Itho Daalderop fault code 28
Fault code 28 on an Itho Daalderop boiler (including AquaMax DV and Base Cube) means: Domestic hot water sensor faulty. 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 28 on an Itho Daalderop boiler indicates: Domestic hot water sensor faulty.
Fixing fault code 28: 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
Itho Daalderop AquaMax DV, Base Cube, 24/35 (16L) cw 5, 30/35 (16L) cw 5, HR24 Tapklasse CW 4 black, HR30 CW5 black, HR36 Tapklasse CW 5+ black, HR42 25L black.
Matching parts
Itho Daalderop 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 Itho Daalderop parts fit (always check the type number of your appliance):
- Itho Daalderop service set pressure sensor € 133.19
- Itho Daalderop service set temperature sensor (set of 5 pcs) € 206.58
- Itho Daalderop flow meter flow sensor € 217.45
Further reading on this cause
Other Itho Daalderop codes with the same cause
- 0 1 — Open circuit flow sensor (S1)
- 0 2 — Open circuit return sensor (S2)
- 0 5 — Open circuit hot water sensor (S5)
- 0 F1 — Short circuit flow sensor (S1)
- 0 F2 — Short circuit return sensor (S2)
- 0 F5 — short circuit hot water sensor (S5)
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 Itho Daalderop boiler fault code 28 mean?
Domestic hot water sensor faulty.
How do I fix fault code 28 on an Itho Daalderop 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 Itho Daalderop fault code 28?
That depends on the exact cause. In the Itho Daalderop parts overview at Instalpunt you will find the current price and stock for each part.
Can I fix fault code 28 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 Itho Daalderop boiler faults and codes at a glance →