If your German heater isn’t responding to temperature changes, a thermostat replacement may be the fix. Elsco Heating Elgin offers fast, compatible solutions for Elsco Heating, and possibly Elti, Elka, and Sunflow models.

German Chamotte heater should operate quite  happily for many years
Occasionally though, things do go wrong. Its usually  the thermostat and  sometimes the radiator itself. You may be covered under your suppliers guarantee. Its also possible that you have had many years of excellent service from your heater, you cant remember who you got it from, or the supplier disappeared many years ago.
So what do you do, give up and throw it out?  Or try and get it fixed so you can get many more additional years out of it.

Occasional Issues with German Clay Core Heaters

German clay core heaters are known for their reliability, but over time, certain issues can affect performance. Here’s what to watch for:

🔧 1. Thermostat Failure

• Symptoms: Heater not responding to temperature changes, usually no heat.
• Cause: Worn-out or faulty thermostat unit.
• Fix: Replace with a compatible thermostat — we have them for our Elsco Heaters which are also compatible with Elti, Elka, and some old Sunflow models.. Check pictures to see if they look like yours

🔌 2. Power Supply Disruption

• Symptoms: Heater not turning on, intermittent power.
• Cause: Power surges can sometimes damage your heater
• Loose wiring, tripped fuse, or damaged plug.
• Fix: Visual inspection and electrical test; repair or replace damaged components.

🌡️ 3. Inaccurate Temperature Readings

• Symptoms: Room feels too hot or too cold despite settings.
• Cause: Sensor misalignment or internal calibration drift.
• Fix: Recalibrate or replace the thermostat sensor.

🔄 How to Replace Your Thermostat

Replacing the thermostat on a German clay core heater is a straightforward process if you follow these steps carefully. Always ensure the power is off before starting.

🧰 Tools You’ll Need

• Flathead and Phillips screwdrivers
• Voltage tester
• Replacement thermostat ( Elsco, Elti, Elka, or old Sunflow compatible)
• Wire connectors or terminal block (if needed)

🛠️ Step-by-Step Instructions

1. Turn Off Power
   Switch off the heater at the wall and isolate it from the mains.
   Use a voltage tester to confirm no power is flowing.
2. Remove the Heater Lid
   Unscrew the side panel
   Carefully remove the side panel o expose the thermostat housing.
3. Disconnect the Old Thermostat
   Note the wire positions or take a photo.
   Unscrew or unclip the thermostat from its mount.
   Disconnect wires using a screwdriver
4. Install the New Thermostat
   Match wire positions to the new unit.
   Secure wires using terminal block or connectors.
   Mount the new thermostat in place.
5. Reassemble and Test
   Replace the heater cover and secure all screws.
   Restore power and test the thermostat settings.
   Confirm the heater responds correctly to temperature changes.

Full thermostat replacement instructions are here as a downloadable, printable PDF file.

⚠️ Need Help?

If this looks a little daunting we can supply a complete 600mm high end unit including the thermostat. This is much easier to replace.

Cost of thermostat only £130 including postage and packing

Cost of thermostat in end unit (600mm high only, we don’t stock 380mm end units) £180 including postage and packing

Heater Repair Service

Very infrequently some of the clay cores themselves can break down which doesn’t usually affect the whole heater but cold patches can be found. These are more complex to repair and should only be undertaken by us or a qualified electrician.

Here are detailed instructions. We don’t recommend anybody attempting this without talking to us first Instructions are in printable PDF format .

Contact Elsco Heating for help