Radson fault code 8
Fault code 8 on a Radson boiler (including Multicom) means: NTC 2 open circuit or short circuit. Reset the appliance once. If the code comes back, a part is usually faulty, often a temperature sensor. 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 8 on a Radson boiler indicates: NTC 2 open circuit or short circuit.
Fixing fault code 8: step by step
- Reset the appliance once; a one-off measuring error will then clear.
- Where you can reach it without opening the sealed combustion section, check that the sensor plug is seated firmly and the wiring is undamaged.
- If the code comes back, the sensor or its wiring is usually faulty (short or open circuit). Sensors in the sealed combustion section should be replaced by a qualified heating engineer.
Applies to
Radson Multicom, 26HRE, 28.
Matching parts
Radson parts are available from Instalpunt; shipping to EU countries from €12.95 (€16.95 for more distant countries), usually 3–5 working days.
Based on the cause, these original Radson parts fit (always check the type number of your appliance):
- Bosch Radson NTC M6 R € 32.62
- Bosch Radson NTC G1/4" immersion tube € 82.90
- Bosch Radson NTC G1/4" stainless steel L=147mm € 82.90
Further reading on this cause
Other Radson codes with the same cause
- 7 — NTC 1 or 2 open circuit or short circuit
- A6 — Flue gas NTC (4)
- A7 — Return NTC (2) defective
- Ad — Domestic hot water sensor fault.
- CC — Outdoor sensor defective
- E1 — NTC (1) too high
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 Radson boiler fault code 8 mean?
NTC 2 open circuit or short circuit.
How do I fix fault code 8 on a Radson 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 Radson fault code 8?
That depends on the exact cause. In the Radson parts overview at Instalpunt you will find the current price and stock for each part.
Can I fix fault code 8 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 Radson boiler faults and codes at a glance →