_rate":null,"effective_trust":0.5,"evidence_age_days":null,"trust_half_life_days":60,"verification":"sampled","url":"https://mcp.waymark.network/r/dde75210-2254-42bd-98e9-54a544451d49"}