Marathon (Rheem) Water Heaters Review 2026
Best lifetime tank warranty
UEF Range
0.9–0.95
Types
1
Price Range
$$$
Tank Warranty
Lifetime
Origin
USA
Why Marathon (Rheem)?
Best lifetime tank warranty. Trusted by Nassau County homeowners since 1925.
Part of Rheem Manufacturing
Is Marathon (Rheem) water heater any good?
Yes — Marathon (Rheem) water heaters are a premium-tier choice. Our editorial score is 4.2/5 based on published efficiency, climate fit, warranty, features, and price positioning. Marathon (Rheem) is associated with Rheem Manufacturing; confirm the exact model platform, parts path, and coverage rather than assuming they are shared. For a Long Island home, compare the exact matched system and written installation scope because design and commissioning can matter as much as the badge on the equipment.
Our Review Process
Ratings are editorial comparison scores—not customer reviews, installation counts, or manufacturer endorsements.
Marathon (Rheem) Water Heater Planning for Nassau County and Suffolk County
A useful Marathon (Rheem) comparison starts with the exact indoor and outdoor model pairing—not the brand name alone. Home+ Air & Heat can review Marathon (Rheem) water heater options for homes in our covered Nassau County, Suffolk County and the five NYC boroughs service areas, then document whether the proposed equipment, capacity, electrical scope, and installation approach fit the project.
Before work is authorized, ask for the design method, AHRI match where applicable, installer or dealer qualification required by the manufacturer, registration responsibility, parts coverage, labor coverage, exclusions, and current incentive assumptions in writing. Those details vary by model, project, contractor status, installation date, and current program rules.
Marathon (Rheem) Water Heater Reviews: Our Installer Assessment
Marathon (Rheem) rates 4.2 out of 5 in our premium-tier water heater assessment. The scoring reflects build quality, parts availability on Long Island, warranty terms, and how the equipment holds up in the homes we service. Best for: Best lifetime tank warranty. Reviews are only half the picture — sizing and installation quality drive most of the failures we get called to.
This is Home+ Air & Heat's own editorial assessment as an insured, EPA 608-certified installing contractor, not an average of customer star ratings.
What reviewers and installers praise
- • Lifetime tank warranty — never rusts
- • Polybutene tank construction
- • Excellent insulation
- • No anode rod maintenance
Complaints worth knowing before you buy
- • Electric only
- • Higher upfront cost
- • Heavy unit
- • No gas models
How to judge a Marathon (Rheem) quote
- • Ask for the exact model numbers and the load calculation behind the sizing.
- • Confirm who registers the warranty and what labor coverage is included, in writing.
- • Check that the installer is qualified for the specific line, not just the brand.
- • Compare total installed scope — venting and electrical — not just equipment price.
Expert Review: Marathon (Rheem)
First-hand experience from our Nassau County water heater installation team.
Marathon (Rheem) Water Heaters: An Expert Review by Home+ Air & Heat
Our Field Experience in Nassau County
Here at Home+ Air & Heat, we’ve been installing water heaters across Jericho and wider Nassau County for years, and Marathon (Rheem) units are a product we know well. We've seen firsthand how these premium electric tank water heaters perform in the varied homes across Long Island. Our technicians appreciate their robust build and the straightforward installation process, despite their heavier weight compared to some other brands. The most common feedback we get from homeowners after installation is their satisfaction with consistent hot water and, over time, the peace of mind knowing they won't be dealing with tank corrosion.
Handling Long Island's Hard Water and Coastal Conditions
Long Island’s water, particularly in Nassau County, is known for being hard, which can be a significant challenge for conventional water heaters. This is where Marathon truly shines. Their unique polybutene tank construction means there
Blake Ruwali
EPA 608-Certified HVAC Technician
Pros
- Lifetime tank warranty — never rusts
- Polybutene tank construction
- Excellent insulation
- No anode rod maintenance
Cons
- Electric only
- Higher upfront cost
- Heavy unit
- No gas models
Marathon (Rheem) Key Specifications
UEF Range
0.9–0.95
Price (Installed)
$1,500–$3,000
Tank Warranty
Lifetime
Types Available
1
Top Marathon (Rheem) Water Heater Models
Model 1
Model 2
Model 3
Marathon (Rheem) Warranty Coverage
Tank
Lifetime
Parts
Lifetime
Labor
N/A
Warranty terms require professional installation and product registration. We handle all warranty registration for our customers.
