Tankless water heaters are very popular, and sellers are pushing the cost savings (I’ve seen numbers that range from 10% savings all the way up to 60%!) as justification for these expensive units. But before you run to your computer and order one, take a look at the pros and cons to decide objectively if you really need to shell out your hard-earned money. You may be able to achieve the same objectives with a less-expensive system.
Household hot water heaters come in two basic flavors: the traditional storage tank unit that typically holds about 50 gallons of water and keeps it hot all the time, and the so-called tankless systems (also called instant, demand, or point-of-use systems). The latter doesn’t have a big space-eating tank. Instead, it has a system of heaters in a wall-mounted unit Best propane tankless that are activated when water starts to flow through the pipes. Then it jumps into action and heats the water very quickly; until then, though, you aren’t spending money keeping unused water hot.
This feature, advertised as “eliminating stand-by losses,” is what is claimed to be the big money saver with tankless systems. Both flavors come in electric, gas, and propane models, and the power source you’ll be using is an important factor in evaluating water heaters.
There are several important questions in assessing what type of water heater is best for your home. The answers will quickly tell you what you want to know.
First, how much of the house is to be supplied by this water heater? If the answer is that this is to be a whole-house water heater, both tankless and energy-efficient tank units could fit the bill. Costs are often comparable between popular tankless models and higher-end efficient tank systems. That means, both are more expensive that low- or mid-quality tank units.
Second, is this going into a new house under construction, or are you just replacing a heater in an existing home? Depending on how your plumbing is set up, and the power source for your heater, the costs of installing a tankless unit into an existing structure could be prohibitive. Installing a tankless system can run 2 to 4 times the cost of a tank unit. If you want to install an electric tankless system, you could be required to upgrade your electric panel and wiring to accommodate the huge power pull electric units have when they get a hot water call. If you are installing a gas or propane system, you will need to ensure that you have the proper venting, airflow, and spacing requirements that the manufacturer and local codes specify. This kind of adaptation can be expensive. It is much more economical to install a tankless system when a house is being built. An added benefit is that you could install a whole-house radiant hot water heating system, and have the hot water heater as a nice little bonus since water is being heated anyway and there’s little additional cost.
Third,What energy source will power the heater? In some areas electrical power is very expensive relative to gas. If you have natural gas piped into your house already, this makes a gas tankless system the way to go, as long as the venting/airflow modifications don’t get out of hand. If you now have an all-electric house and would need to have gas piping brought in, this conversion could wipe any cost savings out for years to come. You would only consider this modification if you were to stay in the house long enough to realize those savings, which means quite a few years. If you’re going to be selling your house in a few years (say less than 5), then this conversion doesn’t make a lot of financial sense. Electric tankless heaters typically don’t have the heating power that the gas units do. For example, a gas unit can heat up about 5 gallons per minute, while an electric unit usually runs at about 3. If you have a houseful of hot shower nuts, you’ll want the higher capacity unit. Of course, these are more expensive to buy as well as operate. Operating costs for electric units typically save 10-20% of total home energy costs, while gas units can save 20-40%. While this sounds good, calculate what your current energy costs are now, and then calculate what the savings would be in dollars for the new unit. Depending on the cost of energy, your big savings may only be a couple of hundred dollars a year.