Top 7 Water Heater Installation in Milwaukee, WI

Updated March 2026 · Based on licensing, reviews & response time

Quick Answer

The best water heater installation companies in Milwaukee, WI for 2026 include Knight Plumbing, Inc. (4.8), Optimal Plumbing (5), Diamond Plumbing Heating and Cooling (4.7). All install tank and tankless water heaters with same-day service available.

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1

O & W Heating and Cooling and Furnace, boiler, water heater install & repair

4379 S Howell Ave, Milwaukee, WI 53207, USA
★★★★½ 4.8 (215 reviews)
Licensed & InsuredTop Rated
Services: Water Heater Installation
2

Knight Plumbing, Inc.

4270 S Howell Ave, Milwaukee, WI 53207, USA
★★★★½ 4.8 (1,083 reviews)
Licensed & InsuredTop Rated
Services: Water Heater Installation
3

Midwest Water Heater

12610 W Hampton Ave, Butler, WI 53007, USA
★★★★½ 4.9 (64 reviews)
Licensed & InsuredTop Rated
Services: Water Heater Installation
4

West Allis Heating, Cooling, Plumbing, and Electrical

201 S Hawley Ct, Milwaukee, WI 53214, USA
★★★★½ 4.8 (2,257 reviews)
Licensed & Insured
Services: Water Heater Installation
5

Diamond Plumbing Heating and Cooling

1345 N Jefferson St Suite 163, Milwaukee, WI 53202, USA
★★★★½ 4.7 (173 reviews)
Licensed & Insured
Services: Water Heater Installation
6

Optimal Plumbing

7309 W Tripoli Ave, Milwaukee, WI 53220, USA
★★★★★ 5 (218 reviews)
Services: Water Heater Installation
7

Southport Home Services

1343 S 27th St, Caledonia, WI 53108, USA
★★★★½ 4.8 (2,081 reviews)
Services: Water Heater Installation

How We Ranked These Milwaukee Pros

Our rankings are based on a weighted evaluation of five key factors:

  1. Licensing & Insurance — All listed businesses hold active state licenses verified through official databases.
  2. Customer Reviews — We aggregate ratings from Google, Yelp, and the BBB, weighting recency and review volume.
  3. Response Time — Companies offering same-day or 24/7 emergency service score higher.
  4. Pricing Transparency — Businesses who offer flat-rate pricing or free estimates rank above those with opaque billing.
  5. Experience & Longevity — Years serving the Milwaukee market and breadth of services factor into overall reliability.

Rankings are reviewed quarterly. Have a correction? Contact us.

Frequently Asked Questions

How much does water heater installation cost in Milwaukee?

Water heater installation in Milwaukee costs $900-$1,500 for a standard tank model and $2,500-$5,000 for tankless. Includes unit, labor, permits, and old unit disposal.

How long does water heater installation take?

A standard tank replacement takes 2-4 hours. Tankless installation takes 4-8 hours due to venting and gas or electrical upgrades. Most Milwaukee companies offer same-day installation.

Do I need a permit for water heater installation?

Yes, most cities require a plumbing permit for water heater installation. Your installer should handle this. Unpermitted work can affect insurance claims and home resale.