HVAC repair & diagnostics
I'm Thomas Darby, a licensed PA home-improvement contractor (HIC #PA2199962) with EPA 608 Universal certification, and I do furnace repair, boiler repair, and AC diagnostics in Lock Haven, Mill Hall, Avis, Loganton, Beech Creek, and Jersey Shore. I diagnose before I quote, because plenty of no-heat calls turn out to be a $40 part rather than a new system, and I'll tell you which one you're actually looking at. I work alone, so booked is booked — but you get a written quote within 48 hours, and you put money down only when you say go.
The no-heat call in Lock Haven, PA tends to look the same: it's the first genuinely cold night, the furnace is running but not blowing hot air, and somebody has already told you the whole unit is shot. Maybe it is. Often it's a flame sensor, a pressure switch, or a limit doing exactly what it was designed to do. I find out which before anybody starts talking about replacement.
I don't work on commission and there's no replacement quota over my head, because there's nobody above me to set one. That changes what I tell you. If your boiler needs a circulator and has another decade left in it, that's the recommendation you get, even though the replacement job would pay me better. If the heat exchanger is cracked, I'll say that too, and show you what I'm looking at rather than asking you to take my word for it.
Worth saying up front: I'm one person. There's no dispatch board here, and I won't promise you a truck at midnight, because I can't keep that promise. What I can promise is a straight answer about when I can get there, and EPA 608 Universal certification when I do.
What's included
- No-heat diagnostics on gas and oil furnaces
- Boiler service and circulator replacement
- Central A/C diagnostics and refrigerant work
- Mini-split and heat pump troubleshooting
- Flame sensor, igniter, and pressure switch replacement
- Blower motor and capacitor replacement
- Thermostat and control wiring faults
- Condensate drain and pump repairs
- Seasonal tune-ups and pre-winter checks
- Repair-or-replace assessments in writing
- Service areaLock Haven, Mill Hall, Avis, Loganton, Beech Creek, and Jersey Shore
- QuotesDiagnosis first, then a written repair or replacement number inside 48 hours. Nothing due up front.
- LicensingPA HIC #PA2199962
- CertificationEPA 608 Universal
- Warranty1-year workmanship
How the job runs
- You tell me what it's actually doing and when it started — no heat, blowing cold, short cycling, tripping the breaker, banging on startup. Half the diagnosis is in the story.
- I work the system in order: thermostat call, power and safeties, ignition sequence, fuel side, then airflow. Measured with instruments, not guessed at from the model number.
- I tell you what failed, what it takes to fix it, and what I'd do if it were my own house. Repair or replace is your call, and you make it knowing what I know.
- If it's a repair I can make on the spot, I make it while I'm there. Anything that has to be ordered, you hear the real wait time up front instead of finding out about it later.
- If replacement is the honest answer, you get a written quote within 48 hours. Deposit only when you say go, and no discount that expires if you think about it overnight.
- Work I do is backed by a 1-year workmanship warranty. If something I touched quits, call me back.
Real jobs like this
Common questions
My furnace is running but not blowing hot air. What's usually wrong?
On a gas furnace that's most often the flame sensor, dirty burners, or a limit switch shutting the burners down while the blower keeps turning. It can also be a clogged filter choking airflow until the unit overheats and trips itself off. Those are cheap fixes. It can also be a cracked heat exchanger, which is not. I check before I tell you which one you have.
Should I repair or replace my furnace?
That depends on what failed, not on the age printed on the label. A control board or an inducer motor on an otherwise sound furnace is worth fixing. A cracked heat exchanger, a rusted-through boiler section, or a system that has failed three different ways in two winters is throwing good money after bad. I'll walk you through what I found, then put the replacement number in writing within 48 hours if you want it.
Do you come out to Mill Hall or Jersey Shore, or only Lock Haven?
I work Lock Haven, Mill Hall, Avis, Loganton, Beech Creek, and Jersey Shore, plus the surrounding central-PA area. A run out to Mill Hall or the far end of Clinton County is a normal drive, not a special trip. If you're farther out than that list, ask anyway. I'd rather tell you no than have you sit waiting on someone who was never coming.
You're one guy. What happens if you're booked when my heat goes out?
Then I'm booked, and I'll say so instead of stringing you along. I don't advertise 24/7 service because I can't staff it and I won't sell you a promise I can't keep. What you get instead is that the person who answers is the person doing the work, and your job never gets handed to a tech who has never seen it.
Are you licensed to work on the refrigerant side?
Yes. I hold EPA 608 Universal certification, which covers refrigerant handling on any equipment type, and PA HIC license #PA2199962 for the home-improvement side. That matters on a repair call, because guessing at a refrigerant problem instead of measuring it is how a system ends up overcharged, and an overcharged system fails again in a way that costs far more than the original fault did.
Can you work on a mini-split or heat pump, not just a furnace?
Yes. I installed a Mitsubishi MSZ-FS18NA in Lock Haven, an 18,000 BTU single-zone hyper-heat unit rated 21 SEER2 that keeps making heat down to -13°F. On that job I pressure-tested with dry nitrogen, pulled a deep vacuum below 500 microns, and ran a standing decay test before charging. Troubleshooting one is the same discipline: charge, flares, condensate, control wiring, electrical, before anybody blames the compressor.