Heating Systems Guides & Calculators
44 expert guides covering furnaces, space heaters, water heaters, sizing calculators, and more
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Furnaces & Central Heating
Gas, electric, and oil furnaces, boilers, and central heating systems
Best Electric Furnace Brands & Cost (2026 Buyer's Guide)
The best electric furnaces in 2026 from Goodman, Rheem, Carrier, and more. Equipment costs $800-$2,500 with installation totaling $2,000-$5,500. Full brand comparison with specs and pricing.
Best Gas Furnace Brands: Cost & Efficiency Compared (2026)
We ranked every major gas furnace brand in 2026 by efficiency, reliability, warranty, and cost. See side-by-side data for Carrier, Trane, Lennox, Goodman, Rheem, Bryant, York, and more.
Best Oil Furnace: Prices, Efficiency & Reviews (2026)
The best oil furnaces in 2026 from Beckett, Thermo Pride, Adams, and others. Equipment costs $2,500-$6,000 with installation at $5,000-$10,000. Full brand comparison and buyer's guide.
Cold Air Return Vents: What They Are & How Many You Need
Cold air returns pull room-temperature air back to the furnace for reheating. Most homes need one return per room or 1 sq inch of return per 1 CFM of airflow. Here's how to check if you have enough.
Cracked Heat Exchanger: 6 Symptoms & What to Do Next
A cracked heat exchanger can leak carbon monoxide into your home. Learn the 6 warning signs, how to confirm the crack, repair vs replacement costs, and when to act immediately.
What Does a Dirty Furnace Filter Look Like? (4 Stages)
See exactly what a dirty furnace filter looks like at each stage — from slightly used to dangerously clogged. Photo comparison guide to know when your filter needs replacing.
Do Furnaces Have Pilot Lights? Which Ones Still Do (and Which Don't)
Most furnaces made after 2010 don't have pilot lights — they use electronic ignition instead. Here's how to tell which type you have and what to do if your pilot light goes out.
Furnace Blowing Cold Air: 7 Causes & Easy Fixes
Your furnace is running but blowing cold air? The 7 most common causes are a thermostat fan set to ON, a dirty filter, or a failed flame sensor. Here's how to fix each one fast.
Furnace Efficiency Ratings: What AFUE Really Means (2026 Guide)
AFUE measures what percentage of fuel your furnace converts to usable heat. An 96% AFUE furnace turns 96 cents of every gas dollar into heat. Here's how to read, compare, and use AFUE ratings.
Furnace Filter Direction: Which Way Does the Arrow Go?
The arrow on your furnace filter should point TOWARD the furnace (toward the blower motor). Here's exactly how to install it correctly for every furnace configuration.
Furnace Filter MERV Rating: Which MERV Filter Is Best for Your Home?
MERV 8–11 is the sweet spot for most homes — capturing dust, pollen, and pet dander without restricting airflow. Here's the complete MERV rating chart with recommendations by situation.
How to Tell If Furnace Flame Sensor Is Bad (Symptoms & Fix)
A bad flame sensor causes the furnace to ignite then shut off within 3-10 seconds. Here's how to diagnose it, clean it (10-minute DIY fix), and when to replace it.
Furnaces: Complete Homeowner's Guide (Gas, Electric, Oil) — 2026
Everything you need to know about furnaces in 2026 — gas, electric, and oil types compared by cost, efficiency, lifespan, and performance. Covers sizing, installation, maintenance, and when to replace.
Furnace Installation Cost: What to Expect in 2026
The average furnace installation costs $3,500–$8,500 in 2026 for a gas furnace, $2,000–$5,500 for electric, and $5,000–$10,000 for oil. Full breakdown of equipment, labor, permits, and hidden costs.
Furnace Leaking Water: 7 Causes & How to Fix Each One
Water pooling around your furnace? The 7 most common causes are a clogged condensate drain, cracked heat exchanger, or humidifier leak. Here's how to diagnose and fix each one.
Furnace vs Heat Pump: Which Is Better? (14 Differences Compared)
Furnace vs heat pump compared across 14 factors including cost, efficiency, climate suitability, lifespan, and comfort. Data tables and real-world examples help you decide which system is right for your home.
