HVAC Repair in Dover, NH
Homes here need heat from October through May and cooling from July through August. If your system quits, tell us what it's doing and a licensed contractor who covers Strafford County will get in touch.
Tell us about the job
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Ten months of runtime, and nights near zero
Your furnace works from October through May here, and most of the two months it gets a break, the air conditioner is running instead. Winter nights average 16°F, cold enough that the burner cycles on and off many times a night to keep up, and each cycle puts wear on the igniter and the ignition control board. When one of those fails, the furnace won't light at all.
Fuel oil heats 42.5% of homes in this area, and an oil furnace depends on the nozzle and the burner staying clean to fire correctly. Come summer, the same system switches over and cools the house through afternoons near 79°F. This county has seen 44 winter storms and 43 damaging wind events over the past ten years, and in New Hampshire, 22% of households went at least 24 hours without power in 2024. A furnace that was running fine before an outage can come back with a tripped switch or a dead board.
- 8 months
- October through May, your system heats
- 2 months
- July through August, it cools
- 16°F
- the average winter night it heats against
- 79°F
- the average summer afternoon it cools against
NOAA nClimDiv, 1991–2020 normals
New Hampshire has no state license for HVAC contractors.
New Hampshire has no state license and no state registration for HVAC contractors. There is no test behind the name on the truck and no state file to check against it. That is true everywhere in the state, including Strafford County.
For a repair on a heating and cooling system, that means the license itself is not the thing standing behind the work, because there is not one. If the job includes a gas connection, that connection is the part of the job with the least room for error, and no state license stands behind whoever makes it here.
Source: New Hampshire General Court
- Why is my heat not working?
- The most common cause is the igniter or flame sensor failing, which stops the furnace from lighting even though it still runs. A dirty flame sensor reads a weak flame as no flame and shuts the burner off as a safety measure. A tripped breaker or a thermostat with dead batteries can look like the same problem, so check those first. With winter lows here averaging 16°F, a furnace that will not light needs a contractor out quickly, since a home can lose heat fast in that kind of cold.
- Why is my system running but not cooling the house?
- If the blower is running but the air is not cold, the system is likely low on refrigerant or the coil is frozen over. A frozen coil often starts with restricted airflow, usually a dirty filter, and once ice builds up the system can run for hours without cooling anything. Low refrigerant means a leak somewhere in the line, and that only gets fixed by finding and sealing the leak, not by adding more refrigerant. Either way the system needs a contractor to look at it, since running it while the coil is frozen can damage the compressor.
- What can I check before calling for HVAC repair?
- Check the thermostat first. Confirm it is set to heat or cool as needed, the batteries are good, and the display is on. Next check the breaker for the system, since a tripped breaker will stop it cold with no other warning. Then look at the filter. A filter clogged with dust chokes off airflow and can cause problems that look like something worse. If those are all fine and the system still is not working right, that points to something inside it that needs a contractor to diagnose.