Furnace, boiler, oil burner and AC cleanings, by fuel
What an annual cleaning actually involves, by fuel
Maintenance is the least dramatic thing an HVAC company does, and the part that decides how a system ages.
Unity Heating & Air Conditioning is owner-run out of Macungie, and Tyler Furbacher does the cleanings himself. A cleaning is measurement, not a walkaround.
Oil needs cleaning every year without exception. Gas fouls far more slowly but still needs inspection, because what fails on a gas appliance fails quietly.
Oil: the one cleaning nobody skips
No. 2 oil burns dirty next to gas. Soot builds on the heat exchanger and flue passages, and soot insulates, so heat meant for the house goes up the chimney. Sulphur meets moisture and forms acidic deposits that eat metal. All of it in one season, which is why oil furnaces and oil boilers are cleaned annually, no exceptions.
What the annual oil cleaning covers
- Brushing and vacuuming the heat exchanger, flue passages and breeching
- A new nozzle matched to the burner’s rated firing rate and spray pattern, plus a new oil filter and strainer
- Electrodes set to the specified gap and position, blast tube and end cone cleaned, ignition and cad cell checked
- Pump pressure set, then combustion analysis: oxygen or carbon dioxide, stack temperature, carbon monoxide, smoke number and draft
Without an analyzer that last step is guesswork.
Gas furnace tune-up
A natural gas or propane furnace fouls slowly, so the work shifts to inspection. The heat exchanger is examined for cracking and corrosion. Burners and the flame sensor are cleaned, since an oxide-coated sensor is why a furnace lights then drops out seconds later. Inlet and manifold gas pressure are checked against the rating plate.
Temperature rise across the exchanger is measured against the range on that plate, the fastest way to catch an airflow problem. Then the blower wheel and filter, venting, the condensate trap on a high-efficiency unit, the safeties, and a carbon monoxide check.
Boiler cleaning
A boiler gets the fireside cleaning its fuel calls for, and an oil-fired boiler gets the whole list above. The low-water cutoff is tested and flushed, because an untested cutoff is a safety device nobody has confirmed works.
The expansion tank is checked for charge and waterlogging, since a waterlogged tank drives pressure up and sets relief valves dripping. System pressure, the relief valve, the circulator and the aquastat get reviewed, and air is bled so the far end of the loop heats.
Air conditioning and heat pump tune-up
Both coils get cleaned on central air conditioning. A dirt film on the outdoor coil raises head pressure, which raises compressor draw while cutting capacity.
Charge is verified by superheat on a fixed-orifice system and subcooling on one with a metering valve, not by gauge pressure and a hunch. A system genuinely low has a leak worth finding, not topping off. Capacitor microfarads are measured, contactor points checked for pitting, the condensate drain cleared, airflow verified.
A heat pump adds the reversing valve and defrost cycle, and a ductless mini split lives or dies on its blower wheel and indoor coil, a real cleaning job rather than a rinse.
Filters and airflow matter more than people think
A restricted filter raises static pressure and cuts airflow. In heating, low airflow pushes temperature rise past the plate range and cycles the furnace on its limit. In cooling, it freezes the coil solid. Neither is a refrigerant problem, though both get treated as one.
A thick high-MERV filter in a one-inch slot chokes a system never designed for it. Better filtration belongs in a media cabinet, part of a real indoor air quality plan.
How often, and what it does not do
Heating once a year, before the season rather than during the first cold snap. Cooling once a year, in spring. A heat pump gets checked twice, since it works both seasons with no off-season.
Maintenance catches failures while they are cheap, holds efficiency near where the equipment started and tells you what shape a system is in. It does not make an old furnace new, repair a cracked heat exchanger, or fix undersized ductwork.
Frequently asked questions about maintenance
My furnace runs fine. Do I really need a cleaning?
On oil, yes, every year, because soot and acidic deposits build whether it runs well or not. On gas the case is inspection: a cracked heat exchanger, a failing pressure switch or a corroded vent connector gives no symptom until it stops.
When should I book, and how long does it take?
Heating in late summer or fall, cooling in spring, ahead of the rush. A straightforward gas furnace or air conditioner runs about an hour. An oil cleaning takes longer, because the exchanger is brushed out and the combustion numbers set afterward, not assumed.
How often should I change the filter?
Check a one-inch filter monthly and change it when light no longer passes through, which with pets means every month. A four-inch media filter usually runs six months to a year. Filter changes are the one piece of maintenance a homeowner controls.
Book a cleaning or tune-up
Call Unity Heating & Air Conditioning at (267) 644-9516 to get on the schedule, or send details through the contact page. Cleanings run out of Macungie across Lehigh and Northampton counties and upper Bucks. Calls are answered around the clock.
