Why I Asked an HVAC Technician if My Parents' House Was Safe... What They Told Me Was Shock Me

I call my mother every Sunday at 5 PM. I have for twenty-two years. It's not an appointment — it's just what we do.

On the Sunday in question, she asked me about work, about my wife, about the kids. Then she said, in that offhand way people use when they're minimizing something, "I've been a little more tired than usual this winter. It's probably just the weather."

Eight words. "A little more tired than usual this winter." I almost moved past it. Everybody is a little more tired in January.

But then she said something else. She said, "Your father's been complaining about headaches when he wakes up. He's never had headaches before. We figure it's the change in barometric pressure."

Two people. Same house. Same new symptoms. Same winter.

I'm a commercial insurance broker. I spend my working life looking at risk patterns — the difference between a coincidence and a correlation. I hung up the phone that Sunday and I sat in my kitchen for a long time thinking about what my mother had just described without realizing she was describing it.

For three days I thought about calling her doctor. Then I thought about calling my father's cardiologist. Then I thought about making them an appointment with the neurologist my friend's wife had seen for her memory issues.

On Tuesday morning at 7:30 AM I did something different.

I called an HVAC technician.

I'll tell you why.

The house my parents live in was built in 1974. The furnace was replaced in 2009. The water heater is original to the house, which means it's fifty-one years old. There is an attached garage where my father still idles the car on cold mornings to warm it up. Every single source of carbon monoxide a home can have is present under their roof.

And I realized, sitting at my own kitchen table on Monday night, that in the thirty years I'd been visiting that house as an adult, I had never — not once — asked anyone whether the air my parents were breathing was actually safe.

I'd inspected their financial paperwork. I'd driven my mother to her dermatologist. I'd installed grab bars in the shower. I'd set up their Medicare Part D.

I had never asked whether the house itself was trying to hurt them.

Dave Morrison is 58. Third generation HVAC — his grandfather started the family business in 1952, his father ran it from 1978 to 2015, Dave runs it now. He services about 800 homes across three counties. He doesn't advertise. Everybody finds him by word of mouth.

I'd used Dave twice before — once when my parents' AC died in August of 2019, once for a routine furnace inspection in 2022. Both times he'd spent longer at the house than the job required. Both times he'd left my mother's kitchen with a cup of coffee and a story about his own parents.

I called him Tuesday at 7:30 AM. I told him what my mother had said on Sunday and what my father had been saying about the morning headaches. I asked him whether he could drive out and make sure the house was safe.

He was quiet for a second.

Then he said, "Michael, I've been waiting for someone to ask me that question for thirty years. Most people call me when something's already gone wrong. I'll be there Thursday morning at 9."

Thursday morning I drove the forty minutes to my parents' house and met him in the driveway. He'd brought two pieces of equipment with him — a combustion analyzer the size of a thermos, and a handheld carbon monoxide meter. He'd also brought a clipboard with a printed checklist.

He worked for two hours. He inspected the furnace. He pulled the cover on the water heater and ran a draft test. He went into the attached garage and asked my father how long he idled the car on cold mornings. He walked the house from basement to attic with the CO meter running, taking readings in every room.

Then he came back to the kitchen. My mother had made coffee. Dave accepted a cup, pulled out a chair, and sat down at my parents' table.

And he told us three things in the next fifteen minutes that I want every adult child of aging parents in America to know.

Because they shocked me. All three of them.

And Dave said, "Your parents don't know any of this. The reason they don't know is that nobody is supposed to tell them. The industry agreed thirty years ago that you weren't supposed to find out."

Dave pulled out a notebook. He'd clearly had this conversation before.

Thing #1 — The test button on your parents' CO alarm does not test whether it works.

He pointed up to the ceiling in the hallway where my parents' white plastic detector had been mounted since 2011. Fourteen years.

"Every few months your mother presses that button," Dave said. "She hears a chirp. She thinks it means the detector is working. It does not mean that."

He explained it plainly. The test button tests the speaker — it confirms the device can make a sound. It does not test whether the electrochemical sensor inside the device can still detect carbon monoxide. The sensor and the speaker are two completely different components, wired to two completely different circuits.