How Many Watts Does a Gas Furnace Use? (Blower Motor Power)
A gas furnace uses 300-800 watts during operation, mostly from the blower motor. Variable-speed blowers use 75-200W on low; single-speed use 400-700W. Full breakdown with generator sizing guide.
Gas vs Electric Heating: Which Is Cheaper? (2026 Cost Calculator)
Compare gas vs electric heating costs with real data. Average gas heating costs $600–$1,200/year vs $1,200–$2,500/year for electric. Use our calculator with your local rates for an exact comparison.
How Long Do Furnaces Last? (Lifespan by Type + Replacement Signs)
Gas furnaces last 15-25 years (average 18-20), electric furnaces 20-30 years, and oil furnaces 15-25 years. Here are the 10 signs it's time to replace yours.
How Much Gas Does a Pilot Light Use? (Cost Per Month in 2026)
A standing pilot light uses 600-1,800 BTU/hour, burning roughly 5-12 therms of gas per month at a cost of $5-$13/month. Here's the exact math and whether to upgrade to electronic ignition.
Thermostat Says Heat On But No Heat: 14 Causes to Check
Thermostat says heat is on but your house is cold? Check these 14 causes from easiest to hardest — including thermostat settings, tripped breakers, dirty flame sensors, and gas valve failures.
What Temperature to Set Thermostat in Winter? (Savings Calculator)
The DOE recommends 68°F when home and 60-62°F at night or when away. Every 1°F lower saves roughly 1-3% on heating costs. See our savings chart and schedule recommendations.
Upflow vs Downflow Furnace: What's the Difference? (Guide)
An upflow furnace draws air from the bottom and pushes it up; a downflow pulls from the top and pushes down. Your home's layout determines which type you need. Here's how to choose.
Tankless Water Heaters
On-demand water heating systems and sizing guides
Best Electric Tankless Water Heaters in 2026 (240V, 50–150A)
The 10 best electric tankless water heaters in 2026, ranked by kW output, UEF, and real-world GPM at various temperature rises. Covers whole-home, point-of-use, and compact models with full electrical requirements.
Best Gas Tankless Water Heaters in 2026 (Natural Gas & Propane)
The 10 best gas tankless water heaters ranked by efficiency, flow rate, and real-world performance. Covers natural gas and propane (LP) models, condensing vs non-condensing, and sizing for every climate.
Best Tankless Water Heaters in 2026 (Based on Specs, Not Sponsors)
The 12 best tankless water heaters in 2026, ranked by UEF efficiency, flow rate, and real-world performance data. Gas condensing, non-condensing, and electric models compared by specs.
Electric vs Gas Tankless Water Heater: Full 2026 Comparison
Definitive comparison of electric vs gas tankless water heaters: efficiency, flow rate, installation cost, operating cost, climate suitability, and which type wins for your specific situation.
Hot Water Recirculating Pumps Explained (+ How They Work With Tankless)
Complete guide to hot water recirculating pumps in 2026: how they work, types (dedicated vs demand vs timer), costs, installation with tank and tankless heaters, energy impact, and best models.
Is a Tankless Water Heater Worth It in 2026? (ROI Calculator + Data)
Data-driven analysis of whether a tankless water heater is worth the investment. Includes ROI calculations, payback periods by scenario, total cost of ownership over 20 years, and an interactive ROI calculator.
Best Outdoor Portable Tankless Water Heaters in 2026 (Camping, RV, Off-Grid)
The 8 best portable tankless water heaters for camping, RVs, outdoor showers, and off-grid use in 2026. Propane and battery-powered models ranked by GPM, portability, and real-world performance.
Smallest Tankless Water Heaters in 2026 (Compact Gas + Electric)
The most compact tankless water heaters in 2026 for tight spaces. Mini gas and electric models ranked by physical dimensions, output capacity, and best use cases for apartments, RVs, and under-sink installs.
Tankless vs Tank Water Heater: Which Saves More in 2026?
Head-to-head comparison of tankless vs tank water heaters across every metric: cost, efficiency, lifespan, flow rate, installation, maintenance, and 20-year total cost of ownership with real data.
Tankless Water Heater Breaker Size Calculator (2026 NEC Guide)
Calculate the exact breaker size for any electric tankless water heater. Covers NEC requirements, circuit configurations for 8–36 kW units, panel capacity assessment, and common wiring mistakes to avoid.
