The Furnace Thread

[Edward]

Yeah, it's the one code installers seem to know all too well.

I think it's in the code book for the concrete floors to slope away from the floor drains also. It must be because in all my years of doing this trade, I've seen maybe two water heaters that leaked...right into the floor drain. It usually goes through the wall to ruin the carpet in the other room.

 

[Edward]

The fan is below. The external air filter is a 16 by 24 by 1 that easily slides out of the slot for cleaning/replacement..

The furnace guy talked to my family, who relayed the message to me. Maybe the message got mixed up somehow. The next time I call the furnace guy to tune up the furnace/AC unit I should probably be there myself to ask questions. I've taken the door off, and peered into the unit before, but could not find an internal filter. However, I don't want to disassemble it in winter to peer inside. I don't have that much confidence in my HVAC skills. Maybe in the spring, when its not so critical that the unit stay on-line constantly.

Thank you Edward.

Yeah, there's no internal filter inside of it. It may have a rack inside the blower cabinet for one, but since they put on one the outside for easy access, the inside rack is not used. Even it being a 90% furnace...I never heard of another filter being needed for anything. An EAC may have a pre filter, but it isn't that hard to get to.

 

[Blake]

My furnace is actually about to go out really soon. The fan motor is making a lot of noise when it's ready to stop running, it had stopped entirely but I had to remove it, clean it and lube it up real good... it cut back on and has been working for 3 or 4 days now but I know it wasn't a permanent solution. Still ain't sounding right. Edward should I replace the motor or the entire furnace? I sure appreciate your insight brother.

 

[Edward]

My furnace is actually about to go out really soon. The fan motor is making a lot of noise when it's ready to stop running, it had stopped entirely but I had to remove it, clean it and lube it up real good... it cut back on and has been working for 3 or 4 days now but I know it wasn't a permanent solution. Still ain't sounding right. Edward should I replace the motor or the entire furnace? I sure appreciate your insight brother.

The motor can be replaced for a lot cheaper than the furnace. It'll come with a 1 year warranty on the motor. I don't know how old the unit is...If it's 15-20 years old, you might want to bite the bullet and change it. Added efficiency, a new motor with a longer warranty...The new units warranty would probably cover the new motor for 5 or 10 years instead of one. That'd be a judgment decision on your part to change it or not.

Don't go bottom of the line if a new one...OTOH...don't go top of the line either. No matter how good a salesman can make it sound.

 

[Michael74]

Annual cleaning of the blower wheel and housing is recommended for maximum air output, and this must be performed only by a qualified servicer or service agency.

I wonder if this is what the furnace guy was trying to tell us?

http://www.franksheating.com/webapp/GetFile?fid={C515C9A8-F227-4501-B246-F0E3E7C8612B}

 

[Edward]

I wonder if this is what the furnace guy was trying to tell us?

http://www.franksheating.com/webapp/GetFile?fid={C515C9A8-F227-4501-B246-F0E3E7C8612B}

I seriously doubt it. Cleaning the squirrel cage is sort of a standard thing to do. Recommending that a qualified servicer does it is also pretty standard because there is a shock hazard. It's 120 volts, and not only that, but a lot of motors have a capacitor hooked up to it that will continue to hold 370 volts even after the power is switched off to the unit. Not everyone knows this! So it's fairly easy to get knocked on your butt if you don't realize this and take precautions. Capacitors can be discharged safely so that one won't have to worry about getting shocked. All you do to discharge a capacitor is to remove one wire from it (either side) and short the two terminals together with an insulated screwdriver or some implement. You may get a teeny spark but not usually. Then it's safe to handle or test the micro-farads.

If the unit had any sort of new type, or specialized filter that was designed into the unit, for that specific application/unit, then you can bet money that it's mentioned in the book/paperwork. That would be a pretty big departure away from what is considered as a standard/typical component furnished furnace unit. They do this sometimes here and there (especially Lennox, bah!) for various purposes, but they make it obvious, especially something that would have to be routinely serviced or cleaned.

