What Should You Ask Before Water Heater Installation?
These questions ensure you get the right unit, a code-compliant installation, and a clear understanding of total cost.
What Size Unit Do I Need for My Household?
For tank units: ask the installer to confirm the appropriate tank size based on household size. A 40-gallon tank is typically adequate for 2 to 3 people; 50 gallons for 3 to 4 people; 75 gallons for 5+ people. Ask about the first-hour rating (FHR) — the amount of hot water the unit can deliver in the first hour of peak use — rather than just tank capacity. For tankless: ask for the flow rate calculation based on simultaneous fixture demand and local ground water temperature. (For more on this, see How to Find the Best Water Heater Installer.) The Department of Energy compares storage, tankless, and heat pump water heaters and explains how to size a replacement.
Is the Expansion Tank Included and Required?
Ask whether an expansion tank is required by code for your system (most closed-loop systems require one) and whether it is included in the quote. A closed-loop system (any system with a backflow preventer or pressure reducing valve) requires a thermal expansion tank. If the old installation did not have one: the inspection may require it as a condition of passing. Confirm it is in the scope.
What Is the Full Installed Price Including the Permit?
Ask for the all-in total: unit, installation labor, permit, expansion tank, T&P valve, and disposal of the old unit. These items are commonly itemized separately or excluded from a base quote. The all-in price is the relevant comparison number when evaluating multiple quotes.
What Is the Unit’s Warranty and How Do I Register?
Ask for the warranty terms and, importantly, whether the installer registers the unit with the manufacturer or whether that is your responsibility. Most manufacturers require registration within 60 to 90 days of installation for the extended warranty to apply. An unregistered unit defaults to the shorter base warranty — a meaningful difference on a $1,500 to $3,500 investment.
Working With a Contractor on This Project
Getting the right outcome on any home services project starts before the work begins. A few consistent practices make the difference between a smooth project and a frustrating one.
Get at least two or three quotes. A single quote gives you no basis for comparison. Two or three quotes reveal the market rate for the work, expose scope differences between bidders, and let you assess contractor communication quality before any commitment is made. The lowest bid is not automatically the best value if the scope is thin or the materials are underspecified.
Ask for licenses and insurance before work starts. Verify current general liability insurance and, for any work involving workers on your property, workers compensation coverage. Licensing requirements vary by state and trade; confirm the specific requirements in your jurisdiction. A licensed contractor who carries appropriate insurance protects both parties if something goes wrong during the project.
Get the scope in writing. A written proposal that specifies materials, labor scope, timeline, what is included (permits, cleanup, disposal), and warranty terms is the foundation of a professional engagement. Verbal agreements on any of these points invite misunderstanding. For any project over $500, written scope is non-negotiable.
Clarify the payment schedule upfront. A reasonable payment schedule ties major payments to project milestones: a deposit at signing, a payment at material delivery or project start, and a final payment at completion after a walkthrough confirms satisfaction. A contractor who requires full payment upfront before work begins is a red flag in any trade.
Making a Confident Decision
The information in this article is designed to help you ask better questions of the professionals you work with, evaluate their answers with more confidence, and understand the decisions involved in this type of home services project. It is not a substitute for professional assessment of your specific home.
Every home is different. Roof slopes, local weather, tree exposure, soil conditions, and existing system condition all affect what the right solution is for your specific situation. The general principles here apply broadly, but a professional who assesses your home in person will give you guidance that accounts for the details that general articles cannot.
When you are ready to move forward, getting at least two or three quotes from licensed, insured, local contractors is the most important practical step. It lets you compare approaches, assess contractor quality, and confirm that the solution proposed matches your specific situation and budget.
Water Heater Service Cost at a Glance
Common repair (thermostat, element, valve): $150 to $600 — depends on the part and heater type.
New tank water heater installed: $1,000 to $2,500 — varies by size and any plumbing changes.
New tankless water heater installed: $2,000 to $3,500 — higher upfront cost, better long-term efficiency.
Overall range: $150 to $3,500, averaging $1,000 for most residential water heater services.
Ranges here are national ballpark figures, not quotes. Actual pricing varies by region, home condition, materials, and contractor. How we source cost data.