Case study
A.O. Smith water heater: local CTA-2045 control and protocol findings
The A.O. Smith water-heater project implements local monitoring and demand-response control of an HPS10-50H45DV over its CTA-2045 RS-485 port, publishing readings to MQTT. Its documentation records frame structure, checksums, control responses and observed behavior of this specific tank.
- Targets
- Protocol
- Category
- Independent reconstruction cases
- Relationship
- Independent reconstruction project
- Sources reviewed
Requirements & limits
- Prerequisites: Requires an A.O. Smith HPS10-50H45DV, a Raspberry Pi Zero 2 W and an isolated RS-485 adapter as documented.
- Prerequisites: The documented setup uses Raspberry Pi OS Lite, Python 3.13 and a 19200 8N1 serial port.
- Limits: Setpoint writes, water-temperature reads and operating-mode changes are unavailable through this tank's CTA-2045 port.
- License: MIT license.
About this entry
The description was reviewed against primary sources.
Primary sources
- README.md GitHub · ericboehs/aosmith-water-heater · Revision 4145daa
- ARCHITECTURE.md GitHub · ericboehs/aosmith-water-heater · Revision 4145daa
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