Low
Pb on Ideal HP290

Your heat pump has temporarily paused its operation to prevent internal components from freezing during extremely cold weather.

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

Frost protection occurs; outdoor unit will stop operating.

From this model's manual
Verified against the Ideal Hp290 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 code appears when the outside temperature drops low enough that the unit needs to protect its internal pipework and heat exchanger from freezing. It occurs because the system has detected a risk of ice buildup and has paused normal heating to circulate water or activate internal heaters. This is a built-in safety feature designed to prevent permanent damage to the outdoor unit during cold snaps.

This code is strictly seasonal and will only appear during the winter months when outdoor temperatures approach or fall below freezing.

DIY fix possible

Check that the outdoor unit is clear of snow, ice, or leaf debrisEnsure the airflow around the outdoor unit is not obstructedWait for the unit to complete its automatic defrost or warming cycle

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