Low
LED4 on Ideal Mexico Super 40ff - 80ff

Your boiler is receiving electrical power and is currently functioning normally, as this light is a status indicator rather than a fault.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Monitor it

This is a minor fault. Keep an eye on it and mention it at your next annual boiler service. Reset the boiler and see if it clears.

What the manual says

Manufacturer manual

Mains electricity on

From this model's manual
Verified against the Ideal Mexico Super 40ff 80ff installation & service manual.
Plain-English guidance below. Severity, DIY steps, costs and parts are our interpretation to help you act, not text from the manual.

What causes this fault?

This LED is not actually a fault, but an indicator that your boiler is connected to the mains electricity and receiving power. It signifies that the internal control board is live and ready to operate the heating or hot water when called upon. If this is the only light visible, it confirms the unit is in a standard standby or operational state.

DIY fix possible

This fault may be fixable without an engineer. Check your manual first.

Find a Gas Safe engineer
Search the official register →
Boiler cover options

Avoid the next call-out bill

A cover plan would handle faults like LED4: no call-out fees, no surprise bills.

Approved partner
Domestic Appliance Guard
Unlimited call-outs, 24/7 helpline, no price-hike promise
Get a quote →

Affiliate links. We may earn a commission at no extra cost to you.

Related fault codes

LED 2View →LED 3View →

Related guides you might find useful

Boiler won't turn on — 9-step checklist

Work through these before the call-out.

Read →

Is boiler cover worth it?

Break-even maths on monthly cover.

Read →

When to replace your boiler

7 signs repair isn't worth it anymore.

Read →