Hi there. Kind of a screwy deal here. I'll try to be as detailed, yet as brief as possible. 7 days ago, I had a new furnace installed in my house. The old one was from 1958 and the motor locked up. Gas fired units. The new one is a Gibson model# KG7SA 126C 45D. Approximately 1200 square feet of space. The new unit is cycling several times before the thermostat shutoff temperature is reached. Not just burners, but the whole system. Inducer fan comes on, burner lights, blower comes on, burner goes off and blower throttles back, blower goes off when the unit has cooled. This is followed by an IMMEDIATE restart of the whole process. The contractor that installed it said it was because some of my vents were partially closed and the filter was dirty. Opened them all fully, and put in a new filter - no change. It goes through about 4 cycles of this every time to raise the house temperature 2 degrees. I have a digital thermostat, and don't think there is an anticipator on it - Ritetemp 8022C. Cold air return trunk at the furnace is 8x24. Warm air trunk lines are two 8x12s. This isn't normal operation for a new unit is it? Is this something that will damage the new furnace, and how quickly? I'm tired of dealing with these guys, and would like to be armed with information the next time I talk with them. A friend of mine mentioned adjusting the high limit setting. Could this solve the problem? Sorry for all the questions - I'm reaching for a solution here. Let me know what other info you need, and I'll get it to you asap. I'm a pretty handy guy, with the exception of HVAC stuff, but with an explanation, I'll do what I can. Appreciate the input.

I have a sewer type odor around my furnace (I have posted about this before). Ive had 2 plumbers and 1 HVAC tech come out to determine if this is propane or sewer gas. It has been determined that there is no propane leak. We thought we had the problem solved when we cleaned a trap into which the condensate line drained. But the problem has returned. Today I removed the above floor trap (it was cut in to a 3" stack next to my furnace with a 2" tap. I removed it and capped off the 2" portion of the wye. I then ran new drain lines from the furnace condesate trap to a floor drain, everything has plenty of fall and the water runs out the pipe when the furnace runs. Here's my questions - how does the furnace condensate "trap" stop gases from entering the drain pipe? The tap is a small white box about 2"x4" by 1/2" . Has 3 lines into the top. 2 appear to be water drain lines the other some kind of small line maybe determining if the trap is full before the gas valve is opened? A flexible drain line comes from the front of this trap about 1 1/2" from the bottom and the goes on into my new drain line. Is there tubes in this trap that form a p trap? How does it stop the gases from entering the drain line and then into my basement? If I add another regular p trap in my new line will that have any negative effect on the operation of the furnace (I'm worried about the line which goes to the gas valve switch from the furnace trap. Please help as I've had this odor problem on and off for over 2 years.