Remeha fault code u 401
Fault code u 401 on a Remeha boiler (including Gas) means: Temperature detected by the limit thermostat on the generator body is HIGH. Reset the appliance once. If the code comes back, a part is usually faulty. You can check the water pressure and settings yourself; leave work on gas-carrying parts to a certified gas engineer.
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 u 401 on a Remeha boiler indicates: Temperature detected by the limit thermostat on the generator body is HIGH.
Fixing fault code u 401: step by step
- Let the appliance cool down.
- Check that the radiator valves and underfloor heating circuits are open, so the water can circulate.
- Read the water pressure on the display or gauge. With the system cold it should be between 1.5 and 2 bar.
- Reset the appliance once. If the code comes straight back, do not keep resetting it.
- If the code comes back, too little water is flowing (pump, sludge in the system) or the overheat thermostat is faulty.
Applies to
Remeha Gas, 35 A HP.
Matching parts
Remeha 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 Remeha-series: Tzerra Ace · Tzerra · Avanta Ace · Avanta · Calenta Ace · Calenta · Quinta Ace · Quinta.
This message does not point directly to one faulty part. These are the parts that most often fit this appliance:
- Remeha flue O-ring from SN 333860010 € 11.56
- Remeha 3/4 gasket gas pipe € 12.23
- Remeha gasket ring 1.1/4" (PTFE) € 14.28
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 Remeha boiler fault code u 401 mean?
Temperature detected by the limit thermostat on the generator body is HIGH.
How do I fix fault code u 401 on a Remeha 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 Remeha fault code u 401?
That depends on the exact cause. In the Remeha parts overview at Instalpunt you will find the current price and stock for each part.
Can I fix fault code u 401 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 Remeha boiler faults and codes at a glance →