Operating Guide
6- SIZING GUIDE
Please use the chart below to see how many gallons per minute your tankless water heater can produce with your 
incoming water temperature. The gallons per minute is calculated assuming 105°F outlet temperature.   
Incoming 
Water 
Temperature 
EEM24008 
EEM24011 
EEM24013 
EEM24018 
EEM24024 
EEM24027 
EEM24036 
40°F 
0.8 
1.2 
1.4 
1.9 
2.5 
2.8 
3.8 
45°F 
0.9 
1.3 
1.5 
2.0 
2.7 
3.1 
4.1 
50°F 
1.0 
1.4 
1.6 
2.2 
3.0 
3.4 
4.5 
55°F 
1.1 
1.5 
1.8 
2.5 
3.3 
3.7 
4.9 
60°F 
1.2 
1.7 
2.0 
2.7 
3.6 
4.1 
5.5 
65°F 
1.4 
1.9 
2.2 
3.1 
4.1 
4.6 
6.1 
70°F 
1.6 
2.2 
2.5 
3.5 
4.7 
5.3 
7.0 
75°F 
1.8 
2.5 
3.0 
4.1 
5.5 
6.1 
8.2 
80°F 
2.2 
3.0 
3.6 
4.9 
6.6 
7.4 
9.8 
(Gallons per Minute) 
FLOW RESTRICTOR – OPTIONAL 
In order to ensure the optimal temperature output and overall performance of your tankless water heater you may 
require a flow restrictor. These flow restrictors are installed on the outlet connection of your tankless water heater and 
limit the maximum volume coming out of your unit to a specified flow rate to prevent the exit temperature from 
becoming too cool. To learn more about flow restrictors or find out how to purchase one for your tankless water heater 
visit us online at Eemax.com or contact us at 1-800-543-6163.  
Steps for Choosing a Flow Restrictor 
1.
Find your model in the chart on the left 
2.
Choose the column with the inlet water temperature closest to your geographical location 
3.
Take the GPM or gallons per minute you find and match it with the corresponding flow restrictor on the right 
*Selection based on inlet temperature above and outlet temperature of 105°F
Eemax Part Number 
Maximum Flow Rate 
Connection Size 
EX0063-1.0 IFR 
1.0 GPM 
1/2" Compression 
EX0063-1.5 IFR 
1.5 GPM 
1/2" Compression 
EX0063-2.0 IFR 
2.0 GPM 
1/2" Compression 
EX0064-2.0 IFR 
2.0 GPM 
3/4" NPT 
EX0064-3.0 IFR 
3.0 GPM 
3/4" NPT 
EX0064-4.0 IFR 
4.0 GPM 
3/4" NPT 
EX0064-5.0 IFR 
5.0 GPM 
3/4" NPT 
Inlet Water Temperature 
40°F 
50°F 
60°F 
70°F 
EEM24008 
1.0 
1.0 
1.0 
1.5 
EEM24011 
1.0 
1.0 
1.5 
2.0 
EEM24013 
1.0 
1.5 
2.0 
2.0 
EEM24018 
2.0 
2.0 
2.0 
3.0 
EEM24024 
2.0 
2.0 
3.0 
4.0 
EEM24027 
2.0 
3.0 
4.0 
5.0 
EEM24036 
3.0 
4.0 
5.0 
5.0 










