Any furnace concerns in extreme cold?

[Samsung4321]

I was in a house in Canada, when the night temp went down to -49 F.
Fun fact: -40C = -40F

That was lower than my car antifreeze, so I plugged the car in all night in the garage, and prayed the engine wouldn't crack. It was fine in the morning

= -40 * 1.8 + 32 = 40

Engine oil heaters.

Why not make it easy to drain, capture and reuse engine coolant?
Place receptacle, open filler cap, open drain tap?
To reuse coolant, engine must be warmer than coolant freezing temperature?
A freezing temperature engine could be run without coolant to warm it up first.
Very cold oil would be more viscous than grease?

 

[W2R]

Like most of the country, we're experiencing very cold and windy conditions. This is causing my furnace to run almost nonstop. Is there anything I should be concerned about with it running so much? Should I turn the temp down and let it "rest" from time to time throughout the day? From what I understand about a furnace about the only moving part is the fan motor and I can't imagine that needs a rest. But, I thought I'd ask in case I'm missing something. FWIW, I'm set at 72. I can certainly tolerate lower, but I'm very adverse to cold and prefer the warmer temp setting.

Even with a thick comforter on my lap at all times, the thermostat for my HVAC has been set on 74 the past couple of days. It's natural gas, which helps keep the bills down, but still I think the next bill is going to be quite high.

As for the effect of this on my heater, Here's why I'm not too worried:

1. First, I had the twice-a-year checkup done in October and was told that (at that time) it was functioning perfectly. The HVAC had been "short cycling" before then, but the HVAC guy cleaned it out and blew out the water which somehow fixed it.

2. Second, old people die of cold all the time and I am determined that that's not going to be me! I just changed the furnace filter. Also, like most people I'd rather buy an entire new HVAC system if/when I need one and stay reasonably warm, than die. And,

3. Third, it is cycling off periodically and then coming back on, as it should.

I'd suggest having your HVAC man come out and do the usual periodic cleaning and maintenance. But then, I suppose that this week is probably his busiest week of the year.

 

[rk911]

...However, oil, natural gas, etc, you need to be sure your heat exchanger is in good shape. If so I think you'd be okay with non stop operation. Of course a bad heat exchanger is bad even for short term use.

which is one reason why we have our furnace inspected every year before heating season. i recommend this practice to everyone.

 

[COcheesehead]

I would turn the dehumidifier on in case there is some condensation that could cause the furnace to rust.

And now for an opposite opinion….

We have a humidifier attached to the furnace. It keeps the house soft, static free and comfy.

 

[Which Roger]

Wow - some must like it hot! DW and I are comfortable with 66 during the day and 60 at night.

 

[aaronc879]

Wow - some must like it hot! DW and I are comfortable with 66 during the day and 60 at night.

Do you keep it cooler in the Summer or do you have a wide range of comfort zone? I use a lot more heat than AC.

 

[rk911]

If anything we turn it up. Well, not really but it's sometimes a temptation. We're also on natural gas forced air heat and no worries.

The worst it ever got was in our old house near D.C. during a cold spell. We saw -5°F which was about unheard of for that location. The furnace would run for an hour, shut off for five minutes, then run for another hour. And yes, I knew if the furnace quit we'd be draining the pipes and making hotel reservations. But that didn't happen.

our home has small duct work and only one register in most rooms so we keep an electric space heater in the living room, dining room, office and bedroom to augment the forced air furnace but also, along with the wood burning fireplace, as a Plan B should the furnace fail.

 

[rk911]

Do you keep it cooler in the Summer or do you have a wide range of comfort zone? I use a lot more heat than AC.

same with us. it can get hot and sticky here but we generally keep the AC off until the dew point climbs to 66.

 

[RobbieB]

I don't see any problem with continuous operation either. I worry more about the AC in the summertime.

 

[naggz]

I suggest keeping an eye on the flue exhaust in certain circumstances...

