Everything you didnt want to know about gas hot air furnances... and HVAC Quicksand

rayinpenn

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Thirty years ago your average gas fired hot air furnace was a relatively simple affair. When the thermostat called for heat it ignited and the fire heated the heat exchanger and the blower came on a sending hot air through your ductwork and bam your house gets warm. But they weren’t particularly efficient in pulling every BTU for every bit of gas burnt.

12 years ago along comes Ray with an inefficient undersized A/C and boiler units. In the summer the upstairs, where the bedrooms are, would always be warmer. My A/C and boiler unit were about 20 years old at the time. I pulled the trigger on a $12k and change for new highly efficient boiler and bigger A/C unit.

The new unit was a direct vent model which meant in addition to a multi speed blower fan it had a smaller exhaust fan that blew all that nasty CO2 out a vent that the installers cut into the side of my house. Did you know the one byproducts of burning gas was H2O - yes water. So my furnace also has a little reservoir with a pump to evacuate the water. Compared to the original furnace this thing is a nuclear reactor. Oh and one other thing since the nuclear reactor will no longer be using the chimney and the hot water heater will not supply sufficient heat to dry out the chimney we need to replace the brand new water heater for a power vent model that also vents out the side of the house $1,200. Yep quicksand.

12 years later I discover, after the much touted polar vortex, the multi speed 10 year warranty fan in the furnace has died. In addition to some electronics Bam. $2,000 plus the exhaust fan is 12 years old and doesn’t sound good. Keep in mind my Yotul gas stoves are heating the house. I had the furnace only come on to heat up the house in the mornings. No one likes to shower in a 58 degree bathroom- at least no one I know. So tomorrow, at great expense, the old 2nd furnace in this house will be replaced with the latest generation of Nuclear Reactors. Being positive person I’ll call the new unit 3 Mile Island.

There are times when complexity and efficiency come at a cost of durability. It is a painful lesson but I cant help but wonder what could I have done differently? As I sit here boilerless and look at the fire in the Yotul, that had its moment in the sun too, I thank God at least we have heat. At least for today.
 
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Did your utility bills go down after installing the high efficiency units 20 years ago?

My experience has been that you're better off in the long run with the simplest mechanically and electronically configured units you can get, even if you do give up a small amount of efficiency.
 
Did your utility bills go down after installing the high efficiency units 20 years ago?

My experience has been that you're better off in the long run with the simplest mechanically and electronically configured units you can get, even if you do give up a small amount of efficiency.

I generally agree about simple being better. But my relatively new furnace last month produced a bill about the size of a payment on a Cadillac.

There's a compromise, and there's a break even point.
 
<b>freedomatlast: “Did your utility bills go down after installing the high efficiency units 20 years ago?”
</b>

The bill are indeed low for a house this size but we also added
1. The Yotul Stoves
2. Triple Pane Windows
3. A layer of blown in insulation in the attic
4. Storm doors
5. Insulated well fitting garage doors
 
I have heater/ exhaust / light combo fixtures in my bathrooms, can go from 58 to 80 in a few minutes.

Shop ebay or google for hvac parts, should be able to find them at reasonable cost if you are a diy kinda person, get a few more years out of the current system
 
Ray, I feel your pain.. I'll spare you my details, because they mirror your own so closely. It reminds me of the Ethanol boondoggle. 10% ethanol, would mean a a 10% reduction in price of gas IFF the production of ethanol were free, and IFF ethanol did not cause stuff to breakdown and fail way more frequently than ethanol-free gas does. Since neither of those things are true, the 10% savings actually costs us a bundle.

Same deal with these HE appliances. When I went through the new HE furnace debacle, in addition to the extra costs of maintenance, and early replacement, the thing really did not heat as comfortably as my old inefficient unit. It was noisier, draftier, and dirtier than the unit it replaced. I'm sure the unit did not save me 10% of what I spent on maintenance and earlier than I anticipated replacement.

As my dear old uncle used to say..."screwed again"...
 
And there is the law of diminishing returns.

When I moved into this house in 1992, it had the old style 1986 furnace, I'd estimate maybe 55% efficiency? I was doing a remodel, and needed to move it. The A/C was working, and we don't use A/C that much here (hot spells last a week or two a few times a year - but when you need it you need it - hot and humid). So I decided to replace the furnace but keep the A/C.

