As a tankless water heater can last up to 20 years--most storage-type water heaters only last 10 to 15--routine maintenance is key to extending the heater's life and savings. Most installers recommend that a tankless heater is flushed of impurities every six months to two years.
A flush kit can be obtained from a certified technician, or a person may choose to do it himself, depending on his or her needs. The instruction manual that comes with a tankless heater is an invaluable tool that allows a user to upkeep and maintain a water heater on his own---so you are best off checking the manual for flushing instructions beforehand.
Flushing the water heater with CLR or vinegar returns the water heater to a sediment-free, almost brand new state by removing any particulate buildup throughout the system. Flushing is also extremely inexpensive when done on one's own compared with the $100 to $200 cost of repair.
Minimum Flow Rates
Every water heater owner should note the minimum flow rate of his heater. Low flow rates can result in difficultly using multiple applications of a heater at one time---flushing toilets while showering, for instance, can cause heating and flow issues.
Routine maintenance of a water heater should include an analysis of the flow rating of the heater to determine whether the minimum is right for a home or building. For a tankless water heater to keep working as best it possibly can, the showerheads and faucets should be checked often for residue and buildup that impedes flow.
The heater's inlet filter ought to be the first system checked when a problem occurs, as sediment that slows or stops the filter affects flow to the entire system.
Venting of the Heater
When a water heater is allowed to build condensation and pressure, it can fail easily. Therefore, venting of a water heater is an important step toward ensuring its lifetime viability.
Condensation that enters into a mix damages the lifespan of a water heater; allowing carbon monoxide to build up inside can at worst be fatal. Venting in a tankless heater goes out of a wall or up through the roof of a home.
When installing a water heater, venting should always be kept to a minimum length and should be checked regularly for leaks or blockages. Issues with water heaters are often resolved by doing a routine check of the venting system, but failing to do so can result in negative effects for a whole building.