Alternating Display 'H 7 / Pxx' — Water pressure too low

What does H 7 / Pxx mean?

The boiler display will show 'H 7' alternating with a 'P' value (e.g., P12), indicating that the water pressure in the heating system is too low. The system's water pressure should typically be between 3 and 12 psi.

• Insufficient water in the heating system
• Leak in the heating system plumbing
• Faulty pressure sensor

Click steps to track your progress.

1. 1

   Note the exact alternating display codes, including the 'P' value, before taking any action.

2. 2

   Contact your installer or heating equipment servicing company to report the low pressure.

3. 3

   A qualified technician will likely need to inspect the system and refill it to the correct operating pressure.

4. 4

   Ensure the heating system is not at risk of freezing, especially if the boiler is not operational in cold weather.