The 1992 replacement furnace was higher efficiency ~ 83% (?), but still used a standard chimney (they added a liner to reduce the diameter to increase the draft from heat rise and reduce condensation). The main difference was a draft inducer fan to pull those flames like a jet engine through the heat exchanger.

Two years ago, the A/C went out, so I decided to replace everything - the now 24 YO furnace still working, but probably near EOL.

The catch was, I really wanted comfort for the A/C - it's tough to get them sized right to keep the humidity down during a warm spell, and also keep the house cool on the hottest days (which also seemed to coincide with us having a big group of people over). So I went for the 2-stage compressor, and variable speed fan (which has worked very well). But that only comes with the higher efficiency (96% ?), PVC vent furnace. Some comparison:

Instead of efficiency, it is more useful to look at fuel consumption - consider that a 100% efficient furnace would consume 100 units of fuel, then an 83% furnace would consume 120 units of fuel to provide the same heat, and a 55% furnace would consume 180 units.


100% - 100 units fuel

55% - 180 units fuel

83% - 120 units fuel
96% - 104 units fuel

So you see you can save 60 units going from 55% to 83%, but save only 16 units going from 83% to 96%. Almost no savings left above 96%.

I agree, for many of us, the extra cost/complexity just is not worth the upfront cost, and likely higher maint/repair costs.

-ERD50

 
Thank you rayinpenn...

Our plan for keeping the gas furnace going during the deep deep freeze, was prayer.

So far, so good. the furnace and A/C is now as old as the house... built in 1999. So far, so good. aside from a few $100 bills along the way, never a problem. For the past 10 days, 73 degrees 24/7.

That said, my next door neighbor (house built at the same time) has been talked into three... YES THREE, complete new systems.

Sooo.... we'll fix... not replace, if and when the time comes.
 
Next door to my apartment in Pittsburgh is a house with one of them super high efficiency gas furnace. With the recent two days of -4 or so temps. I observed stalagmites and stalagtites at the vent. They had to come out with a hair dryer to melt the ice out of the ehaust pipe, while trying not to melt the plastic pipe. The stalagmite was about 2' tall.


Seems to me a lower efficiency unit with less gizmos is less expensive, even in the long run.


I had my oil furnace replaced last spring. I opted for the less efficient and less complicatd unit. Talking with the owner of the HVAC shop, he said he makes a lot of money on and the service calls on the super high efficieny units. Too many things to fail.
 
I'm seriously thinking of heating my place with several plug-in oil-filled radiators. I'd take the electric hit each winter, but I'd save at least $5,000 on having a new heat pump installed, plus the maintenance cost. I'm pretty sure the maintenance cost is zero on an oil-filled radiator. Another idea is the old classic electric baseboard heat. Hmmm. Gotta be a way to beat the system, lol. Just a matter of how much electricity these alternatives would use. edit to add: I just read an article which said heating with electric baseboard consumes 2.2 times the electricity as using a heat pump. Not too bad. My current winter (heat pump) electric bill is only $140 per month at the worst. Hmmmm. Something to think about.
 
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Our gas furnace quit in mid-October. Think it is probably something to do with pre-venting the burner area prior to ignition or maybe the ignitor. Last year whacking the exhaust fan motor and lubing it got it cranking during the time we were there. This is a furnace we installed new back in 1999 or so - we were real space efficient and wedged it into the underfloor area, then installed the tiled kitchen floor over it. It is not coming out in one piece. At 50 it wasn't a big deal to skinny on my belly like a reptile over to the furnace - 20 years later I'm much less enthused.

We/me addressed the issue with armloads of firewood for a couple weeks and going south for the winter. We had planned to stay at the Oregon house for a couple days in January, but it would have taken too long to bring the heat up and dry the place out. This summer I'll let the furnace people get an early start on the job if I can overcome my DIY/thrift bent.
 
We replaced our gas furnace a few years ago. Old one was still working, but 28 years old and just not efficient. Plus we added a new gas hot water heater. Both are high efficiency and our gas bill went down, close to $30 per month.
At the time, they tried to also talk us into replacing our AC unit, as it is a bit small for our house. But, we only use it a few weeks a year. that is on hold for now.
 
I'm seriously thinking of heating my place with several plug-in oil-filled radiators. I'd take the electric hit each winter, but I'd save at least $5,000 on having a new heat pump installed, plus the maintenance cost. I'm pretty sure the maintenance cost is zero on an oil-filled radiator. Another idea is the old classic electric baseboard heat. Hmmm. Gotta be a way to beat the system, lol. Just a matter of how much electricity these alternatives would use.

