Review of condensing and non-condensing State tankless water heaters. Find the models with the high thermal efficiency and flow rate. Which tankless models are saving you the most money?
State tankless water heaters are built for potable water heating in residential and commercial applications and hydronic heating. All of them are Energy Star approved models, which means that the energy factor is 0.82 or higher. Models with the most advanced features, highest EF factor and hot water flow are condensing heaters. Others are known as non-condensing. This review covers the second group.
All residential water heaters can be grouped in several categories: 110, 310, 510, 320 and 520.
State tankless water heaters from the 110 series are the smallest units, and since the capacity is enough for one to two showers, they are ideal for apartments, condos and smaller houses.
310 and 320 series are good for two and three showers, 510 for two and four and 520 for three and four showers. The smaller number (of showers) shows what one unit can handle in cooler climates while the higher number applies for warmer regions, where the ground water has the higher temperature.
All State tankless models are built for an indoor and outdoor installation, and factory built to work on natural gas and easily converted to propane. The choice is yours. Keep in mind that the warranty for all models is 12 years on the heat exchangers and 5 years on other elements. Proper plumbing installation, for example, maintainance and winterizing are just some of the factors that needs to be taken care properly for the tankless longevity.
State tankless water heaters GTS-110 and GTS-310 are similar models. The only difference is in the power they provide and maximum water flow. The smaller units come in the capacity of 6.6 gallons per minute and gas input in a range from 19,500 to 140,000 Btu, while the models from 310 series have a capacity of 8,0 GPM and gas input from 11,000 to 190,000 Btu.
Models from the GTS-510 group have the highest water flow of 10 GPM of all non-condensing models, and gas input from 11,000 to 199,000 Btu. These are the strongest units from this group, especially thanks to the thicker, heavy-duty heat exchanger, which ensures longer life. These models come with the higher capacity, but if more hot water is needed, up to four of these models can be linked.
The neat feature, again present on all State tankless water heaters is a remote control, which is used not only to monitor the temperature but to get notification when there is a problem with the heater. The LCD display shows the current temperature of the outgoing hot water and when the problem occurs, the error codes flashes followed by the alarm.
Underneath the display, there are several buttons, which help you to turn the unit ON or OFF, change the temperature, get the information about the water temperature and flow rate and set the time.
Condensing tankless water heaters are the most advanced on the market. State condensing models have two heat exchangers, the main one which is usually made of copper, where most of the heat transfer occurs, and the second one, stainless steel, which is used to increase the temperature of the incoming cold water. Thanks to the SS material the corrosion resistance is greater.
Non-condensing models have one heat exchanger, which is made of copper and these models are cheaper to buy, but condensing are better performing; the energy factor is 0.91, vs. 0.82 .
Non-condensing water heaters must use Category III Stainless Steel venting system while condensing, due to the lower temperature of the exhaust gases, can use PVC vents. Great thing with the tankless water heaters is flexibility when installing the vents, since they can run horizontally or vertically. As the units use the power vent for directing gases out, maximum length is up to 50 feet.
State tankless water heaters are ideal solution for those who are looking for on-demand water heating, to save a floor space and want a peace of mind when referring to the capacity. State heaters are similar to tankless models from AO Smith and the great thing is the variety and service network. With several safety features, such as built-in freeze protection, overheat sensor or flame detection, that protects the unit and the user, State heaters are also environment-friendly as their burners are low NOx burners.
Picture - courtesy of State Industries