NO WATER FLOW error code
NO WATER FLOW – Keston Combi² C30/C35 error code
What does Keston Keston Combi² C30 and C35 gas boilers NO WATER FLOW mean?
Keston documents “No water flow” for the Combi² C30 and C35. This display message identifies a boiler-detected fault or safety condition; confirm the exact wording on the appliance before taking action.
The code identifies the condition detected by the product; it does not always identify the failed component on its own. Confirm the full code and exact model before ordering parts or attempting a reset.
The Keston Keston Combi² C30 and C35 gas boilers NO WATER FLOW error code indicates keston documents “No water flow” for the Combi² C30 and C35. This display message identifies a boiler-detected fault or safety condition; confirm the exact wording on the appliance before taking action. This guide explains what the code means, the symptoms and likely causes, the checks that are safe to make, and when to stop and arrange an authorised repair.
Symptoms you may notice
The boiler displays NO WATER FLOW; heating or hot-water operation may stop, lock out or remain restricted until the underlying condition is corrected.
Common causes
Possible causes are associated with no water flow, including the related sensor, supply, safety, combustion, circulation or controller circuit identified by the official Keston guide.
Before you start troubleshooting
Use the display, rating label or product menu to confirm the exact model. Similar-looking codes can have different meanings across product generations and regions.
- Record the complete code before switching the equipment off.
- Check only user-accessible controls, filters and external connections described in the manual.
- Do not open gas, refrigerant, combustion or electrical compartments.
Troubleshooting steps
With the boiler off and cold, verify pressure, bleed radiators and restore pressure. If the fault remains, contact an installer to diagnose circulation.
Can you fix this error code yourself?
The safest next step depends on the exact model and the cause behind the code. External checks may help, but a returning fault needs professional diagnosis.
A successful reset is not proof that the underlying issue is fixed. If NO WATER FLOW reappears, note when it happens and give that information to the service engineer.
Reset instructions
Record the complete display message first. Restart only where the official message explicitly directs it, and do not repeat resets if the fault returns.
Applicable products and models
Keston Combi² C30 and C35 gas boilersCombi² C30; Combi² C352022 onwardWhen to contact a professional
Contact Keston support or a Gas Safe registered engineer when the message persists, returns after the permitted user check, involves combustion or electrical safety, or requires internal access.
Frequently asked questions
What does Keston Keston Combi² C30 and C35 gas boilers NO WATER FLOW mean?
Keston documents “No water flow” for the Combi² C30 and C35. This display message identifies a boiler-detected fault or safety condition; confirm the exact wording on the appliance before taking action.
Can I fix Keston Keston Combi² C30 and C35 gas boilers NO WATER FLOW myself?
Some external checks may be suitable for the user, but the result depends on the exact model and cause. Use the official manual and arrange service if the code returns.
Should I reset the product after code NO WATER FLOW?
Record the complete display message first. Restart only where the official message explicitly directs it, and do not repeat resets if the fault returns.
When should I arrange a repair?
Contact Keston support or a Gas Safe registered engineer when the message persists, returns after the permitted user check, involves combustion or electrical safety, or requires internal access.