Field tools • Offline ready
HVAC Field Assistant
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Technician toolbox

Field safety: This app is an organizational tool, not a substitute for the exact model's manufacturer instructions, applicable codes, or qualified judgment. Verify gas, combustion, venting, electrical, and pressure procedures against authoritative documentation.

Quick search

Search your locally saved information.

AI troubleshooting assistant

Online feature. Your information is sent to the configured AI service for analysis. Do not include customer names, addresses, access codes, or other private information. AI suggestions are not manufacturer-approved procedures unless supported by a cited source.

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Your diagnostic analysis will appear here when the AI service is connected and you are online.

Rinnai E-Series • E110CP

Model-specific reference. This first offline database is for Rinnai E75CN / E110CN / E75CP / E110CP E-Series boilers using the documented E-Series control. Confirm the full model, fuel, control/display version and manual revision before applying a procedure. Service work must be performed by qualified personnel.

Find a status, block or error

Important display note

To view the technical readout, press and hold STEP for 5 seconds. The first display position is the operating status. Status 0 means no heat demand; it is not, by itself, an error code. Check whether the boiler is actually receiving a central-heating or DHW demand and whether the relevant program is enabled. Use the exact wiring/control documentation for further checks.

The E-Series user manual describes status 0 as “No heat demand” and identifies STEP as the technical-readout toggle. See the source links below.

Manuals and source references

Installation & Servicing Instructions
E75CN / E110CN / E75CP / E110CP • document 8U.51.60.04/11.11 • Blocks & Errors, Chapter 15
Open service manual PDF (online)
Rinnai E-Series User Information Manual
E75CN / E110CN / E75CP / E110CP • document 8U.52.60.03/01.13
Open Rinnai user manual (online)

The lookup entries in this app are stored locally. Opening the PDF links requires an internet connection unless you separately save the PDFs to Technical Library.

Diagnostics

Diagnostic entries are intentionally blank until verified from manufacturer documentation. Add a confirmed reference or note for the exact model and control version.

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Saved equipment

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Technical library

Save document links while online, or use Add file to select PDFs and documents. Files selected here are stored in this browser on this iPhone when supported. Keep a separate backup of important manuals.

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Calculators

Temperature conversion

Result appears here.

Ohm's law

Enter voltage and resistance.

Hydronic water volume estimate

Estimate in US gallons.

Uses a cylindrical pipe estimate. Enter actual internal diameter, not nominal pipe size.

Service records

New service note

Manufacturers