Remeha fault code u 452
Fault code u 452 on a Remeha boiler (including Gas) means: Activation of the defrosting function. Defrosting is activated if at least 90 minutes have elapsed since the previous defrosting (or 180 minutes if the temperature is lower than -5 °C), if the burner control unit has been switched on for at least 15 minutes and if the ambient temperature, the hot water at the inlet and the evaporator require it to be activated. 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 u 452 on a Remeha boiler indicates: Activation of the defrosting function. Defrosting is activated if at least 90 minutes have elapsed since the previous defrosting (or 180 minutes if the temperature is lower than -5 °C), if the burner control unit has been switched on for at least 15 minutes and if the ambient temperature, the hot water at the inlet and the evaporator require it to be activated.
Fixing fault code u 452: step by step
- Switch the appliance off at the mains for 30 seconds (unplug it), then switch it back on.
- Is it about communication with the thermostat? Then check the thermostat connection and wiring.
- Reset the appliance once. If the code comes straight back, do not keep resetting it.
- If the code comes back, the PCB or burner control unit is probably faulty. Have the appliance read out first to be sure.
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 452 mean?
Activation of the defrosting function. Defrosting is activated if at least 90 minutes have elapsed since the previous defrosting (or 180 minutes if the temperature is lower than -5 °C), if the burner control unit has been switched on for at least 15 minutes and if the ambient temperature, the hot water at the inlet and the evaporator require it to be activated.
How do I fix fault code u 452 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 452?
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 452 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 →