Remeha fault code E12
Fault code E12 on a Remeha boiler (including Calenta and Gas) means: Heat exchanger temperature above normal range (limit thermostat STB). 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 E12 on a Remeha boiler indicates: Heat exchanger temperature above normal range (limit thermostat STB).
Fixing fault code E12: step by step
- Read the water pressure on the display or gauge. With the system cold it should be between 1.5 and 2 bar.
- Bleed the radiators with a radiator key, then check the pressure again and top up if needed.
- Check that the radiator valves and underfloor heating circuits are open, so the water can circulate.
- Reset the appliance once. If the code comes straight back, do not keep resetting it.
- If the fault keeps returning, or the boiler gurgles or knocks, the heat exchanger may be fouled. Flushing or replacing it is work for a qualified heating engineer.
Applies to
Remeha Calenta, Gas, Quinta, Tzerra, 115 PRO, 25L CW6, 25S Solo, 28C Combi CW4, 35S, 39 kW Combi, 40C Combi CW5, 40L Combi CW6, Plus M 24C Combi CW3, Plus M 28C Combi CW4, Plus M 39C Combi CW5, 610 connection set with plate heat exchanger, 610 connection set low-loss header, Pro 45 Solo, Pro 65 Solo.
Fault code E12 on other Remeha series
The same code does not mean the same thing on every series. Check the rating plate to see which series you have:
- E12 on Avanta, Calora, 35C CW5 up to 2009, CW4, Calora Tower Gas 35S NL, Combi CW6: MVHR unit check error.
- E12 on Aquanta, up to and including serial no. 0534000660260, from serial no. 0614401329300: MVHR unit failed - Coupling remains open.
- E:12 on Calora Tower, Gas, 210 V2 80/120/160/200 kW, 220 SHL: Maximum boiler temperature exceeded (limit thermostat STB).
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 test point protective cap 5 pcs for e.g. Quinta Ace 65 S62233 € 26.51
- Remeha flue test point protective cap 5 pcs for e.g. Quinta Ace 65 S62232 € 31.26
- Remeha venturi gasket 5 pcs for Quinta and Quinta Ace € 22.43
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 E12 mean?
Heat exchanger temperature above normal range (limit thermostat STB).
How do I fix fault code E12 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 E12?
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 E12 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 →