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BoilerCodes
F1
Ideal fault code

Ideal F1: low water pressure

You can usually fix this

The water pressure in your heating system has dropped too low for the boiler to run. Every Ideal guide we checked gives F1 this meaning, and the usual fix is to top the pressure back up.

Recommended pressure when cold for Ideal boilers: 1.0 to 1.5 bar.

What you can safely do

  1. Let the boiler cool down, then read the pressure gauge.
  2. If it is below 1 bar, top up using the filling loop until it reads between 1 and 1.5 bar. Your user guide shows how.
  3. Close the filling loop fully and check the gauge again.

Call a Gas Safe engineer if

  • The pressure keeps dropping and you have to top up often.
  • You can see water leaking from the boiler or pipework.
Find a Gas Safe engineer near you Opens the official Gas Safe Register search.

Applies to: Logic Combi (ESP1), Exclusive 2. Codes can differ between models, so check your manual.

What F1 means on each Ideal model

From Ideal's own fault tables. Your model name is usually on the front of the boiler or in the user manual.

ModelMeaning
Logic Combi (ESP1)Low water pressure
Exclusive 2Low water pressure

Common questions about Ideal F1

What pressure should an Ideal boiler be?

Ideal's user guides say between 1 and 1.5 bar on the pressure gauge.

Why does my Ideal boiler keep losing pressure?

Ideal notes that air released from a newly filled system can cause a pressure drop. If it keeps happening, water is escaping somewhere and you need an engineer.

Nearby Ideal codes

See all 19 Ideal codes

Sources