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Quick specs
Part Number
HA-P136
Part Type
Flow sensor assembly
Fits
EcoSmart ECO 18–36, Rheem RTEX/RETEX-18 to 36, Eemax HA, PR and EEM24 18–36 kW, Richmond RMTEX
Application
Electric tankless water heaters
Not sure this fits your unit?
Call us with your model number and we'll confirm the right part before you order.
RHEEM EEMAX & ECOSMART Flow Sensor Assembly HA-P136
Genuine OEM Flow Sensor·For 18-36 kW Heaters
$79.03
-
- Free shipping — most items ship by the next day
Licensed HVAC technician required. Must be installed by a certified professional. Improper installation voids the manufacturer warranty.
Secure payment
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RHEEM EEMAX & ECOSMART Flow Sensor Assembly HA-P136
Licensed HVAC technician required. Must be installed by a certified professional. Improper installation voids the manufacturer warranty.
Need help? (888) 292-0874
- Free shipping — most items ship by the next day
Secure payment
VISA MC AMEX DISC PayPal Affirm CHECK
In stock
In most items, small items ship same day. Complete systems ship next business day.
$79.03
-
Need help? (888) 292-0874
- Free shipping — most items ship by the next day
Secure payment
VISA MC AMEX DISC PayPal Affirm CHECK
Quick specs
Part Number
HA-P136
Part Type
Flow sensor assembly
Fits
EcoSmart ECO 18–36, Rheem RTEX/RETEX-18 to 36, Eemax HA, PR and EEM24 18–36 kW, Richmond RMTEX
Application
Electric tankless water heaters
Not sure this fits your unit?
Call us with your model number and we'll confirm the right part before you order.
RHEEM EEMAX & ECOSMART Flow Sensor Assembly HA-P136
This is the genuine OEM replacement Flow Sensor Assembly (HA-P136 / FSA LS1836) designed specifically for Rheem, Eemax, and EcoSmart 18kW–36kW electric tankless water heaters.
How it works: The flow sensor detects when water begins moving through the unit and sends the signal that triggers the heater to activate. A failed flow sensor means no hot water — even if everything else is working fine.
Quick Diagnosis: If your unit’s LED lights up when you turn the knob but the LED does NOT illuminate when hot water is running, your flow sensor needs replacement. This part is the fix.
Why Buy OEM?
- Genuine manufacturer part — not aftermarket or generic
- Guaranteed to fit and function exactly as the original
- Avoids the reliability issues of unregulated third-party sensors
- Direct drop-in replacement — no modifications needed
Compatible Models
EcoSmart: ECO 18, ECO 24, ECO 27, ECO 36
Eemax HomeAdvantage: HA018240, HA024240, HA027240, HA036240
Eemax ProAdvantage: PR018240, PR024240, PR027240, PR036240
Eemax EEM24 Series: EEM24018, EEM24024, EEM24027, EEM24036
Rheem RTEX Series: RTEX-18, RTEX-24, RTEX-27, RTEX-36
Rheem RETEX Series: RETEX-18, RETEX-24, RETEX-27, RETEX-36
Richmond: RMTEX-18, RMTEX-24, RMTEX-27, RMTEX-36
iHeat / Drakken: AHS18D, AHS27D, AH18, AH27
Key features
- Genuine OEM Flow Sensor — HA-P136 / FSA LS1836 assembly
- For 18-36 kW Heaters — Rheem, Eemax and EcoSmart electric tankless units
- Triggers On-Demand Heat — detects water flow and activates the heater
- Fixes No-Hot-Water Issues — a failed sensor stops heating even when other parts work
Why homeowners choose NAW
Genuine OEM parts
Every part we sell is the real thing — authorized, factory-genuine, and backed by the full manufacturer warranty.
Easy online ordering
Find your part by model number, add to cart, and get it delivered to your door — no middleman, no markup.
30-day hassle-free returns
Ordered the wrong part? Send it back within 30 days.
Help when you need it
Not sure if this is the right part? Call us at (888) 292-0874 and we’ll help you find the correct replacement.
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