Water Heater Rebate 

About Water Heating | Download  Water Heater Coupon (PDF)

Heating water is a large portion of a household’s energy consumption. Approximately 14% of a utility bill is spent on the energy produced by a home’s water heater. For most homes with electric hot water storage tanks, heating water ranks second as the home's biggest energy consumer.

PenLight’s Water Heater Rebate:

PenLight offers a $50 rebate for high efficiency water heaters that meet specific performance specifications. The requirements to receive this rebate are:

  • Submit a completed Water Heater Rebate Form (for qualifying models purchased through outside retailers)
  • Legible copy of purchase receipt which includes brand name and model number

* Heat Pump Water Heaters do not qualify 

Marathon Hot Water Heaters

Marathon Water Heaters offer a lifetime warranty for as long as you own your home. The Marathon unit uses a thick layer of Envirofoam, which is completely CFC and HCFC free, to make the unit the most energy efficient model, size for size, of any available today. The Marathon has a tough, durable polyethylene outer jacket, making it lightweight but resistant to dents and scratches. Since it uses a non-metallic tank, the Marathon unit does not have an anode rod, eliminating any odor problems. It also features a recessed drain valve and a "bowled shaped" self-cleaning tank. If you purchase a Marathon Water Heater through PenLight, we will provide and complete the $50 rebate form at the time of purchase. Marathon Water Heaters are available in 30, 40, 50, 75, 85, and 105 gallon tanks. If you are interested in a Marathon unit please call (253) 857-5950 for questions and pricing.

Frequently Asked Questions


How much more is the Marathon than a conventional water heater?

The 40 or 50 gallon Marathon will cost approximately 2 times more than a basic steel water heater on the smaller sizes and the larger 75 to 105 gallon units will be the same or less than steel water heaters. That is not a real comparison, however, as you are comparing a lifetime warranty product that is super-insulated against a 5 or 6 year warranty product with minimal insulation. Installation for the Marathon is usually easier than for steel units.


Is it worth more than a conventional water heater?

Yes. The Marathon will save you energy year after year and after five years it won’t have to be replaced. With the Marathon, you won’t have to pay for installation costs in five years when other models tend to breakdown. The other thing people often overlook is the damage to their floor and belongings when their cheaper water heater fails.


Why should I bother? My last water heater lasted 22 years.

That’s impressive but not uncommon for older water heaters. Older water heaters had much thicker steel and more porcelain than the new units. Because manufacturers have cut so many costs from the manufacturing process, most steel water heaters made today will not last much longer than their warranty.


If I can’t afford it right now what can I do?

No one makes it easier to own the world’s best water heater than Peninsula Light Company. With our easy terms, you can start realizing your energy savings right away and use those to offset the cost:

  • We offer a $50 mail in rebate on the Marathon to keep the cost to our members low.
  • You can pay by cash, check or a credit card.
  • We also offer 90 days same as cash financing for the Marathon. You can have this amount added to your electric bill with no interest!

Can I install it myself?

We do recommend you have a professional do the installation, but if you are experienced, you can. The Marathon comes with a clear installation guide – just note that there are a couple of small but important differences between installing the Marathon and a standard tank. You will quickly see it is actually easier to install than a regular water heater.


Do you offer installation?

No, we do not. However, we can refer you to a local contractor we have worked with on other Peninsula Light programs.


What is the benefit of a conventional water heater over a tankless water heater?

Conventional water heaters have many advantages over tankless. ‘Click Here’ (pdf) to learn more about tankless water heaters.


I am building a new house, wouldn’t gas be cheaper?

Not necessarily. Although gas may be slightly cheaper, gas water heaters are more expensive than electric units and the venting now required for safety can be quite expensive. Electric water heaters are nearly 100% efficient, as all of the heat generated stays in the unit. Gas water heaters have a tendency to allow heat to escape. Also, the Marathon is like a Thermos in that it keeps the water hot once you have heated it. It’s the most efficient water heater made. Many people are now building tighter, more efficient homes and indoor air quality is becoming a concern. Any fossil fuel water heater can be a problem with carbon monoxide and other pollutants needing to be vented. You can eliminate this issue entirely, however, with the energy efficient, electric Marathon.


What size do I need?

The Marathon comes in several different sizes – the 15, 20, 30, 40, 50, 75, 85 and 105 gallon models. The size of the water heater your home will need is dependent on the number of people in your household and how much hot water is used. Here are some approximate tank volumes that are seen fit for homes within the size range: 

Household Size





Tank Volume in Gallons

30, 40, or 50

50 or 85



85 gallon or larger tanks are recommended for whirlpools and Jacuzzis.

Water Heating Maintenance

  • Repair leaky faucets promptly; a leaky faucet wastes gallons of water in a short period of time.
  • Drain a quart of water from your water tank every 3 months to remove sediment that impedes heat transfer and lowers the efficiency of your heater. The type of water tank you have determines the steps to take, so follow the manufacturer's advice.
  • Although most water heaters last 10–15 years, it's best to start shopping now for a new one if yours is more than 7 years old. Doing some research before your heater fails will enable you to select one that most appropriately meets your needs.

Ways to Conserve:

  • Lower Water Temperature. Keep your water heater thermostat set at the lowest temperature that provides you with sufficient hot water. For most households, 120°F water is fine (about midway between the “low” and “medium” setting). Each 10°F reduction in water temperature will generally save 3–5% on your water heating costs.
  • Conserve Water. Your biggest opportunity for savings is to use less hot water. A family of four each showering five minutes a day can use about 700 gallons per week. Other opportunities for limiting hot water use are by using short cycles for wash and by making sure to run full loads of dishes. Also, water-conserving showerheads and faucet aerators can cut hot water use in half.
  • Insulate Your Existing Water Heater. If your electric water heater was installed before 2004, installing an insulating jacket is one of the most effective do-it-yourself energy-saving projects, especially if your water heater is in an unheated space. The insulating jacket will reduce standby heat loss—heat lost through the walls of the tank—by 25–40%, saving 4–9% on your water heating bills. Water heater insulation jackets are widely available at minimal costs. Always follow directions carefully when installing an insulation jacket.
  • Insulate Hot Water Pipes. Insulating your hot water pipes will reduce losses as the hot water is flowing to your faucet and, more importantly, it will reduce standby losses when the tap is turned off and then back on within an hour or so. A great deal of energy and water is wasted waiting for the hot water to reach the tap. Even when pipes are insulated, the water in the pipes will eventually cool, but it stays warmer much longer than it would if the pipes weren’t insulated.
  • Purchasing a new Energy Efficient Water Heater. It is important to find a product that is suitable for your household needs. By taking a little extra time to become familiar with the Energy Guide Labels, your home can become efficient and energy savings will follow.  Click here to Learn How to Use the Energy Guide Label.


For more information, call (253) 857-5950 or email

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