Bill Anglin
07-19-2012, 10:56 PM
Back to back inspections where I got CO levels at the registers. I have never found this condition before and have a couple questions. The first furnace is a 80% Armstrong Air. The unit is only 2 years old. So I watched the flame pattern at the time that the blower turned on and the flame pattern changed. Before it was nearly solid blue. After there were flashes of yellow/orange. I took readings at the closest register and got 3 ppm CO. The second furnace is 41 year old Luxaire with draft hood. I got 3 ppm at the closest register as well. So here is my question. Is there any other condition besides a failed(hole) heat exchanger for CO to be detected at the registers? I know that 3 ppm is not a significant amount but this number should always be zero right? I also noticed regarding the 41 year old Luxaire that while taking a reading at the register, the temp of the register itself was 155 degrees. Seams to me that if water temp over 120 is a safety hazard, then a register at 155 would be also, My second question is regarding forced air temp, what is considered the normal operating temp at the registers and at what temp do you call it out as a safety hazard? Also just for my own knowledge, what is failing at the furnace to allow for 155 degree air? Thanks in advance for the help.