Frequently Asked Questions
Q. "If these units don't have a tank, how do they know when to turn on?"
A. These tankless water heaters have a flow switch built into them. When you turn on the hot side of a faucet the water begins moving. Once the water is traveling at minimum flow rate for the heater, the flow switch will turn on the gas.
Q. "Why can't I install the TK-510U-E myself?"
A. Improper installation of the TK-510U-E could create carbon monoxide gas and other dangerous gases. Installation of this unit by persons other than professionally trained technicians voids the warranty.
Q. "What's the first hour rating of this water heater?"
A. Traditional tank water heaters have a first hour rating which is determined by the amount of hot water the heater can produce in an hour when starting with a full tank of hot water. As tankless water heaters do not start with a tank of hot water, they don't really have a first hour rating the same way a tank water heater does. Instead, tankless water heaters have a gallons per hour rating, which is determined by how many gallons per hour the tankless water heater can produce when raising the incoming water temperature a specified amount.
Q. "Your products specify the 'temp. rise' based on the GPM flow; what do you mean by this?"
A. Temperature rise is the amount the heater raises the temperature of the incoming water, based on the flow rate shown of that water.
Q. "It sometimes drops below freezing where I live. Can I still install a Takagi tankless water heater outside?"
A. Takagi gas tankless water heaters are designed to be installed outdoors only in mild temperate climates. The factory-installed freeze protection device is rated for temperatures down to 5°F in a wind-free environment, so wind-chill factors must be taken into account when choosing whether or not to install a Takagi tankless water heater outdoors. If you are unsure if temperatures at your planned installation would work for an outdoor tankless water heater, we strongly recommend consulting with a trusted local professional.
Q. "What do I need to install these Takagi tankless water heaters outdoors?
A. Outdoor-only Takagi tankless water heaters, such as the TK-510U-E, the TK-310U-E or the TK-110U-E, require no additional venting components. Units that can be installed either indoors or outdoors, are designed to need only the addition of an outdoor vent cap or properly vented recess box in order to function in an outdoor installation. Please note that Takagi tankless water heaters, like most brands of water heaters, are designed to be installed outdoors only in mild temperate climates. As always, please consult with your installer or another trusted professional before installation.