Tenants who go with oil filled heater use in preference to the baseboard heat we provide often seem to require having their wall outlet receptacles replaced. Probably a function of older outlets not having really good connection to the plug from the heater. Something to consider - changing the receptacle preemptively.
 
Tenants who go with oil filled heater use in preference to the baseboard heat we provide often seem to require having their wall outlet receptacles replaced. Probably a function of older outlets not having really good connection to the plug from the heater. Something to consider - changing the receptacle preemptively.

Interesting. Thank you for that. My DeLonghi oil-filled radiator plugs right into the 1986 receptacles normally. Haven't noticed anything unusual. If I may ask, do your tenants prefer using the oil-filled radiators because they use less electricity than the electric baseboard heat?
 
Electric baseboard heating is a pain since you can't have anything touching it or even very close to it. So walls suddenly become off limits to a lot of furniture. Better to get the smaller electric fan forced units. They take up a lot less linear space and and circulate the air better.
 
IMG_0323.jpgLets just say the good news never ends... My fancy programmable thermostat
 
Most of those thermostats can be powered from the thermostat wires that supply 24V AC. I think the catch is (going from memory) that you need a "C" (Common?) connection, and they don't always run that.

-ERD50
 
Installation is easy but this time I am having them do so then it is all covered under the warranty. Its official I hate all things heating.
 
That house is possessed by demons. I would consider moving! Like to a lower COL area with a much better climate.
 
Interesting. Thank you for that. My DeLonghi oil-filled radiator plugs right into the 1986 receptacles normally. Haven't noticed anything unusual. If I may ask, do your tenants prefer using the oil-filled radiators because they use less electricity than the electric baseboard heat?

Think it is cost related - usually a single tenant, which means localized heat right by the place they are watching tv or at their computer is adequate. On the receptacles, if it is really easy to insert the plug the connection probably isn't great - and things go from not great to bad to arcing at the plug quickly. A new receptacle is stiff and it can be difficult to insert the plug; lots of spring tension gripping the plug tangs = great connection.
 
View attachment 30722Lets just say the good news never ends... My fancy programmable thermostat

I hate alkaline batteries. I have a bunch of them but I’m moving to high end rechargeables. As I run through the alkaline, I check them frequently for leakage, a pain. I also remove them from things I don’t use often. I’ve had them leak on so many things. I know it’s not a perfect solution, but all I can do is clean them up by brushing off the crystallized acid with an old toothbrush and hope for the best. Try to get your receiver to work without you original remote. Generally I don’t use it because the universal remote will turn it on. Hence the batteries sit and leak and ruin the remote. It does work for now, but the contacts are a mess.
 
Resurrecting this thread as woke up this morning and noted ......no heat. So called the repair shop. Have an 80% efficient gas that is almost 23 years old. Only service has been me replacing the fan motor run capacitor about 5 years ago.

Turns out a control module relay is bad. He could replace the control module for $406 (later found the part online for about $125). He hot wired the fan to be constantly on so we've got heat and a bit of time to decide. While checking it out, on one test the draft inducer fan would not come up to speed and squealed bad, but a little lube fixed (temporary??) fixed that issue. So I'm looking at $400 min. if the draft inducer fan bites the dust in near future, it'll be another $700 min.
So leaning to replace furnace and debating how high tech to go. Better efficiency and complexity or replace with like kind?
House was built in 1963 current unit installed in 1996 along with AC. We have no plans to move so may be here another 20 years.
Starting to get quotes.

Oh....northern PA, it was 7 degrees this morn but now up to 30 and sunny. And have two ventless log sets as backup heat.
 
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While the new heaters are more efficient, 93% or more is common, I think you will have even bigger potential savings with the A/C side. I bet your old system is able to be replaced with one at least 50% higher efficiency. If you live in an area where you use lot of A/C it may be a good time to upgrade the whole system.
 
So leaning to replace furnace and debating how high tech to go. Better efficiency and complexity or replace with like kind?
House was built in 1963 current unit installed in 1996 along with AC.

You probably couldn't buy one like your '96 model if you wanted since the government mandates efficiency, which means lower energy costs but often at a higher initial cost.
 
Also check with your utilities for rebates. If above a certain efficiency, you qualify, so the upgrade may be almost free.
 
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