Is my furnace supposed to blow out cold air?

Question

We had a new furnace installed last month. Natural gas, forced air. Now that it's really getting cold outside it is impossible to keep the house comfortable. The thermostat (which is the same old one, not replaced) says 70 degrees but it's so cold in our house. The air blowing out of the vents is actually cold, not hot the way it was with the old furnace. The burner is on because I can hear it and the vent pipe is extremely hot. My husband says it is supposed to be this way, he says it is more efficient. How is it efficient to blow cold air into a room? Are new furnaces like this?

Please answer, I'm freezing.

The vent pipe is galvanized metal. It is very, very hot. Almost can't touch it. But again, the air coming into the rooms is cold, feels like air conditioning.

My husband finally recalibrated the old thermostat and that seemed to help. The air blows out for a longer period now and heats up a bit. It's still not hot air but much warmer than it was. We are going to buy a new thermosat this weekend. Thanks for all your answers. That's what finally got my husband to realize that something was wrong.

Answer 1

Your heater may be short cycling. The T-Stat anticipator may not be set correctly,causing short cycles and warm to cool air.Also,the fan blower speed could be too high.Low or medium for heating is the speed preffered.

Answer 2

First of all, if the vent pipe is metal, they didn't put in a high efficiency furnace. Also, if they didn't replace the thermostat at the same time, you got ripped off. The air coming out of a properly functioning gas furnace should be around 120-130 degrees. It does not matter if it is high efficiency or not. I would guess that the people who put it in didn't even do a load calculation. In short, it probably is not properly installed.For more info, check out the furnace page at my source.

Answer 3

I would be willing to bet that the heat anticipator setting on the old thermostat does not match the new gas valve. You are getting what we in the business call droop. Get the guy out there and make him install it right. You have something hooked up wrong because I have abrand new forced draft air heating system from Amana in my old house and I gotta tell you that air comes out quite warm. and it only takes a short while for that heater to heat up this house.My heater does this: I first can hear the draft inducer motor come on and then I hear the heat come on like a whosh and in about 25 seconds nice warm air comes out in every room. You need to get them back out there. Something is wrong.

Answer 4

Call back the installer. They have installed a faulty furnace or installed it improperly. If it is a modern high-efficiency furnace the vent pipe is probably a PVC pipe and should NOT be more than very warm. Certainly not "extremely hot".

Bert

Answer 5

Sounds like the low limit was never set properly for the fan. Increase the low to 130 and high to 150. This will stop the fan from blowing cold air.
This is the probe in the supply plenum above the burner.

Answer 6

We just moved in to our newly built home and had the same issue with our downstairs unit. It came on but blew out only cold air. We had the installers back and they had just forgotten to throw a switch on the unit in the basement. This may or may not be your particular fix so it would be wise to call the installers and check it out.

Answer 7

It depends on what cycle the furnace is in. I'd call your repair person immediately. If your a do it yourselfer, you may want to call your furnace manufacturer for their help.