We live on a ‘power island’. This was the 3rd outage in 9 months. But in almost 40 years it’s never gone out for 24 hours. 50 years ago, 1973-74 winter, there was a 3-day outage. This looked similarly dangerous. We live next door to a cattle pasture, so when our power goes, no heat, no water but we still have natural gas flowing.
Often, our power island goes down in isolation, so the trucks come quickly and not a big deal. We conserve water and keep the freezer closed and power is usually restored in 12 hours or much less.
We reported our outage at 5:15pm, Friday Jan 12th. It had been snowing hard all day. I went out with the tractor/snow blower and then the lights went out. I actually rode my motorcycle to the office on Monday, so we were expecting another easy winter. Four days later, we’ve gotten 24” of snow and sub-zero highs. Funny how life can change in a day or so.
We bundled up for the night knowing that we needed to keep an eye on things – did not sleep well. When we first reported, there were only a few thousand outages so we were still very hopeful.
By morning, 80,000 homes were without power. We dug out with help from a great neighbor (with a bigger tractor) and went out for breakfast. Checking again,the outages went up to 92,000 of the 1.1 million homes, almost 10% of southeastern Wisconsin. In our county, the hardest hit there were 42,000 which was more like 20% and totalled more than even Milwaukee. Our optimism for a fast restoration faded.
Checking the temperature with a digital meat probe (who has an indoor thermometer handy?), the house was already down into the 50’s. We estimated we were dropping at about ¾ a degree per hour. In 24 hours it would be below 32F and the water pipes would start to freeze and possibly burst. We have never tried draining all the water in our house so I called our plumber and asked questions. Did we need to drain all the water or just the pipes? – just pipes. He wasn’t sure how many gallons – no one does this for year-round houses. He said we could put antifreeze in the toilets rather than scooping them out. (You can tell this was getting real…)
We considered getting a generator in the past, but our water pump needed double 20 amp breakers. Friends had looked into a setup that big and got a $12,000 estimate. At the time, we didn’t think it was justified by an occasional inconvenience – almost always in the summer. But back in 1973, I came home from UW and was greeted by a 15” blizzard. I remember our family getting out sleeping bags and stoking up a roaring fire to keep the house from freezing for three cold days.
3 or 4 months ago, youtube recommended a video on running your furnace on a car battery. I’m pretty sure I didn’t watch it, but I did remember the title. After breakfast we went to my office to watch at least a half dozen videos on alternate power and wiring a typical home furnace. I even took notes – white to white, black to black and a jumper wire to bypass the thermostat. This idea was born out of the great Texas Deepfreeze of Feb 2021. I grabbed a spare computer power cord and we headed home.
I had never heard of this possible solution – or anyone else trying it. To say I was skeptical is a huge understatement. Could it be as simple as it sounded on youtube? I do a lot of DIY from youtube and have successfully fixed dishwashers, clothes dryers, wash machines and even, yes, a couple minor furnace problems (on the coldest nights of the year). But a 10 minute video to fix my motorcycle ignition switch was a 2 hour project 2 weeks ago (so its always harder than it looks). When the situation you face has a huge downside – burst pipes in 24 hours – game theory suggests willingness to try unorthodox options. What could possibly go wrong? (right, wrecking our furnace and trying to get a new one over a holiday weekend)
Down in the basement, I confirmed that our furnace was on a 15 amp breaker – so no huge power draw, check. I carried a small somewhat old battery from the shed (not much power but easy to carry). Connected it and nothing happened, dead. I took the 20 year old DC-AC inverter out to the garage and plugged it into the lighter socket. The little rusty box groaned to life with a squeaky whir. To test the output, I got a variable hand mixer from the kitchen. The blender came to life but died when I got to the highest setting. There was a sharp whistle and the green light turned red on the 300 watt power supply. Not very powerful.
Undaunted, I ran an old 100’ extension cord down to the basement, plugged in an electric sander and it ran. I flipped the furnace circuit breaker – just in case the power came back on while playing in the wiring. Next I combined my little electrical know-how plus the videos on white and black and surveyed all the wires. There were two obvious wire nuts from where I replaced the exhaust fan. I splayed the PC power cord and connected the loose ends there. Put a jumper wire on little red & white thermostat wires and plugged it in. The exhaust motor whirred to life – I was so excited. Next the gas should turn on and light… but after a few minutes, only the fan was kept running.
At this point I should add a disclaimer, THIS IS NOT A HOW-TO ARTICLE ABOUT FURNACE HACKS. This article is to explain the observation, hypothesis, testing methodology and thought process in a very real crisis. Furnace maintenance and repair should be done by certified professionals, since there are serious issues at stake. However, in the last furnace crisis – below-zero Christmas Eve a few years ago, the repairman who did actually come to help, looked at the relic and said, “I don’t know anything about fixing one like this.”
For all these reasons, I felt it was worth trying to wire in the alternative power. My test revealed that I’d powered on part but not all the furnace. I decided to open the on-off switch on the outside of the furnace and try again – further upstream as it were. Re-wired, I plugged it in and flipped the switch. Again the fan started but this time after 60 seconds or so, the gas valve clicked and the flames came to life. WOW! Miraculous!
But when the blower that usually pushes the heated air out into the house kicked in, everything died. I needed more power. I headed to the True-Value.
“Do you have any inverters?” I asked the first clerk I met (an old guy – they usually know, or so I thought).
We checked in a few electrical sections, eventually finding some in an unlikely spot. They had one that was about double what I was testing, 750 watts, 1500 peak. It was their last high-powered one, worth a try. $120 so I kept the receipt.
