https://www.googlenestcommunity.com/t5/Nest-Thermostats/E448-Message/m-p/804108#M144512 <P>Is it a warm air furnace with a cooling coil?</P> Sat, 09 May 2026 14:12:37 GMT Edtheheatman 2026-05-09T14:12:37Z https://www.googlenestcommunity.com/t5/Nest-Thermostats/E448-Message/m-p/804092#M144510 <P>We have a new 4th Gen Nest Learning Thermostat which continues to show E448 no power error message. I cannot figure for the life of me why. I am replacing a Honeywell ProSeries Thermostat with basic wiring Y, W, R, C and G.</P> Sat, 09 May 2026 12:26:54 GMT https://www.googlenestcommunity.com/t5/Nest-Thermostats/E448-Message/m-p/804092#M144510 Rgarraton 2026-05-09T12:26:54Z https://www.googlenestcommunity.com/t5/Nest-Thermostats/E448-Message/m-p/804107#M144511 <P>Do you have zone valves?</P> Sat, 09 May 2026 14:09:34 GMT https://www.googlenestcommunity.com/t5/Nest-Thermostats/E448-Message/m-p/804107#M144511 Edtheheatman 2026-05-09T14:09:34Z https://www.googlenestcommunity.com/t5/Nest-Thermostats/E448-Message/m-p/804108#M144512 <P>Is it a warm air furnace with a cooling coil?</P> Sat, 09 May 2026 14:12:37 GMT https://www.googlenestcommunity.com/t5/Nest-Thermostats/E448-Message/m-p/804108#M144512 Edtheheatman 2026-05-09T14:12:37Z https://www.googlenestcommunity.com/t5/Nest-Thermostats/E448-Message/m-p/804174#M144513 <P>I am not sure. It's&nbsp; a gas heat unit and separate cooling</P> Sun, 10 May 2026 02:10:12 GMT https://www.googlenestcommunity.com/t5/Nest-Thermostats/E448-Message/m-p/804174#M144513 Rgarraton 2026-05-10T02:10:12Z