Sizing a Tankless Hot Water Heater

Posted on May 6, 2009 | 0 comments

The largest difference between a tankless and a conventional tank type system is that, while a tank can supply a large amount of hot water for a short period, a tankless water heater provides a smaller amount limitlessly. Thus with a tank type water heater you can run all your taps and showers and have all the hot water you want…. Well until the tank runs dry, and that shouldn’t take long. With the tankless system you can open all the taps to the capacity of the tankless, and have hot water for as long as you want. Yet if the system was undersized or sees demand beyond its designed capacity, your water will only be lukewarm.

In fact that’s really about the only thing that can go wrong on a tankless water heater, and realistically its not even the fault of the heater. This usually occurs when customers don’t take the time to really understand how a tankless hot water system works. It’s also cause by people trying to get the best deal or cheaping out and having a dealer install a smaller unit.

A tankless water heater has a certain capacity that has to be carefully calibrated to make sure that it can handle the highest load that a house can produce. A smaller sized tank may be able to handle only a gallon of hot water a minute (about one shower). If you have a larger family or home that has multiple showers you will need a much larger system.

Any contractor trained in tankless hot water heater installation will be able to give your situation and home the best advice on which model to choose.