Wednesday, January 29, 2014

Standard Tank Water Heaters vs On Demand Tankless Water Heaters




One of the most common questions I hear today when replacing a water heater is - should I replace my Standard Tank Water Heater with an On Demand Tankless Water Heater?

Let me first say that water heaters account for 18% of annual energy consumption in American homes. It takes a lot of energy to heat water as anyone waiting to boil a gallon of water on a stove can attest.

Now let’s look at some of the differences between the types of water heaters so you can make an informed decision on what best fits your situation.

Standard water heaters with a tank that vents into a chimney and electric water heaters represent our least efficient heaters. But they have been, by far, the work horses of the industry.

Typically, after Simmons Plumbing and Heating installs a water heater, you may not need to call us again for any hot water related issue until the useful life of your water heater is over. Initially, it is less expensive to install a standard water heater and most tanks come with a six year warranty and you can purchase an option for up to ten years.

So why would you want replace your dependable Standard Water Heater it with an On Demand Tankless Water Heater?

It typically does cost more to change out a tank with an On Demand Water Heater. Gas piping will almost certainly need to be changed to accommodate the input demands of the newer equipment. Typical gas inputs of a 40 or 50 gallon tank on a Standard Water Heater would be 40,000 BTU’s per hour. The up fit gas change for and On Demand Water Heater would require a need for piping to supply 180,000 to 195,000 BTU’s per hour. The reason for this is because to have a continuous flow (3 gallons a minute through the heat exchanger) of hot water more gas is needed to change incoming the water temperatures of 45 degrees to 130 degrees. In the end, however, switching to a Tankless Water Heater will save you money.

I know this just doesn’t sound right, how can putting more gas in be cheaper to run?

Efficiency, Efficiency, Efficiency, heat is not lost during down time to the chimney with an On Demand Water Heater. With a Standard Water Heater heat loss through the chimney ultimately makes a big sucking sound on your wallet. Heat is also lost through other outward forces like the walls of the tank itself, the  pilots. Let's not forget about that mass of water in the tank that continuously needs to be monitored and heated, so it remains at 125-130 degrees 24/7 for when you need it. An On Demand Tankless Water Heater does none of these things. If you’re not using hot water it simply does not come on.

So the good news is your can cut your current energy use of your home’s hot water by 25 to 30% .  That is a substantial overall savings on your utility bill.

In addition you now have a water heater that the family shares that will provide hot water to the last user as well as the first. Wow what a concept.

However, there are some things to consider when using an On Demand Water Heater.

For one, they tend to extend the pre-run time needed to get the hot water to the appliance, so there will be some wasted water down the drain, so to speak.

With most installs the Exhaust and supply air piping will exit/enter the home on one of your side walls of the home and some of this will be seen. It can be painted to match the home, helping blend in.

The exhaust from your Tankless Water Heater is mostly water vapor, a byproduct of burnt natural or LP gas, in winter months you will see a fog like haze.

Warranties vary but Simmons Plumbing and Heating uses a brand that provides a manufacture’s warranty to our customers. It includes coverage on parts for two years and a 15 year heat exchanger warranty (against leaks) with a full water heater replacement should a leak occur within those first fifteen years.

Water conditions should be considered when deciding on an On Demand Water Heater. And as with any major home appliance some maintenance is required. Mineral deposits, in particular should be addressed. 

Financial incentives are also available for most customers that have natural gas. New Hampshire customers have monies available for both natural and LP gases.

One final  note concerning tank type water heaters, both electric and gas.  Starting in 2015, they are slated for big changes in required efficiency standards. This will narrow the gap between them and On Demand Water Heaters, but there will still be a wide margin for cleaner exhaust, better operational costs and endless hot water, with the advantage going to the On Demand Water Heaters.

Lastly let me say that both types of water heaters will be with us for a long time to come. So it comes down to whether you want to save  money now or later.









 

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