(Page 7 of Manual.)
"2. BLOWERS – The blower size and speed determine the
air volume delivered by the furnace. The blower motor
bearings are factory lubricated and under normal
operating conditions usually do not require servicing.
Annual cleaning of the blower wheel and housing is
recommended for maximum air output, and this must be
performed only by a qualified servicer or service agency./"

This is where it would be. Nothing about a secondary or specialized filter on the unit. I'm not saying the guy lied to you, more likely, it was a miscommunication. This is easy in the trade because so few people have a grasp on how the equipment operates, or the terminology associated with it. Much less specialized features of a specific unit.

Over time, I have realized that a lot of people are...scared of their furnace...(not necessarily you), "I wouldn't want it to blow up!" is one that I hear quite often. This shouldn't be so. Your furnace is your friend. The better you know your friend, the less intimidation there is. It takes massive amounts of gas in just the right mixture to explode. The ratio that one needs of NG (Natural Gas) in the air for an explosion is 5 to 15% by volume of the room. This is a lot of gas. They never really say it on the news, because it adds insult to injury, but 99% of the explosions that you hear about, the people were doing something stupid and not exercising common sense. So...respect you furnace, but don't be terrified of it.

 

[Michael74]

Yes, the more we know the better.

So we should call the furnace guy annually to clean the fan, check the charge on the A/C, etc.... In between, we should change/clean the filter whenever it gets dirty. A decent filter may keep the fan cleaner in between visits too, enhancing its efficiency.

Also, never mess with internal components, unless you know how to make it safe. (I would have no idea where to find the capacitor without blueprints for the unit.)

 

[Edward]

Yep. Dirt restricts air flow, On the blower wheel, it'll cut down the CFM, Inside the burners it restricts the airflow into the burner and this throws off the gas/air mixture, then it will not burn efficiently which could affect the ΔT. So it's a good idea to service or have serviced your furnace every year. I differ with the book info on their recommendation on how to clean the burners. Dry brushes or rags and a vacuum never get all the dust. The burners need water ran through them and a damp cloth should be used on most parts of the furnace. In this way, it gets clean and not just the big hunks, lol.

The good companies will pull the burners and wash them. I do. Dirt on the computer board acts like a sponge and absorbs moisture, sometimes creating unwanted electrical paths and burnout of the board. We use those cans of compressed air or electrical contacts cleaner in a can to clean the boards. At least brush it off with a dry paintbrush.

There's a lot of hack companies out there that do very little when they service a unit. Lots of times they essentially just, change the filter and check it for gas leaks, but there's so much more to it. It's easy to test the safeties on the unit, and to get amp draw readings of the load devices on it. The ignitor and flame sensor on it can be ohm'd and a determination of how much service life is left in the device. If your service man doesn't have his electrical meter in his hand with him when he comes to service your unit...redflag. This is why you see such huge differences in prices for servicing furnaces. Sure, you can get it done for 40 bucks, but they wont do much to it. The people who charge more for the service know it takes time to do all these things to the unit, and really do everything to it.

 

[Edward]

If you live in a dry area of the country, you may want to consider a Humidifier. This may trim down your gas bill just a little also. Moist air holds the heat longer than dry air does. It's a more comfortable heat also, which may discourage turning up the thermostat so much. Humidity is otherwise good for a home also. It will protect your woodwork and wood furniture and lessen cracking from dryness.

Typical comfortable humidity levels are about 30-40% indoors.

 

[Michael74]

I'm near a lake. The air is usually pretty humid. Thanks Edward. I understand a bit more now.

 

[Jethro Bodine]

...a lot of motors have a capacitor hooked up to it that will continue to hold 370 volts even after the power is switched off to the unit. Not everyone knows this! So it's fairly easy to get knocked on your butt if you don't realize this and take precautions.

Yeah, great little items to keep around the office, hee hee hee hee.

Nothing funnier than tasing someone at the water cooler.