"I could hand you a detector with a sensor that's been dead for five years," he said, "and you'd press the test button and it would chirp, and you'd put it back on the ceiling, and you'd feel safer. That is the single biggest misconception in residential home safety."

My father, who is 77 and has pressed that test button probably two hundred times in the last fourteen years, stared at the table.

Thing #2 — The display on the detector is legally prohibited from showing low readings.

Dave said this is the one that surprises people the most.

Every residential carbon monoxide alarm sold in the United States is built to a standard called UL 2034. That standard, written in the 1990s, explicitly prohibits the device from displaying any carbon monoxide reading below 30 PPM.

Not because the sensor can't detect it. Because the industry decided you shouldn't be told about it.

"If the air in your mother's bedroom is running 22 PPM every night all winter long," Dave said, "the display is legally required to show her a zero. She looks up at the ceiling and sees green light, zero reading, everything's fine. Her sensor detected the 22. Her display isn't allowed to tell her."

He explained the reasoning. In the 1990s, utilities and fire departments had complained about "nuisance calls" from detectors triggering on low-level readings. The industry's fix wasn't to make the detectors smarter. It was to make them quieter. UL 2034 was rewritten to force alarms to ignore sub-30 PPM exposure and to require sirens to delay at 70 PPM for up to four hours before sounding.

Dave shrugged. "They optimized for fewer phone calls to the fire department. They did not optimize for a 74-year-old woman being told her air is safe when it isn't."

Thing #3 — The detector your parents have was chosen at the minimum spec by the builder.

Dave asked my father who installed the CO detector in the hallway.

"The builder, I think. When we replaced the furnace in 2009, the code inspector said we needed one. The guys who did the furnace installed it the same day."

Dave nodded. "That's how almost every CO detector in American homes got there. A code inspector showed up, the contractor pulled the cheapest UL-listed unit off the truck, screwed it into the ceiling in thirty seconds, and wrote down that the box was checked on the inspection form. Your parents have the $14 minimum-compliant model that a plumbing supply house sold to a contractor in bulk. It was designed to pass inspection, not to protect your mother."

He tapped the notebook. "And it expired in 2016. Its sensor stopped working nine years ago. The test button has been chirping the whole time."

My mother, who is 74 and trusts systems the way people of her generation trust systems, looked up at the ceiling. Then she looked at my father. Then she looked at Dave.

"So I haven't had a working CO detector in this house in nine years."

Dave said, "That's correct, ma'am. And you're not unusual. You're the majority."

That's when he told me what to do about it.

Dave said he'd started recommending a specific detector to his customers about a year and a half earlier.

Not a brand he was sponsored by. Not a referral partner. A plug-in 6-in-1 unit that one of his colleagues at a continuing education HVAC conference in Cleveland had showed him during a coffee break.

Try Shinova. A plug-in detector with a real-time digital display that shows the actual PPM number in the air — every reading, every second, no 30 PPM floor.

"The reason I recommend this one and not the ceiling units," Dave said, "is that it's the only consumer-grade detector I've tested that shows me the real number the way my professional analyzer does. Your mother can walk past it in the hallway and see whether the air is reading 3 or 18 or 24. She doesn't have to wait for a siren. She doesn't have to trust that the test button means anything. She sees the number. That's it."

Here's what Dave told me makes this specific detector different:

✓ Real-time digital display — Shows the actual PPM number in the air. If the sensor is reading 14, it shows 14. If it's reading 22, it shows 22. No 30 PPM floor hiding the low-level exposure that's been making my father's head hurt in the morning.

✓ Alarms starting at 25 PPM, not the 70 PPM ceiling unit threshold. The difference between catching exposure at its chronic low-level stage and waiting until the poisoning is a crisis.

✓ 6 threats in 1 device — Carbon monoxide, natural gas, propane, smoke, temperature, humidity. The detector on your parents' ceiling almost certainly watches one of those.

✓ Plug-in installation — No ladder. No drill. No electrician. No asking a 77-year-old man to climb up on a step stool. You plug it into the outlet next to your parents' bed in the time it takes to pour a cup of coffee.

✓ 24-hour battery backup — Keeps monitoring during power outages, which is exactly when portable generators get fired up and become the number-one source of residential CO deaths in America.