Almost all the Youtubers said a car battery alone would do, so I connected it and switched it on. The on/off furnace switch wiring came in handy because turn on the car and the power and then trudge downstairs and watch what happened. Again the blower started, again flames and again death on the blower. But this time it tried harder to start the fan, maybe it actually ran briefly. My wife suggested starting the car for more power and trying once more.
We didn’t want to run the car in the garage. Even with the door open, that would cost precious heat, so I backed it out and we adjusted the extension cord; just long enough. There was only one video with the car running. They said you could close the hood to be inconspicuous. I moved the inverter to a low spot, clicked it on and tried again down at the furnace. After a brief prayer, I flipped the furnace switch. The blower started, it kept on running! We had heat again! But after 20 minutes, it all stopped. The car was still running. The red power light was blinking and the inverter was beeping. I put my hand on it and it was hot. Not a great idea to put it on top of the warm engine and close the hood, the thing has heat fins for cooling – probably important. I moved it to the fender and we waited a half hour till it cooled down.
With the hood open and repeated temperature checks, the power supply stayed ice cold (it was now down to about 15F outside. The system ran for 3 hours and got us back to normal, then suddenly shut off. Checking the furnace, it was very hot. Perhaps there was a temperature safety switch built in? Would this hack really get us through the below zero night?
Our gas grill is connected to the natural gas, so we had just finished a lovely candle-light dinner. We were toasting to our success. We let the furnace cool again for almost an hour, and started it up. Repeatability is huge in testing. It ran for 45 minutes then shut off again…
We showered at a friend’s house and got some more time to think. Great to take a break in the midst of a crisis (if at all possible).
“Maybe it’s the thermostat?” my wife suggested.
“I don’t think so because its one of those fancy wifi ones. Without power or the internet I can’t imagine the thermostat could still work.”
Though everything was now running – for a while – it was still possible I’d hooked up the jumper incorrectly. There are lots of wires – many of them relate to AC and not to heating. Now that we were back home I decided to try another bold move. While it was running again, I pulled off the jumper wire. That was really hard since I’m obviously an “if it ain’t broke, don’t break it” guy. It continued running without pause. Going upstairs to the thermostat, I pointed the flashlight and numbers were visible.
Turns out that when the furnace has power, it also powers the thermostat. My wife had rightly observed that both shut-downs happened at about the same temperature (still using the meat probe). At our normal setting – coincidence? Probably not. We ran up to that same warmth, at about 11 pm, shut down and went to bed. We had learned so much with our trial and errors that we figured I could restart it in the morning, go to Church and then heat the house back up even in the below-zero weather.
Sleeping lightly and checking the meat probe, I got up at 5am, started the car and went back to bed. The house had dropped to near 60F. We were losing more than a degree/hour (but not much more). We were also heating slower with -4F outside. The Electric Company sent an email saying we should expect to be out for another 24 hours, mid-Monday. They suggested serious precautions for houses and moving to warmer quarters. We were now melting snow to refill the toilets and our optimism was a bit higher.
Church was a bit sparse but we stayed for coffee hour and a nice lunch. Few could believe what we had been through so far or that it might be an entire day more. Of the dozen or so people I talked with, none had ever heard of this solution (partly why I’m sharing this).
We stopped to top off the fuel. The 8 hours or so of idling used about 3 gal of gas, so about $10 worth. My wife found an article about possible dangers of long idling. There were three: running down your battery, overheating your car and running out of gas. The first one wasn’t happening, I was using my LS430 V-8 with plenty of power. The 2nd was super unlikely at below zero. And we kept an eye on the last one. Again, not recommending this, your house, car and furnace will certainly be different, but in some situations you do what you can.
Now that the heat was working, we checked the freezers (generally best to keep them closed when power goes out but never went 2 full days before. Most things were still solid but a few things had started to thaw. We took the freezer items outside in big covered tubs. Very easy to keep frozen things frozen, we might have done this sooner but this wasn’t a priority while the whole house might freeze. Refrigerator items were put into insulated coolers in the garage (to keep them slightly warmer) imagine that. We discussed putting ice packs in the coolers and bringing them inside if we had to go longer. We also used the roof-rake to scrape off some of the 24” of snow. If the house were cold the roof wouldn’t melt but we were now starting to get icicles. Ice dams are also not to be trifled with.
As the sun set, another steak went on the grill, wind-chill was -24F but we grill year round. We now had ample wine from the Piggly Wiggly. As I tended the inferno, I noticed some flashing lights through the trees. Then more lights. Looking closely I saw the orange logo of the Electric company. For a while, 5 trucks were over there. A long wait with more prayers for everyone’s safety, ultimately more than 48 hours had elapsed (but 16 hours sooner than estimated). The lights burst on and we cheered! Today, I’m sitting in our cozy sun room looking out at the winter wonderland. How life can change in a day or two.
Conclusion – Observe, Measure, Hypothesis, Experiment, Explain
In the middle of the situation, I used my phone to post on linkedin. 15 comments, with many asking how we did it. While still fresh in our minds, I decided to write up most of the adventure.
In case you’re not in the cold North country I wanted to point out that this car + inverter + extension cord can also work in warm weather to keep a fridge running. We’re definitely going to keep that inverter, thank you Biebel’s True-Value!
With any innovation, there are similar steps. Often, ‘necessity is the mother of invention’.
THIS IS NOT A HOW-TO ARTICLE ABOUT FURNACE MODIFICATION. This is to recount the observation, hypothesis, testing methodology and thought process in a very real crisis. Furnace maintenance and repair should only be done by certified professionals, since there are serious issues at stake.
Here is the original youtube video that inspired me to attempt this
Feel free to comment and repost.