Low
1P4 on Atag iR Regular

Your boiler has detected that the water pressure is getting low and needs to be topped up to keep the system running correctly.

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

Pressure 0.5–0.8 bar — filling needed

From this model's manual
Verified against the Atag Is System installation & service manual, page 72.
Plain-English guidance below. Severity, DIY steps, costs and parts are our interpretation to help you act, not text from the manual.

DIY fix possible

Locate the external filling loop, which is usually a silver flexible hose with one or two small taps.Slowly open the tap(s) until you hear water flowing into the system.Watch the pressure gauge on the boiler until it reaches between 1.2 and 1.5 bar, then close the taps tightly.

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