In Plain English
Quick Answer
The appliance that heats water for showers, sinks, and appliances — either storing hot water in a tank or heating it on demand.
Definition
Definition
An appliance that heats and stores (storage type) or heats on demand (tankless type) domestic hot water for distribution throughout a building. Water heaters are fueled by natural gas, propane, electricity, or solar energy and are sized in gallons (storage) or BTU/hour input (tankless). First-hour rating and recovery rate determine performance for a given occupancy load.
Context
Why It Matters in Bidding
The water heater is a high-dollar equipment item whose sizing, fuel type, and venting drive both the plumbing bid and coordination with the electrical or gas scope. Choosing the wrong type or capacity at bid time can mean a major change order, and tankless units in particular add gas-line, venting, and electrical work other trades must price.
Example
Example
On a restaurant build-out, the estimator prices two tankless gas water heaters sized to the kitchen demand, then coordinates with the gas and electrical subs so the upsized gas line and dedicated circuit are carried in their bids instead of surfacing as a change.
See Also
Related Terms
FAQ
Questions Contractors Ask
What drives water heater cost in a construction estimate?
Fuel type, capacity, and venting requirements drive most of it. Tankless units cost more for the device and add gas-line upsizing, combustion venting, and electrical work that other trades must carry. Estimators price the specified model and the cross-trade coordination, not just the unit, to avoid gaps at award.
How do estimators size a water heater for a bid?
They work from the design engineer's specified model and capacity rather than sizing it themselves, but verify the schedule matches occupancy demand. For storage units they confirm gallons and recovery rate; for tankless they confirm BTU/hour input. Mismatched sizing flagged late becomes a costly equipment and venting change order.
Why does water heater type affect other trades' scope?
Tankless and gas-fired units need larger gas lines, combustion air, and dedicated venting, while electric units need adequate circuits and panel capacity. The plumbing estimator must flag these so the gas and electrical subs price the supporting work; otherwise the coordination cost appears as a change order after the contract is signed.
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