Nefit fault code 4C
Fault code 4C on a Nefit boiler (including EcomLine) means: Fuse F2 is faulty. Burner thermostat has become too hot. The flow temperature is too high Too many radiators closed, open more radiators. Bypass is fitted too close to the boiler, fit bypass at least 6 metres from the boiler. Reset the appliance once. If the code comes back, a part is usually faulty.
After a safety alert (gas, flue gas, combustion), reset no more than once and call in a certified gas engineer. If you smell gas, call your national gas emergency number or 112 immediately.
Cause
Fault code 4C on a Nefit boiler indicates: Fuse F2 is faulty. Burner thermostat has become too hot. The flow temperature is too high Too many radiators closed, open more radiators. Bypass is fitted too close to the boiler, fit bypass at least 6 metres from the boiler.
Applies to
Nefit EcomLine, HR 11 Economy, HR 22, HR 22 Classic, HR 22 Excellent, HR 30 Excellent, HR 43, HR 43 Classic, HR 43 Excellent.
Fault code 4C on other Nefit series
The same code does not mean the same thing on every series. Check the rating plate to see which series you have:
- 4C on EcomLine, HR 30, HR 30 Classic: Fuse F2 is defective. Burner thermostat has overheated. The flow temperature is too high.
Matching parts
Nefit parts are available from Instalpunt; shipping to EU countries from €12.95 (€16.95 for more distant countries), usually 3–5 working days.
Parts per Nefit-series: ProLine (NxT) · TrendLine (II) · EcomLine · TopLine.
For fault code 4C, the part involved is usually in the category: burner.
This message does not point directly to one faulty part. These are the parts that most often fit this appliance:
- Nefit fuse holder UBA 2 pcs for EcomLine and TopLine € 20.26
- Nefit control sensor for EcomLine € 73.18
- Nefit glow plug € 112.38
Fix it yourself or call an engineer?
Always consult the manual for your appliance and work safely. If in doubt or if the fault comes back, call in a qualified professional. A question about a part? Write to us at info@instalpunt.nl.
Frequently asked questions
What does Nefit boiler fault code 4C mean?
Fuse F2 is faulty. Burner thermostat has become too hot. The flow temperature is too high Too many radiators closed, open more radiators. Bypass is fitted too close to the boiler, fit bypass at least 6 metres from the boiler.
How do I fix fault code 4C on a Nefit boiler?
First check the cause described above. Then restart the appliance using the reset button. If the message comes back, a part usually needs replacing or the fault needs to be repaired by a qualified professional.
Which parts do I need for Nefit fault code 4C?
That depends on the exact cause. In the Nefit parts overview at Instalpunt you will find the current price and stock for each part.
Can I fix fault code 4C myself?
You can reset the appliance and check things like the water pressure or settings yourself. Work on gas-carrying parts must be left to a certified gas engineer.
All Nefit boiler faults and codes at a glance →