High efficiency furnaces sometimes vent out the side wall (not up through the roof), and exhaust moisture can condense and freeze below the outlet, creating a sort of reverse icicle (or stalagmite). If it gets too big, it can block the air inlet and/or the flue outlet (they are usually next to each other). Easy to see and break if it happens. But even in Canada with our long and cold winters, it's pretty rare to get that bad.

(Same potential issue with power vented gas water heaters that vent out the side)

And as others mentioned, change the furnace filter every 2-3 months. But just get the cheap ones. The furnace filter is meant to protect the fan, not filter the air. The ones with a high MERV rating are harder on the furnace fan.

 

[COcheesehead]

I suggest keeping an eye on the flue exhaust in certain circumstances...

High efficiency furnaces sometimes vent out the side wall (not up through the roof), and exhaust moisture can condense and freeze below the outlet, creating a sort of reverse icicle (or stalagmite). If it gets too big, it can block the air inlet and/or the flue outlet (they are usually next to each other). Easy to see and break if it happens. But even in Canada with our long and cold winters, it's pretty rare to get that bad.

(Same potential issue with power vented gas water heaters that vent out the side)

And as others mentioned, change the furnace filter every 2-3 months. But just get the cheap ones. The furnace filter is meant to protect the fan, not filter the air. The ones with a high MERV rating are harder on the furnace fan.

Modern furnaces are engineered to use MERV filters.

 

[Sunset]

= -40 * 1.8 + 32 = 40

.....

You forgot the (-) sign, so the answer is negative.

= -40 * 1.8 + 32 = -40

 

[frayne]

Don't have to worry about over taxing the furnace as the rolling blackouts give it rest every now and then. Usually two or three per day, thirty-forty minute duration. Eight degrees again this morning in TVA country.

 

[RetMD21]

It's a plot by the furnace and A/C manufacturers, they divided up the year so they don't step on each other's toes for breakdown repair costs

That explains it!

 

[old medic]

Propane furnace in a camper...running about all night... stops for about 10 minutes then runs for 30....

 

[freedomatlast]

I know many of you find comfort in the yearly HVAC inspections. I guess the idea is that these will somehow prevent breakdowns. But no one can tell when a control board is going to fail, or when a blower motor is going to make it's last revolution, when a capacitor is going to fail or a pressure switch diaphragm will tear. These aren't items that are replaced as preventive maintenance so I'm not sure how these yearly inspections would prevent such breakdowns. However, if this gives folks some peace of mind, then I guess their money is well spent.

 

[Healthy Lifestyle]

Modern furnaces are engineered to use MERV filters.

Learning much from these comments and will pay even more attention in hopes that my heating system continues to perform properly.
Also it is a good reminder to check the exhaust on the side of my house for any ice build up.

 

[Qs Laptop]

I know many of you find comfort in the yearly HVAC inspections. I guess the idea is that these will somehow prevent breakdowns. But no one can tell when a control board is going to fail, or when a blower motor is going to make it's last revolution, when a capacitor is going to fail or a pressure switch diaphragm will tear. These aren't items that are replaced as preventive maintenance so I'm not sure how these yearly inspections would prevent such breakdowns. However, if this gives folks some peace of mind, then I guess their money is well spent.

I agree with this. Someone correct me if I'm wrong but about the only preventative thing that a yearly inspection will catch is carbonized ignitor rods and/or flame sensors. Typically the tech will remove the rod(s), clean them and reinstall them.

Otherwise, as freedomatlast says, there is no way to predict the failures of major components.

 

[Qs Laptop]

My son called me in a panic on Wednesday evening complaining that this rental townhouse carbon monoxide sensors were activated and blaring.

Naturally, this happens during a blizzard. Minus 10 degrees outside with 6 inches of snow already on the ground and 20-30 mph winds. Windows were cracked and furnace shut down.

