Gas Line Sizing For Gas Tankless
Water Heaters
Check to make sure your gas line is sized properly. Tankless
water heaters draw many more BTU's than a tank water heater, so
you will want to make sure your gas line is of the proper size
and the distance the gas line is run is not too long, so the
unit will function properly. Below are tables that show
the maximum gas line run by diameter for natural gas, propane
(LP) with black iron pipe and propane (LP) with copper tubing.
If any other applications are sharing the line or for more
specific information, please consult the National Code Fuel Chart.
Maximum length of black iron pipe run for Natural Gas
Model |
Nominal Iron Pipe Size (diameter) |
|
3/8" |
1/2" |
3/4" |
1" |
| Bosch 38B |
20 ft |
80 ft |
|
|
| Bosch 1000P |
5 ft |
20 ft |
100 ft |
|
Bosch 1600P/125B,
Bosch 1600H/125HX |
|
10 ft |
40 ft |
150 ft |
Bosch 1600F/125FX |
|
10 ft |
40 ft |
125 ft |
| Rheem RTG-53 |
Not recommended |
30 ft |
100 ft |
| Bosch 2400E, 2400EO/250SX |
Not recommended |
20 ft |
70 ft |
| Rheem RTG-74, Rheem GT-199 |
Not recommended |
15 ft |
55 ft |
Important Factors to Consider
Gas Venting Requirements
Gas Line Sizing Requirements
Gas Combustion Air Requirements
|
