Berlingo low heating output

A defective water valve on your 2011 Citroen Berlingo could cause those issues. Low heat suggests coolant flow problems, and the error code probably confirms it. Before replacing the valve, check the cable and plug connections. A loose or corroded connection is surprisingly common.

Thanks. Where exactly are the cable and plug connections, and how should I check them? I'm reasonably handy, but specific guidance would be great.

The water valve on your Berlingo is usually in the engine's cooling system, near the thermostat housing or heater core inlet. Follow the coolant hoses from the heater core towards the engine; the valve should be inline. Check the connector for corrosion, damage, or looseness. Use a multimeter to check for voltage and continuity. A faulty connection is possible, but given the error and poor heating, a blockage or failing valve actuator can't be ruled out. A workshop diagnosis might be best to pinpoint the cause.

Thanks for the detailed explanation. I checked the connections but didn't see anything obvious, so I took it to a workshop. It was the water valve, like I thought! The repair cost 95€. Thanks again!