NOAA's Johnstown/Cambria figures
For reference, one station: NOAA's engineering weather data lists Johnstown/Cambria, about 6 miles east of the city. In an average year at Johnstown/Cambria, NOAA counts about 69 hours with the wet-bulb temperature above 73°F and about 684 hours above 67°F. For the same station it lists a 50-year basic wind speed of 90 mph (3-second gust at 33 feet), a 100-year rainfall rate of 2.6 inches per hour and about 53 freeze-thaw cycles in an average year.
How the list is arranged
This checklist runs through the year in five stretches, from the thaw to midwinter, followed by notes for storms, warning signs and record keeping. Lines marked Technician need someone with gauges, a meter or a combustion analyzer; everything else is owner work. Before you open a cabinet or reach into the outdoor unit, set the thermostat to off and kill the power at the furnace switch and the outdoor disconnect.
Through any running month
- Slide the filter out and hold it to the light. When light barely passes, put in a new one and note the date on a strip of tape.
- Walk the house and make sure no supply register is shut and no return grille sits behind a couch or a bed skirt.
- Listen as the system starts. A new knock, whine or hum is worth writing down with the date.
- Run a hand along the base of the furnace or air handler now and then; dampness or rust streaks are worth a call.
The thaw
- Once the snow pulls back from the outdoor unit, clear away sticks, leaves and anything that wintered against it.
- With power off at the disconnect, run a gentle stream from a garden hose down through the coil fins. Keep a pressure washer well away.
- Look for a pad that has heaved or tipped, and for foam insulation on the larger copper line that has cracked or gone missing.
- Trace the condensate line to where it ends and clear anything that has blocked it.
- Technician: a spring visit for refrigerant readings recorded on the ticket, the capacitor and contactor, and a look at the indoor coil.
Early summer
- Switch to cooling on a mild day, before the first hot spell, and feel the air at a few registers after it has run a while.
- A condensate pump earns a quick test: tip a cup of water into its reservoir and see that it empties.
- Prune shrubs and tall grass back to the spacing the outdoor unit's manual calls for.
- Change the thermostat schedule to suit the cooling months.
High summer
- Make note of any room that stays warm into the evening.
- Shine a flashlight into the drain pan beneath the indoor coil; it should not be holding water.
- Aim mower clippings away from the outdoor unit so they don't mat on the fins.
- Ice on the copper lines or the indoor coil means cooling should stop: set the system to fan, then phone for service.
First frost
- Try the heat on a cool day ahead of real need. A faint burnt-dust odor for a few minutes can be normal; a scorched-plastic or electrical odor is a reason to turn it off and phone for help.
- Press the test button on each smoke and carbon monoxide alarm, and change batteries in any that use them.
- Rake leaves away from a heat pump's coil, and from any intake and exhaust pipes coming out of a side wall.
- If the house has a humidifier, fit a new pad and open its water supply.
- Technician: on a gas furnace, ask for the ignition parts, burners and flame sensor to be checked, the heat exchanger looked over, gas pressure set and combustion measured; on a heat pump, the defrost board, reversing valve and backup strips.
Midwinter
- Following snow, clear the furnace's plastic vent pipes with a gloved hand or a soft brush.
- Keep snow and roof drip off the heat pump, and let its defrost cycles finish on their own.
- Keep a tally of the days the thermostat flags backup heat, and mention it at the next visit.
- Condensation or frost on the inside of the glass is a cue to turn humidification down.
- Pull the filter more often while the furnace is running for hours at a stretch.
After a storm or a power cut
- When the power comes back, give it a short while before restarting, and check whether the thermostat kept its settings.
- Look over the outdoor unit for fallen limbs, crushed fins, a pad knocked out of level or debris inside the casing.
- If water reached the furnace, air handler or outdoor unit's base, leave the system off until a technician has checked it.
- Take pictures of anything damaged before moving or cleaning it, in case the insurer wants them.
When to phone for service
Some things are past owner work. Call if a breaker keeps tripping after a reset, if the system cycles on and off in short bursts, if water pools near the indoor equipment, or if a burner flame turns yellow or lazy or soot shows around the furnace. If a carbon monoxide alarm sounds, leave the house with everyone in it and call from outside.
Before you agree to a replacement
A large repair estimate is a good moment to ask the same company to price a replacement as well. Questions for that quote:
- Is the proposed size backed by a room-by-room load calculation, and is the report part of the paperwork?
- What is the AHRI reference for the exact pairing of indoor and outdoor equipment?
- Are duct testing and sealing in the quoted price?
- What state license or registration, if any, covers this work, and what is the number?
- Who arranges the permits and inspection for the installation?
- Will you provide proof of liability coverage and workers' compensation before work starts?
A running service log
Pin a page inside the furnace room door, or start a phone note. Record the filter size and each change, the date and findings of every service call, refrigerant added, parts swapped, and the model and serial numbers of each piece of equipment. With that page in hand, the next technician starts from facts, and a warranty claim has dates behind it.