Some truths and myths about Tankless Water heaters
You may be aware that there has recently been a lot of talk about tankless water heaters as the optimal choice for homeowners instead of the conventional water heater. Because of the advertising for this product, it naturally raises a lot of questions and requests for this product.
Let me start by making a few things clear about tankless water heaters. Tankless water heaters are not a new product, but they are relatively new to the USA. They have been used in Europe for at least 35 years or longer. We often get questions and calls from customers asking us to advise them on what water heating system to choose for their homes or businesses because they have heard that tankless water heaters are the better choice. Often, I will get a call from a customer asking for a price for a particular brand of tank less water heater. My first question is to ask why the customer wants a tankless water heater because the product may not be right for them. Many are surprised that I would state this because they have been told by a friend, co-worker, relative, etc. that the tankless water heater is the answer to all of their hot water needs and is extremely efficient. This is where my teaching background comes into play. Let me explain the good, bad and limitations of almost every brand of tankless water heater.
THE GOOD -
1. They are a wall hung water heater and do not take up much space.
2. They make hot water efficiently.
3. They make hot water on demand instead of storing hot water in a tank.
THE BAD –
1. The venting of these heaters can get very expensive if you are not on an outside wall. The stainless steel flue pipe and fittings are special to each manufacturer and costs can be very costly.
2. They can only produce a given amount of hot water which can be many times less than what you need in your home.
3. They have no reserve tank when there is more than one use of hot water in your home at the same time.
4. When you exceed the gpm (gallons per minute) capacity of the heater, guess what, everyone needing hot water gets a reduced amount to use and no one is happy at that point.
5. They lime up (develop mineral deposits) inside the narrow tubes after a few years of use. The copper tubes inside begin to lime up and restrict the passage way which in turn reduces the amount of hot water it produces and increases the cost of producing the hot water because the flames have to heat through the ever growing mineral deposits that adhere to the copper tubing.
6. The tubes eventually plug up and you need to delime the heat exchanger, replace the heat exchanger or the entire device, eventually. Efficiency has fallen off dramatically when the minerals start to build up and the rate of mineral buildup increases dramatically once the process starts.
Now, let me clarify that a tankless heater has its purpose and uses. You may only want a small amount of hot water in a location that is far away from the central heating plant. Since these tankless heaters often have a zero clearance to combustible materials, they can easily go into a closet area and serve a single bath. However, that still does not prevent the minerals from plugging the copper waterways. If the usage is low and the demand is controlled, these products generally perform as advertised.
On the other hand, if you live in a home with growing children or teenagers and the hot water usage is hard to calculate or you already know that you have higher hot water demand, then it is time to look at some serious options. Did you know that the conventional tank type water heater technology is such that you can produce hot water at 96% efficiency which is higher than most tankless water heaters? Also, the tank is super insulated and will not lose the btu’s stored in the hot water very easily. If efficiency is what you need, tankless water heater are not necessarily the best option. If quantity of hot water is what you need, tankless water heaters may not do the trick for the price paid, if the requirements are large. You can produce the hot water that you experience with a tank style water heater by using tankless water heaters, but you may be installing two or more tanks in parallel or series in order to get your hot water needs satisfied and then the price goes up dramatically. This is seldom mentioned in advertisements or from companies that do these installations.
Keep in mind that a tank type heater has stored hot water available instantly and you can also get several shower or baths taken simultaneously where you may not get that from a tankless heater without having one large or several heaters tied together. If you are looking at cost (and most people are) we recommend that you look at the high or ultra high efficiency water heaters on the market today. And as a bonus to using these heaters, they may qualify for the Federal Tax credit of up to $1,500 in addition to giving you a large amount of hot water at a very reasonable price.
I have touched on the basics of tankless vs. tank type water heaters but there is much more to discuss. Please give me a call and I can help you size the tankless heater if you desire or I will offer you some options and give you the pros and cons for each. Our advice is free, so give me a call and let’s chat.
Tom D’Agostino, Service Manager
Kimmel Mechanical, Inc.
Tel # Denver 303-800-3781 or Summit and Eagle County 970.328.6001