He called the gas company--they do arrive quickly. They sent a tech and the CO sensors confirmed there was CO in the house. About 50 ppm in the main floor and about 10-15 ppm coming out of ductwork vents in the upstairs bedrooms. Furnace was shutdown and several space heaters placed in strategic locations to keep pipes from freezing. He stayed at our place Wednesday and Thursday night.

A furnace company came out Thursday and determined the heat exchanger on the furnace was cracked. Furnace is a 16 year old Bryant cheapo model. Miraculously, the landlord reacted quickly (for once) and opted to have a new furnace installed (another shocker). This was completed yesterday afternoon.

So, you never know when your furnace might have a major malfunction.

 

[Sunset]

I know many of you find comfort in the yearly HVAC inspections. I guess the idea is that these will somehow prevent breakdowns. But no one can tell when a control board is going to fail, or when a blower motor is going to make it's last revolution, when a capacitor is going to fail or a pressure switch diaphragm will tear. These aren't items that are replaced as preventive maintenance so I'm not sure how these yearly inspections would prevent such breakdowns. However, if this gives folks some peace of mind, then I guess their money is well spent.

Some companies do guarantee the furnace will not fail for 6 months, so if it stops working they will come out for free. No idea if a part needs replacing, I'm sure they would charge for it and their charges quoted to me were about 8x what the part cost on Amazon.

 

[Sunset]

My son called me in a panic on Wednesday evening complaining that this rental townhouse carbon monoxide sensors were activated and blaring.

Naturally, this happens during a blizzard. Minus 10 degrees outside with 6 inches of snow already on the ground and 20-30 mph winds. Windows were cracked and furnace shut down.

He called the gas company--they do arrive quickly. They sent a tech and the CO sensors confirmed there was CO in the house. About 50 ppm in the main floor and about 10-15 ppm coming out of ductwork vents in the upstairs bedrooms. Furnace was shutdown and several space heaters placed in strategic locations to keep pipes from freezing. He stayed at our place Wednesday and Thursday night.

A furnace company came out Thursday and determined the heat exchanger on the furnace was cracked. Furnace is a 16 year old Bryant cheapo model. Miraculously, the landlord reacted quickly (for once) and opted to have a new furnace installed (another shocker). This was completed yesterday afternoon.

So, you never know when your furnace might have a major malfunction.

Close call.

I think with a cracked heat exchanger, replacement is really the only option, especially on a furnace that old..

 

[Walt34]

I think with a cracked heat exchanger, replacement is really the only option, especially on a furnace that old..

Way back in the '70's when I worked on heating/A/C stuff the cost of a replacement heat exchanger with labor was about 70 or 80% of the cost of a new furnace installed, so unless it was under warranty heat exchangers were never replaced.

 

[m3bs]

Living in the sunny south we have a heat pump that struggles when the temps get much below freezing, so the heat strips were spinning my meter last night when it got down to 11 degrees. I got nervous when I realized that the “new” unit that I had installed was in 1997. Time flies…..

 

[rk911]

I know many of you find comfort in the yearly HVAC inspections. I guess the idea is that these will somehow prevent breakdowns. But no one can tell when a control board is going to fail, or when a blower motor is going to make it's last revolution, when a capacitor is going to fail or a pressure switch diaphragm will tear. These aren't items that are replaced as preventive maintenance so I'm not sure how these yearly inspections would prevent such breakdowns. However, if this gives folks some peace of mind, then I guess their money is well spent.

of course our annual PM can't prevent all mechanical failures but a yearly inspection can detect issues that may develop into large problems. we were fortunate that one annual PM revealed a leak in the heat exchanger which if undiscovered could have resulted in a significant CO leak. that led to our replacing the furnace.

 

[m3bs]

Well, I guess I jinxed myself with the post about my heat pump yesterday. It quit today. Probably going to be tough to get it fixed this week. I suspect it my be the 24V control power transformer since I have no power to the thermostat. Breakers and fuses are all good. I had just told my wife I planned to replace it this spring….. Luckily it’s only supposed to get down to 23 tonight.