I ordered four Shinovas from my phone standing in my parents' driveway while Dave packed up his truck. One for their bedroom. One for the hallway outside. One for the living room where my father watches the news every evening. One for the finished basement where my mother does her crafts in the winter.

They arrived Thursday of the following week.

I drove the forty minutes back to my parents' house on Saturday morning. My father had already pulled the old ceiling detector off the wall and had it sitting on the kitchen counter. He handed it to me without saying anything.

Manufactured 2011. Expired 2016. Fourteen years of false assurance.

I plugged the first Shinova into the outlet next to my mother's side of the bed. The house was the way it always is on a January Saturday — furnace running, storm windows sealed, my father making coffee downstairs.

The display lit up.

27 PPM.

Not lethal. Not even enough to trigger the old ceiling alarm that had been giving my parents a green light for nine years past its own expiration date. But exactly the level Dave had predicted we'd find — enough to make a 74-year-old woman "a little more tired than usual this winter" and enough to make a 77-year-old man wake up with headaches he was attributing to barometric pressure.

I called Dave from their kitchen.

Dave was at the house by 9 AM Monday. He'd brought the combustion analyzer and a specialized CO meter his father had handed down to him in 2015.

The furnace checked out fine. Heat exchanger intact. Flue pipe seated correctly. Combustion efficiency within spec.

Then he tested the water heater.

My parents' water heater was installed in 1978. Forty-seven years ago. I grew up bathing in hot water that came out of it. Dave ran a draft test on the flue — the pipe that's supposed to carry combustion gases from the water heater up through the roof.

He walked back into the kitchen holding the handheld meter and said, "Your water heater is back-drafting. When the furnace cycles on, the pressure change in the basement is pulling exhaust gases back down through the water heater flue and into the house instead of up and out the chimney. It happens maybe twenty times a day. Each time it happens, a small amount of CO enters the basement air. Over eight hours overnight, in a sealed-up house in January, that's your 27 PPM reading in your mother's bedroom."

He condemned the water heater on the spot. My parents had a new one — a sealed-combustion direct-vent unit, the kind that can't back-draft — installed by Thursday.

I plugged the remaining three Shinovas over the weekend. By the following Monday morning all four were reading zero.

It's been seven weeks since that Sunday phone call.

My mother told me last Sunday that she's been sleeping better than she has in two years. She said she'd been chalking the fatigue up to getting older. She said, "I'd actually convinced myself this was what 74 felt like."

My father hasn't had a morning headache since the second week after Dave's visit. He told me on our last phone call that he'd "forgotten what it felt like to wake up with a clear head." His words.

The old ceiling detector, the one that had been hanging in the hallway since 2011 and had stopped working in 2016, is on their kitchen counter. My father won't throw it out. He says he wants his grandchildren to see it.

"That thing gave me a green light for fourteen years," he said. "Nine of those years it was already dead. I want the kids to understand that just because something looks like it's working doesn't mean it is."

Once I started telling this story, other people started telling it back to me. At work. At my son's basketball game. At the gym. Every single adult child of aging parents I know has some version of this:

"My mother said on a Sunday phone call that she'd been forgetting names more than usual. I spent a month researching memory care facilities. My brother-in-law — who builds houses for a living — asked whether her furnace had been inspected. I called his HVAC guy. Her bedroom was reading 23 PPM from a cracked vent. We fixed it for $320. She's fine. We cancelled the neurologist appointment."

— Thomas R., Pittsburgh PA

"My father is 79. He lives alone since my mother passed. He'd been telling me he was 'just tired all the time.' I drove up to visit for Thanksgiving and I realized I didn't know how old his CO detector was. I ordered three Shinovas before I left his house. His kitchen was reading 19 PPM from a back-drafting boiler. The plumber fixed it in ninety minutes. Three weeks later my father was walking around his yard raking leaves like a man ten years younger."

— Lisa K., Madison WI

"I'd been having a recurring argument with my sister about whether our mother was 'declining' or whether something was actually wrong. I called my HVAC tech instead of calling another doctor. He told me the same thing Dave told Michael — test button tests the speaker, display is prohibited from showing under 30 PPM, builder units expire silently. I ordered three Shinovas the same day. Her bedroom was reading 21 PPM. She is not declining. She was being poisoned. Slowly. For years."

— Robert A., Hartford CT