We're having a tankless hot water heater installed in our new house. These systems heat the water only when needed, rather than keeping a supply of water heated all the time. We used this sort of system when we lived in Vienna, Austria, and it worked fine for us.
The diagram below shows how the system works.
1 - Exhaust
2 - Heat exchanger
3 - Burner
4 - Fan
5 - Control panel
6 - Flow sensor
7 - Hot water to faucet
8 - Gas supply
9 - Cold water coming in
10 - Cold water to faucet
 |
| Plumbing for tankless hot water heater in in storage room downstairs |
 |
| The Navien tankless system is much smaller than a hot water heater |
 |
| The large diameter pipes above the unit are intake and exhaust pipes |
 |
| The intake and exhaust pipes for the Navien exit the house under the deck. A chase has been built to hide these pipes. |
 |
| The exhaust pipe travels along the back wall of the garage up to the roof |
 |
| Bottom of the Navien unit showing water inlets and outlets, as well as circulation inlet, and gas inlet. |
 |
| Navien energy guide |
 |
| Navien cover has been removed to permit testing |
 |
| Closeup of insides of Navien unit |
 |
| Mother Board -- Error codes show on display (showing 8888) |