How Much Does a Tankless Water Heater Cost in 2026? (Unit + Installation)
Complete 2026 cost breakdown for tankless water heaters: unit prices, installation labor, electrical/gas work, permits, and total installed costs for every type. Includes regional pricing and tax credits.
How Much Electricity Does a Tankless Water Heater Use? (kWh Breakdown)
Exact electricity usage for electric tankless water heaters in 2026: kWh per day, month, and year by unit size. Includes cost calculations at various electricity rates and comparison to tank heaters.
Tankless Water Heaters: Complete Guide (Gas vs Electric) — 2026
Everything you need to know about tankless water heaters in 2026. Compare gas vs electric models, learn sizing, installation requirements, costs, efficiency ratings, and which type fits your home.
How Much Propane Does a Tankless Water Heater Use? (Gallons + Cost)
Exact propane usage for tankless water heaters: gallons per day, month, and year by unit size and usage. Includes cost calculations, tank sizing requirements, and comparison to propane tank heaters.
Tankless Water Heater Wire Size Calculator (AWG Guide for 2026)
Calculate the correct wire size (AWG) for any electric tankless water heater. Covers NEC requirements, voltage drop calculations, wire types, conduit sizing, and distance-based upsizing tables.
Water Heaters
Traditional tank water heaters and maintenance guides
Best Water Heaters in 2026: Tank & Tankless Models Compared
Data-backed rankings of the best water heaters in 2026 including tank, tankless, and heat pump models. Covers efficiency ratings, real-world performance, pricing, and which model fits your home.
Electric Water Heating Cost & kWh Usage: State-by-State Analysis (2026)
Detailed breakdown of electric water heating costs across all 50 states in 2026. Includes kWh usage data, monthly and annual cost estimates by household size, and strategies to reduce your electric water heating bill.
Heat Pump Water Heaters: Are They Worth It? Complete Hybrid Guide (2026)
In-depth guide to heat pump water heaters (hybrid) in 2026. Covers how they work, efficiency ratings, installation requirements, costs vs savings, climate considerations, and whether a HPWH is right for your home.
How Long Does a Water Heater Last? Lifespan Data & Replacement Signs (2026)
Data-backed analysis of water heater lifespans by type and fuel source. Learn the warning signs of failure, when to repair vs replace, and how maintenance extends your water heater's life.
Water Heater Installation Cost: What to Budget in 2026
Complete breakdown of water heater installation costs in 2026. Covers tank, tankless, and heat pump models by fuel type, with labor rates, material costs, permit fees, and real-world examples.
Water Heaters: Complete Guide to Tank vs Tankless, Sizing & Efficiency (2026)
Comprehensive water heater guide covering tank vs tankless comparisons, proper sizing calculations, energy efficiency ratings, fuel types, and how to choose the right water heater for your home in 2026.
Most Popular This Month
Best Gas Furnace Brands: Cost & Efficiency Compared (2026)
We ranked every major gas furnace brand in 2026 by efficiency, reliability, warranty, and cost. See side-by-side data for Carrier, Trane, Lennox, Goodman, Rheem, Bryant, York, and more.
Furnaces: Complete Homeowner's Guide (Gas, Electric, Oil) — 2026
Everything you need to know about furnaces in 2026 — gas, electric, and oil types compared by cost, efficiency, lifespan, and performance. Covers sizing, installation, maintenance, and when to replace.
Furnace vs Heat Pump: Which Is Better? (14 Differences Compared)
Furnace vs heat pump compared across 14 factors including cost, efficiency, climate suitability, lifespan, and comfort. Data tables and real-world examples help you decide which system is right for your home.
Gas vs Electric Heating: Which Is Cheaper? (2026 Cost Calculator)
Compare gas vs electric heating costs with real data. Average gas heating costs $600–$1,200/year vs $1,200–$2,500/year for electric. Use our calculator with your local rates for an exact comparison.
Best Tankless Water Heaters in 2026 (Based on Specs, Not Sponsors)
The 12 best tankless water heaters in 2026, ranked by UEF efficiency, flow rate, and real-world performance data. Gas condensing, non-condensing, and electric models compared by specs.
Tankless Water Heaters: Complete Guide (Gas vs Electric) — 2026
Everything you need to know about tankless water heaters in 2026. Compare gas vs electric models, learn sizing, installation requirements, costs, efficiency ratings, and which type fits your home.