Water heater replacement cost in Dedham, MA depends on five things more than on the brand sticker: the type of heater, the fuel, the venting, the code items around the tank, and how much of the old setup has to be rebuilt.
We are not printing dollar figures here, because a number copied from a national chart would not match your house. What you can do is learn what a quote should list and ask each plumber the same questions.
If your tank is leaking now, shut off the cold water supply to it and turn off the power or gas control. Then call.
What goes into a replacement quote.
A clear quote has line items you can see. A single lump sum with no detail makes comparison impossible.
- The heater itself, with capacity, fuel and efficiency type named..
- Labor to drain, disconnect and remove the old unit and haul it away..
- New connections: flexible supply lines, shutoff valves, a gas flex connector or electrical whip as needed..
- The temperature and pressure relief valve discharge pipe and, where the code calls for it, a safe waste pan..
- Venting changes, if you are moving from a standard atmospheric vent to power vent, direct vent or a new chimney liner..
- The permit, pulled by the licensed plumber who does the work..
- An expansion tank if your system needs one, and any gas line or electrical upgrades..
Anything outside that list, like a drywall patch, a new floor drain or a closet rebuild, should be named separately so you know what you agreed to.
Tank, tankless or heat pump: how the options compare.
The type you pick moves the price more than anything else. Think of it as a trade between purchase cost, installation work and running cost.
| Option | Typical installation work | Trade-off. |
|---|---|---|
| Standard tank, like for like | Lowest. Same location, same fuel, same vent | Short answer for a failed unit, but least efficient. |
| Power vent tank | Needs an outlet for the blower and PVC venting | Flexible vent routing, more parts that can fail. |
| Tankless gas | Larger gas line, new stainless or approved venting, condensate drain | More upfront work, endless hot water at the limits of flow rate. |
| Heat pump (hybrid) | Needs space, airflow and a condensate path, plus a 240-volt circuit | Higher purchase cost, much lower electric use, cools the room. |
Heat pump heaters can reduce running costs, but we make no rebate claims here. If a plumber or ad mentions an incentive, ask where the program is published and read its terms yourself. Our tankless water heater page describes what that conversion involves in more detail.
Need a clear price on a new water heater? Call and ask what the quote covers.
Call (617) 752-0573What Dedham homeowners should know.
Water in Dedham comes from the Dedham-Westwood Water District. Its 2025 water quality report lists hardness at 4.3 to 7.8 grains per gallon with an average of 6.0, mostly calcium and magnesium. That is moderately hard water. Over years, scale builds up on the bottom of a tank and on tankless heat exchangers.
What does this mean for you? Plan maintenance into the decision. A tank heater benefits from periodic flushing, and a tankless unit needs regular descaling to keep its flow and efficiency. When a plumber quotes you, ask how often they recommend servicing the unit in this water and what the service involves.
The same report says the District's pH averages 8.0 and that it adds treatment so water is not corrosive to pipes. It does not tell you how long a given heater will last. Do not assume a long warranty makes up for neglected maintenance.
Permit, relief valve and waste pan items.
Massachusetts treats a water heater swap as plumbing work. According to the Mass.gov consumer fact sheet, permits for plumbing work are issued only to licensed plumbers, and replacing plumbing needs a permit from the local plumbing inspector. In Dedham the Building Department has a Plumbing/Gas Division, so ask the plumber to confirm they will pull the permit and that the fee is itemized.
Two code items often appear in a quote. Under 248 CMR 10.14, a water heater capable of exceeding 212 degrees Fahrenheit needs a temperature and pressure relief valve. Its discharge pipe must be full size, made of non-ferrous material, have no shutoff, and end at a fixture or within 12 inches of the floor. Tank-type heaters also need a vacuum relief valve.
The second is the safe waste pan. Mass.gov's policy statement says heaters and boilers of 6 gallons or more installed above an occupied space need a pan piped to a trapped fixture or within 12 inches of the floor.
For replacements there is an exception that uses an approved automatic shutoff device plus a pan. If your heater sits over finished living space, that item will affect the price. Ask which version the plumber plans to use.
Repair or replace: a simple decision guide.
A leak from the tank body, from the bottom or from a rusted seam means the steel shell has failed, and replacement is the fix. A leak from a fitting, valve or relief valve line can sometimes be repaired.
Use these questions to lean one way or the other:
- Is water coming out of the tank itself? Replace..
- Is the problem a failed thermostat, element or igniter on a tank that is otherwise sound? A repair may be reasonable..
- Is the tank old enough that you do not know its age? Look at the data plate and ask the plumber to decode the serial number..
- Are you paying to repair a unit that will need replacement within a short time? Compare the repair bill with the replacement quote..
Our water heater replacement page explains how a failed-tank call works, and water heater installation covers planned swaps and fuel changes.
How to compare two quotes.
- Same capacity and fuel on both bids, or a clear reason for the difference.
- Permit, haul-away and disposal listed, not implied.
- Relief valve discharge pipe and waste pan addressed in writing.
- Venting changes described, including who patches any wall or roof openings.
- Whether an expansion tank and shutoff valves are included.
- Warranty terms in writing, and what the warranty does not cover, like labor.
- The licensed plumber's license type shown on the paperwork, which you can verify through the state's online license lookup.
Nearby towns.
If you are weighing bids for a house in Norwood or Walpole, use the same checklist. Local permit procedures differ, so ask your own building department how it handles water heater permits.
Frequently asked questions.
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The Mass.gov consumer fact sheet says only licensed plumbers may do plumbing work and that permits are issued only to licensed plumbers. Gas and venting add risk. Hire a licensed plumber, and ask for the permit to be pulled.
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Because the heater is only part of the job. A tankless unit usually needs a larger gas line, a different vent and a condensate drain, and sometimes new electrical work. Ask for those items on the quote separately.
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Hard water leaves scale, and the 2025 district report puts average hardness at 6.0 grains per gallon. Scale reduces efficiency and can cause noise. Regular flushing helps. We cannot predict lifespan from hardness alone.
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Policies generally cover sudden and accidental damage rather than wear and tear. A heater that simply wore out is usually not covered, but water damage from a sudden failure might be. Ask your insurer.
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Shut off the cold water valve above the tank. Turn off the breaker for an electric unit, or set a gas unit to its off setting. Do not touch the gas supply lines. Then call for a priced plan.
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The licensed plumber pulls the permit, and the Town's plumbing inspector inspects the work. Ask whether the plumber schedules that inspection for you, and request a copy of the permit.
Codes, standards and sources.
Plumbing work in Massachusetts is governed by 248 CMR 10.00, the Uniform State Plumbing Code, and plumbers are licensed by the Board of State Examiners of Plumbers and Gas Fitters. You can read the state's consumer fact sheet on plumbers and gas fitters before you hire anyone.
Local facts on this page come from the Dedham-Westwood Water District, the Town of Dedham, the other towns named and Mass.gov, and were checked in October 2026. Where a fact could not be confirmed, the page says to ask the utility or the town.