Our goal is to provide visitors with excellent plumbing how to's and other great plumbing-related articles.
Kitchen related articles Bathroom related articles Commercial related articles Misc articles Favorite links

Tankless Water Heater Information

Tankless Water Heater FAQ
Q. "Will an instantaneous water heater save me money on my utility bills?"
A. Yes, in most applications you will see a savings. There are some variables that could reduce the amount you save. One example is you will not run out of hot water, so longer showers could cut into your savings. Also, the cost of electricity, propane and natural gas in your area will affect the amount of money saved. The higher the cost for the energy type used to heat your water, the quicker you will recover the higher initial cost of installing a tankless versus tank style water heater.

Q. "What are the positives & negatives with tankless water heaters?"
+ You will never run out of hot water. "You want an hour long shower? no problem!"
+ Electric units can be installed at the point of use.
+ You're not paying energy costs to heat water 24 hours a day.
+ They're easy to install.
+ Many electric units don't require a T&P valve. (No tank!)
+ Installing a tankless water heater will indeed be a bonus to the environment.

- They all need a minimum flow rate & pressure to turn on.
- The faster water flows through them, the lower the temperature rise. So, if you expect to take a shower while the clothes washer is running, you will need to select a unit sized to your hot water flow requirements. (Gas units handle this a little better than electric models)
- Electric units need heavy gauge wire. Example: the 9.5kw must have 8ga wire and a 50amp breaker.
- Gas units need a much larger, special flue pipe and larger gas supply than a conventional water heater.
- At times they can produce very hot water. It's easier to get scalded.
- Gas units are more complicated than a conventional water heater.
- With some brands, parts are hard to find (not a negative if you originally purchase from us, as we like to carry parts for the units that we sell).

Q. "If the units don't have a tank, how do they know when to turn on?"
A. The tankless water heaters have a flow switch built into them. When you turn on (open) the hot side of a faucet the water then moves (travels). Once the water is traveling at 3/4 of a gallon per minute or faster most tankless water heater switches will then turn on the gas or electricity.

Q. "What's the difference between a conventional flue and a direct vent?"
A. A conventional flue is what most people are familiar with. It typically consists of a double-wall flue pipe going from the top of the heater through the roof, venting outside. The fixture draws its combustion air from the space around it (utility room, garage, hallway, etc.). A direct-vent unit on the other hand, both vents and draws its combustion air through a specially designed pipe from the outside via an adjacent wall.

Q. "Can I install tankless water heaters in my attic?"
A. Without seeing all of your plumbing piping, etc. it is difficult for us to answer with a straight "yes" or "no." One must be sure that a possible water siphoning condition can not be created as tankless water heaters should not have air in the lines. Water siphoning out of any brand of tankless water heater might damage the heater when there is no water (or not enough water) in the lines.

Q. "Is it possible to drain a tankless water heater to prevent freeze damage when not in use?"
A. Yes on most brands (best to check first though with the supplier). Simply drain both lines 'to' and 'from' the unit. As long as there are no check valves in the way, that should drain the water from the unit. To guarantee that there is no water in the unit, we recommend two drain valves - one before and one after the unit - as well as blowing air through the water line.

Q. "Can I replace my existing tank type water heater with a tankless water heater?"
A. Yes, but there are specific requirements that will need to be addressed. Gas units will require a larger, special vent pipe and a larger gas supply line that not only will supply the water heater, but all other appliances on that gas pipe run. Electric units will require larger gauge wire and breakers than most tank type water heaters.

How Tankless Water Heaters Work

Tankless Process

Tankless Water Heater Recirculation

Tankless Process

Multi-Unit Tankless Water Heater Recirculation

Tankless Process