Manifold Pressure (inch
The A6 error code on Noritz boilers indicates manifold pressure (inch. Symptoms include to the right until the controller emits a beeping sound. the setting will be not completed, display, display.
Noritz A6 means: manifold pressure (inch. The usual causes are min value, max value or pressures (nr83-dvc) ". You can safely reset the boiler once — if A6 returns, do not keep resetting. A qualified heating engineer should diagnose the root cause.
What Does A6 Mean
The A6 code is shown by the boiler’s control board when it detects manifold pressure (inch. The boiler then stops instead of continuing to run in that condition: the code is the appliance reporting a problem, not proof that the boiler is broken.
| What you see on the boiler |
|---|
| to the right until the controller emits a beeping sound. The setting will be not completed |
| Display |
| Display |
| controller until a tone is heard (2 sec.) and "120"(example) appears on the display. |
| until "11 1" appears on the display. |
Common Causes
Causes documented in 1 technical sources.
| Cause |
|---|
| Min value |
| Max value |
| pressures (NR83-DVC) " |
| *Maximum temperature can be adjusted using the Soft Dip Switches. |
| C |
| <NR83-DVC> |
Safety Warning
A6 involves electrical or pressure-related components. Do not attempt repairs without proper qualifications. Ensure the boiler is electrically isolated before any inspection. If you notice water leaks, unusual sounds, or pressure anomalies, contact a qualified heating engineer immediately.
Parts & Prices
Prices shown are indicative. Actual prices and availability vary by region.
Step-by-Step Diagnosis
Refer to the "Setting list for gas manifold
Check that there is no water flow.
Disconnect electrical power after setting the "POWER" button off on the
if this step is not followed.
Disconnect electrical power after setting the "POWER" button off on the remote
power is reconnected if this step is not followed.
How to Fix It
Press the "FLOW METER ALARM SET" button to change the writer number
Press the "UP" button for 5 sec to change the setting number from "1" to "2"."11 2"
Refer to the "Setting list for gas manifold
Check that there is no water flow.
press and hold both the "UP" and "DOWN" buttons on the Circuit Board as illustrated
press and hold the "FLOW METER ALARM SET" button on the remote
Refer to the Noritz service documentation for the detailed procedure. Only a qualified engineer should carry out these repairs.
Diagnostic Tools
TroubleAtlas Score
What Is the TroubleAtlas Score?
Every boiler model is independently evaluated and scored by TroubleAtlas across 6 dimensions: reliability, efficiency, parts availability, service network, value for money, and user satisfaction. The score helps you compare models and make informed decisions when choosing a new boiler.
See All Boiler Scores →Boiler Breakdown Cover
Boiler Breakdown Cover
Protect against unexpected repair costs. Cover plans include annual service, emergency callouts within 24 hours, and full parts replacement. Compare plans side by side and choose the level of protection that fits your home and budget.
Coverage Plans — Coming SoonConsidering a New Heating System
Considering a New Heating System?
If your boiler or heat pump is over 10 years old, replacing it with a modern condensing boiler or air-source heat pump could save you up to 30% on energy bills and significantly reduce your carbon footprint.
Compare Heating System Prices →
YouTube Channel
Watch the fixes. Follow the channel.
Step-by-step boiler repair guides, equipment reviews, and heating system comparisons from qualified engineers.
New fixes every weekFix in 5
Quick fixes for common boiler faults explained in under 5 minutes
Boiler Comparator
Side-by-side comparisons of popular boiler models
Boiler Reviews
Independent reviews with TroubleAtlas Score ratings
Find a Specialist
Don’t fix it alone. Find a trusted heating engineer near you.
TroubleAtlas connects you with vetted local heating professionals who can inspect, diagnose and repair your boiler safely — no guesswork, no unnecessary call-outs.
Local heating professionals are coming to your area
We’re onboarding Gas Safe registered and licensed HVAC engineers city by city. Check back soon, or search above to see current availability.
TroubleAtlas Pro
Get cited by AI. Get found by customers.
TroubleAtlas Pro puts your business in front of homeowners searching for exactly this fault, and structures your listing so AI assistants can cite you as a trusted source.
- ✓ Appear on error code pages viewed by thousands of homeowners
- ✓ AI assistants cite your listing as a verified local specialist
- ✓ Receive direct leads with customer name and contact details
- ✓ TroubleAtlas Certified badge for your marketing materials
Affected Models
Noritz models that can display fault code A6:
| Model Family | Output Range | Frequency |
|---|---|---|
| All Noritz models | — | Possible |
Frequently Asked Questions
Press the "FLOW METER ALARM SET" button to change the writer number. According to the technical documentation, this is the first check on the list for A6.
A6 is not classified as a high-severity fault, so the boiler can be reset once. If A6 comes back, stop resetting: the underlying cause is still there and needs a qualified heating engineer.