Heater problem

clemsonfan39

Need some help. Noticed kids room a bit cooler than usual, I usually raise thermostat at night. I have small children. Anyway, the problem. I went to thermostat (digital) and raised temp..............nothing. Switch from AUTO to FAN. The blower works, but blows cool air. And there is a noticeable odor, NOT GAS. More like a overheat smell. It is a less than 10 year old unit and is a York Diamond 90, and heat is natural gas. I even turned off power supply and gas line and turned all back on and still same issue. Is there something in the heating mechanism that can "burn out". I am sure this is something that I need a tech to come to fix. Just curious what it could be. Thanks

Steve Whitbeck

smell

I would say that the draft inducer is stuck. There might be something in it or the drain line might be plugged and it is full of water.

Jean-David Beyer

draft inducer?

I have two 125,000 BTU/hr Rheem gas furnaces at my Quaker Meeting. I have had one draft inducer fail after at least 10 years of service. It did not totally fail, but the bearings were screaming, so I had it replaced -- after the former contractor oiled the bearings and said it would be OK. Since the bearings are "permanently lubricated", they cannot be oiled, and I said so, but he said this always worked. So the next week, I got a different tech out to replace the inducer. It comes as a unit, so the motor cannot be replaced separately.



(The other furnace's inducer made a serious squeek when the former contractor was doing the annual maintenance this fall, so I asked him to replace it. He had a "universal" inducer, but it would not fit. He would be back "next week" with an appropriate new one. A month later he had still not come, we switched to a new contractor.)



But if it seized up, there is a draft-proving switch (detects vacuum; probably calibrated) that would prevent the furnace from firing. In that case there would be no heat at all. So if the furnace is firing, my guess (as a not professional) is that it is not the draft inducer. For that to be the case, both the draft inducer must be running too slowly or not at all, and the draft-proving switch would have to be stuck ON.  If both the draft inducer and the draft proving switch failed ON fror my furnaces, it would be one hell of a mess with fire all over the inside of the furnace where it chould not be. And the fire might not even stay just in the box. It would be just awful.



Come to think of it, if the controller is smart, it checks that the draft proving switch is OFF first, then turns on the inducer and waits for it to go ON before starting the ignitor and makes sure the current through the ignitor is correct before opening the gas valve. Maybe it does all that; I hope. I know there is about a minute pre-purge before it turns on the fire after the thermostat asks for heat.



We had a problem of no heat from some of the registers. Our problem turned out to be the original installer. There were two main ducts with elephant trunk hoses to the various registers. These were just pushed on to the register boxes. After a time, some of them fell off. This kept the ground hogs in the crawl space warm, but did not heat the building. The ducting was stupid and uninsulated, so we had it replaced with a more intelligent layout of insulated main ducts. The elephant trunk hoses were mostly short and uninsulated, but fastened with one screw at each end, so they should not fall off.

clemsonfan39

Problem solved

Capacitor needed replacing! All good, thanks