Heating and cooling # HVAC fault codes, by control board A fault code identifies which safety circuit tripped, not how to fix it. These pages put the code in plain language, tell you whether it is a check you can safely make or a call for a technician, and cite the maker's service manual. Every control board differs — the same flash count means different things on different models — so start from your brand. ## Choose your equipment ### [Goodman modulating gas furnace](https://hvacbuddy.shop/error-codes/goodman-modulating-furnace/) GMVM97, GCVM97, AMVM97 11 codes, each with a safety verdict ### [Goodman single-stage gas furnace](https://hvacbuddy.shop/error-codes/goodman-single-stage-furnace/) GMS8, GDS8, GHS8, GMS80, GDS80, GHS80 9 codes, each with a safety verdict ### [Carrier two-stage induced-combustion gas furnace](https://hvacbuddy.shop/error-codes/carrier-two-stage-furnace/) 58DXT, 58UXT, WeatherMaker 8000 two-stage 14 codes, each with a safety verdict ### [Lennox furnace with a SureLight ignition control](https://hvacbuddy.shop/error-codes/lennox-surelight-furnace/) G61MP, G51MP, SLP98, EL296, ML195, SureLight / Basic SureLight boards 9 codes, each with a safety verdict ### [Rheem gas furnace with a 7-segment IFC display](https://hvacbuddy.shop/error-codes/rheem-ruud-7segment-furnace/) R801T, R802V, R801V, R92 / R95 series, Ruud Achiever equivalents 13 codes, each with a safety verdict This is a growing library. A page is added only once its code map can be traced to the manufacturer's published service manual — we do not reproduce tables from memory or from unverified sources. ## What these pages do not do They do not describe repairing a gas, combustion, refrigerant or control-board component. For most codes the correct repair is certified work, and the honest value we can add is telling you which cases those are, so you neither overpay nor put yourself at risk attempting one. We are not affiliated with any manufacturer and are not an official support channel. By [HVACBuddy Editorial Team](https://hvacbuddy.shop/authors/editorial-team/). Last reviewed: 2026-08-21. HVACBuddy publishes independent information. We do not install or service equipment, we do not dispatch contractors, and we do not sell leads. Nothing here is engineering, tax, or legal advice.