Flow Sensor Assembly for EcoSmart ECO 18, 21, 24, 27 and 36, plus Rheem RTEX & Eemax HomeAdvantage/ProAdvantage
This item ships with a plug connector as shown in the photos above. If you have an older style unit that connects with bare wire or terminals, then you should strip the wires on this part and connect in the following order from top to bottom: BLACK, WHITE, RED.
The genuine EcoSmart part may ship without the EcoSmart logo as shown in some photos. You may call EcoSmart tech support to verify this at 877-474-6473.
Also 100% compatible with the following heater models:
≈ iHeat/Drakken AHS27D, AHS18D, AH27, AH18
≈ Eemax HomeAdvantage HA018240, HA027240, HA036240
≈ Eemax ProAdvantage PR018240, PR027240, PR036240
≈ Eemax EEM24018, EEM24027, EEM24036 (blue color units)
≈ Rheem RTEX-18, RTEX-27, RTEX-36
≈ Rheem RETEX-18, RETEX-27, RETEX-36
≈ Richmond RMTEX-18, RMTEX-27, RMTEX-36
ECO 18, ECO 21, ECO 24, ECO 27 and ECO 36 Thermistors Troubleshooting Steps
Turn off breaker.
Unscrew cover.
Locate temperature sensors on inlet and outlet pipes. It is the nut with wires coming out of it.
Follow cable to electronic board.
Remove electronic board cover.
Disconnect from board.
Turn on breakers.
Turn on hot water tap.
Wait 3 to 5 minutes.
If water still does not heat up, further technical troubleshooting is needed. Volt meter is required.
If the water heats up, then the thermistors are bad. Just leave them disconnected (creating a bypass) until you can replace the thermistors.
EcoSmart tankless water heater technical overview
The ECO 18 is the medium sized model and carries (2) heating elements and exchangers using (2) 9 kW @ 240 Volts.
The ECO 21, ECO 24, ECO 27 and ECO 36 have the largest-sized form factor and they each use heating elements and exchangers. The ECO 21 uses three 7 kW elements running at 240 Volts. The ECO 24 uses three 8 kW elements operating at 240 Volts. The ECO 27 uses three 9 kW elements running at 240 Volts. The ECO 36 uses four 9 kW elements running at 240 Volts.
| Parts Description |
| 1. Electrical Conduit Connection |
| 2. Flow Sensor |
| 3. Ground Connector |
| 4. Terminal Block |
| 5. Triac Cooling Plate |
| 6. Triacs |
| 7. Temperature Control Setting Knob |
| 8. Inlet Temperature Sensor |
| 9. Electronic Board and Protector |
| 10. Fuse and Fuse Holder |
| 11. Copper Heating Elements |
| 12. Thermostats |
| 13. Mounting Bracket |
| 14. Back Casing |
| 15. Copper Heat Exchanger |
| 16. Outlet Temperature Sensor |
| 17. Hot Water Outlet Connection |
| 18. Cold Water Inlet Connection |
