What to check, in order
- Read the pressure gauge
On the Logic Combi it's on the far left of the boiler. Ideal says it should read between 1 and 1.5 bar.
- Top up with the filling loop
To between 1 and 1.5 bar, following the steps in your user guide.
When to call a Gas Safe engineer
If the pressure keeps dropping, call a Gas Safe registered engineer. Ideal says pressure that keeps falling can mean a leak, and needing to top up often means the system needs checking.
Good to know
- Ideal says a system that has just been filled can lose some pressure as air works its way out.
Quick answers
What does the Ideal F1 fault code mean?
The water pressure in the heating system is too low. Ideal says it needs topping up to between 1 and 1.5 bar.
Can I fix Ideal F1 myself?
Easy (about 15 minutes). Start with: read the pressure gauge; top up with the filling loop. If the pressure keeps dropping, call a Gas Safe registered engineer. Ideal says pressure that keeps falling can mean a leak, and needing to top up often means the system needs checking.
Is Ideal F1 worth repairing?
Usually free. Topping up costs nothing. If you have to do it often, there's a leak or a worn part for an engineer to find.
Checked against
- Ideal Heating: what does my boiler fault code mean
- Ideal Heating: Logic Combi 24, 30 and 35 troubleshooting guide
- Ideal Heating: boiler faults FAQs
Last reviewed October 2026. Manufacturers update their pages, and your manual is the final word. Spotted a mistake? Email contact@appliance-error-codes.com.