Marathon (Rheem) Water Heater Cost in 2026
A Marathon (Rheem) water heater costs $1,500–$3,000 installed on Long Island, depending on the fuel type, capacity, venting, and code-required upgrades. That range covers the equipment, standard installation labor, and haul-away of the old unit — exact pricing is confirmed in writing after a short in-home assessment.
Marathon (Rheem) Installed Range
$1,500–$3,000
Premium tier ($$$) • Lifetime tank warranty
What moves the price:
- Fuel type and capacity (tank vs. tankless vs. heat pump)
- Venting, gas-line, or electrical upgrades required by code
- Expansion tank and haul-away scope
- Heat pump models may qualify for PSEG-LI instant rebates
Prices reflect typical Nassau County installations including labor and materials. Federal 25C ended after 2025; current heat pump water-heater incentives vary by model and program.
Marathon (Rheem) Water Heater Cost by Size (40, 50 & 75 Gallon)
A standard 40-gallon tank replacement starts at $3,700 installed on Long Island, a 50-gallon tank from $4,100, and a 75-gallon tank from $5,900. Capacity is only part of the answer — the first-hour rating, fuel type, venting and code-required upgrades decide the final written price.
| Size / type | Fits | Installed |
|---|---|---|
| 40-gallon gas tank | 1–3 people, 1–2 bathsBaseline like-for-like replacement including haul-away | From $3,700 |
| 50-gallon gas tank | 3–4 people, 2 bathsMost common upsize when the old 40 ran short on back-to-back showers | From $4,100 |
| 75-gallon gas tank | 5+ people, 3+ baths or a soaking tubOften needs venting and gas-line review before it can be approved | From $5,900 |
| 50-gallon electric tank | 3–4 people, no gas serviceElectrical circuit and breaker capacity confirmed on site | From $3,400 |
| Heat pump water heater | Basement or utility-space installsPSEG-LI instant rebate of $1,000–$1,200 applies to qualifying models | From $4,900 |
| Tankless (gas) | Continuous hot water, space savingsConversion project: venting, gas capacity, condensate and water quality | From $6,500 |
What size water heater do I need?
- Match the first-hour rating to your busiest hour, not just the gallon number on the label
- Add capacity if showers run back-to-back or a soaking tub is in use
- Tankless is sized by peak flow and incoming water temperature, not gallons
- Heat pump models need clearance and air volume around the unit
Marathon (Rheem) Brand History
Founded in 1925
Marathon (Rheem) has been manufacturing water heaters for over 101 years. Proudly American-made.
Part of Rheem Manufacturing
Rheem Manufacturing focuses on the Marathon (Rheem) brand for residential water heaters.
Who Should Choose Marathon (Rheem)?
Large Families
Marathon (Rheem) tankless units provide unlimited hot water for households of 4+.
Small Homes
Marathon (Rheem)'s smaller tank models fit tight utility closets in older Long Island homes.
Energy Savings
Marathon (Rheem)'s high-efficiency models help cut energy bills with UEF ratings up to 0.95.
Ready for a Marathon (Rheem) Water Heater?
Get a free, no-pressure quote from our certified technicians who install Marathon (Rheem) water heaters regularly.
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Get a Marathon (Rheem) Quote
Free estimates • Same-day service available
The brand matters less than the installer
A great water heater installer on Long Island will outperform a premium unit installed poorly. Use the verification checklist and three-estimate worksheet before you sign anything.
Open the contractor comparison guideMarathon (Rheem) Heater Types
🔥 Water Heater Buying Guide
Tank vs tankless vs heat pump — find the right water heater for your Nassau County home.
Read the Guide →About This Review
Amy Milani
Writer
Blake Ruwali
EPA 608-Certified Reviewer
Updated:
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