Internal Whole House Natural Gas Tankless Water Heater 7.5 Gallons Per Minute with Isolation Valves
Things to consider
The Rinnai water heater works well and saves energy but there are some issues that are specific to these water heaters and I am going to tell you the whole truth.
Venting: The exhaust/combustion air vent is tested and listed for the unit and you can’t use any other vent. It uses outside air for combustion and is very safe. The direct vent sealed combustion vent allows Rinnai to be installed in bath rooms and bed rooms where traditional B-Vent water heaters cannot. There are limitations of how far away and were you can terminate the vent, check out the installation manual for that.
Hot Water: It will make endless hot water until you turn off the tap, a minute, an hour, a week. It can only supply so much at a time, depending on your cold water temperature it will only run two or three fixtures at once. It is an ‘on demand’ water heater, not an ‘instant’ water heater, hot water will take longer to arrive at the fixture than it will from a tank water heater.
Gas Supply: These water heaters use less fuel than a tank style water heater but when they want fuel, they want it now. Your tank style water heater required a gas supply of about 40,000 btu’s per hour, your Rinnai will require 180 to 199,000 btu’s per hour. Check you gas supply lines to make sure they have enough capacity for the new load or your new water heater won’t perform to its potential without upgrading the supply line.
Expect some maintenance: This is an energy saving, high tech machine with a combustion fan, pc board and electronic solenoid valves to control water and gas flow. Your water quality will also determine how often the unit will need to be flushed, generally every one or two years. Flushing is done by using a small pump to circulate a solution through the unit to dissolve calcium deposits that form inside the heat exchanger. You should flush a tank style water heater too but most people don’t. If you don’t flush your tank less water heater the efficiency will be reduced and you may get inconsistent water temperatures. In the worst case it could plug the heat exchanger or cause it to leak requiring replacement.
Finding service: This point can be a little sticky. Rinnai’s warranty isn’t affected by internet purchases but your online retailer won’t be much help. Rinnai has an online dealer locater but if you haven’t purchased the appliance from that dealer it is a little like bringing your own steak to the restaurant, they may cook it for you but they won’t guarantee the results. Be prepared to pay the service man and fight Rinnai for reimbursement or buy locally.
Hope this helps.
June 11, 2013