UK Appliance Error Codes

Error code

Ideal Boiler Fault Code HF

The boiler has failed to ignite properly The most likely cause is temporary gas supply interruption. Check first: if the manufacturer permits a user reset, try the standard reset process once.

Last updated: 2 April 2026Boiler faults need a cautious approach

Quick answer

HF: what does it mean and how to fix

high severity

What does it mean?

The boiler has failed to ignite properly

How to fix first

Check whether other gas appliances appear to have lost supply, without dismantling the boiler.

Why is this happening?

Temporary gas supply interruption

When should I call an engineer?

If the fault returns after one reset, stop there and arrange a Gas Safe registered engineer.

What does this error code mean?

Ideal boiler fault code HF usually means the boiler could not ignite or complete its startup sequence correctly.

In practice, HF is commonly linked to Temporary gas supply interruption, Ignition or electrode fault, or Control problem affecting startup.

Start with this safe check: Check whether other gas appliances appear to have lost supply, without dismantling the boiler. If the code returns, the fault worsens, or the appliance does not behave normally, if the fault returns after one reset, stop there and arrange a Gas Safe registered engineer.

Why is this happening?

  1. Temporary gas supply interruption
  2. Ignition or electrode fault
  3. Control problem affecting startup

How to fix this safely

  1. Check whether other gas appliances appear to have lost supply, without dismantling the boiler.
  2. If the manufacturer permits a user reset, try the standard reset process once.
  3. Stop further reset attempts if the fault returns.

Reset steps

  1. Follow the reset instructions shown on the boiler control panel or in the manual.
  2. If the code reappears after one reset, book a qualified engineer.

When to call an engineer

If the fault returns after one reset, stop there and arrange a Gas Safe registered engineer.

Safety warning

Do not remove the boiler casing or try to work on gas, ignition, or combustion components yourself.

Useful hub links

Related ignition fault codes

Relevant guide

Frequently asked questions

Can I keep resetting a Ideal boiler with HF?+

No. If HF returns after one standard user reset, stop there and arrange a qualified engineer if the manual gives no safe next step.

Is HF something I can repair myself?+

Boiler faults should be treated cautiously. Stay within the user checks in the manual, and leave gas, combustion, and internal boiler repairs to a qualified professional.