Why Is My Heating Bill So High? 12 Causes and How to Lower It

Quick answer: A higher heating bill usually comes from colder weather, a rate increase, or more time at home. Compare your usage (therms of gas or kilowatt-hours of electricity) with the same month last year before assuming something is wrong. If usage jumped more than the weather explains, look at the equipment: a clogged filter, short cycling, leaky ducts, a misbehaving thermostat, a heat pump stuck on backup heat or an aging furnace can all waste fuel. A heating tune-up is the fastest way to find out.

A surprise bill in January is frustrating, and it's not always clear whether the cause is the weather or the furnace. This guide helps you work out which, and what to fix first.

Start with your bill, not the furnace

Your utility bill holds most of the clues. Look for:

• Usage, measured in therms for gas or kWh for electricity, not just dollars
• Billing period length, since some months have more days than others
• Rates and charges, including supply, delivery and any changes
• Usage history, which many bills or online accounts show by month for the past year
• Estimated vs actual reading, because estimated bills can be corrected later

If usage is similar to last year but the total is higher, rates are the likely cause. If usage is much higher, keep reading.

The weather factor

Heating use rises sharply as temperatures fall. A colder-than-usual month can raise usage significantly, with nothing wrong at all. Many utilities show "degree days" or average temperatures on the bill to help you compare. Inland homes in places like Jackson, Manchester and the Pine Barrens typically see colder nights than the immediate shore.

12 common causes of a high heating bill

1. Clogged air filter

Restricted airflow makes the furnace run longer and hotter, and can trigger short cycling. Check it first. See which way the furnace filter goes.

2. Short cycling

Frequent on-off cycles waste fuel, because startup is the least efficient part of each cycle. See furnace keeps shutting off and short cycling.

3. Leaky or uninsulated ductwork

Ducts in attics, crawl spaces and garages can lose a large share of heated air before it reaches your rooms. See duct sealing.

4. Thermostat problems

A thermostat in a cold draft or with a dead battery, a wrong setting or a fan left on "On" can all drive up use. See thermostat troubleshooting and best thermostat settings.

5. Heat pump running on backup heat

Electric heat strips use much more electricity than the heat pump itself. Big setbacks, low refrigerant or control problems can keep them running. See emergency heat vs aux heat and heat pump not heating.

6. Aging, low-efficiency furnace or boiler

Older equipment turns less of its fuel into heat, and efficiency can drop further without maintenance. See signs you need a new furnace and is a high-efficiency furnace worth it.

7. Skipped maintenance

Dirty burners, a weak flame and poor combustion waste fuel. An annual tune-up adjusts and cleans them.

8. Air leaks and poor insulation

Drafty windows, doors, attic hatches and rim joists let heat escape. Older homes in towns with many pre-1960 houses, such as Riverside, Red Bank or Perth Amboy, often have more of these. See how old homes are in each town.

9. Electric resistance heat

Baseboard heaters and electric furnaces cost more to run than most other heating. See how NJ homes heat.

10. Space heaters

Several space heaters running for hours can add up quickly on an electric bill. See space heater safety.

11. Hot water

Your water heater uses energy too, and more in winter because incoming water is colder. See water heater temperature setting.

12. Boiler and radiator issues

Air in the system, cold radiators and pressure problems make a boiler run longer for the same comfort. See cold radiators and boiler banging noises.

Quick diagnosis table

What to fix first

Start with the cheapest fixes and work up:

1. Change the filter
2. Check thermostat settings and batteries
3. Close gaps: weatherstrip doors, seal obvious drafts
4. Book a tune-up: cleaning, combustion check, airflow and safety
5. Seal and insulate ducts in unheated spaces
6. Add attic insulation where it's thin
7. Consider replacing old equipment when repairs and bills keep climbing

Smart thermostat habits

• Use moderate setbacks at night and while away
• With a heat pump, avoid big setbacks that trigger backup heat
• Keep the fan on Auto
• Don't put lamps or TVs near the thermostat, because their heat misleads it

When replacement pays off

If your furnace or boiler is old, low efficiency and needs repeated repairs, replacing it can lower bills and improve comfort. Compare options with your own bills, not general claims. New Jersey Natural Gas customers may qualify for rebates and 0% APR financing on a new high efficiency furnace, boiler or water heater through NJNG's SAVEGREEN program (provided by NJNG, not Prime Comfort Group; terms and eligibility apply; see savegreen.com). Financing through Synchrony is also available, subject to credit approval. See HVAC financing in New Jersey.

See lower your heating and cooling bills and furnace replacement in New Jersey.

A weekend energy check you can do yourself

1. Feel for drafts around doors, windows, outlets on outside walls and the attic hatch on a windy day.
2. Look at the attic insulation. If you can see the tops of the floor joists, there's probably not enough.
3. Check exposed ducts in the basement, attic or garage for gaps, loose joints or missing insulation.
4. Listen to the furnace. Does it run constantly, or turn on and off every few minutes?
5. Check every room's vents are open and not blocked by furniture or rugs.
6. Compare two bills: this month and the same month last year, noting usage and average temperature.

Write down what you find. It makes a service visit faster and more useful.

What a heating tune-up checks for efficiency

• Burner cleaning and flame quality
• Combustion analysis on gas furnaces and boilers
• Gas pressure and temperature rise
• Blower and airflow
• Filter and duct connections at the furnace
• Thermostat calibration and settings
• Flame sensor, igniter and safety controls
• Carbon monoxide testing

When to call right away

Some high-bill situations are also safety or breakdown warnings. Call us if:

• The furnace runs constantly but the house stays cold
• You hear new banging, grinding or squealing noises
• You see soot, rust or water around the furnace or boiler
• The heat pump's outdoor unit stays iced over for hours
• Your carbon monoxide alarm has sounded (call 911 first)

Catching these early usually means a smaller repair and a lower bill.

Heating tune-ups and repairs near you

Our own licensed team services every brand across all 153 towns in Ocean, Monmouth, Burlington and Middlesex counties, including Toms River, Manchester, Old Bridge and Willingboro.

Book an $89 heating tune-up online or call (732) 779-7106 (terms apply).