BoilerFaultCodesWhat the manual says
Manufacturer manualWater pressure sensor check is running, demand (DHW or heating) is blocked
What causes this fault?
This code appears when the boiler's internal computer is waiting for a confirmed signal from the water pressure sensor before it allows the burner to light. It is often caused by a failing pressure sensor that is slow to report data or a loss of air in the expansion vessel causing pressure fluctuations. Essentially, the boiler is playing it safe by double-checking there is enough water inside to prevent overheating.
This fault is more frequent in autumn when the heating is turned on for the first time after summer, as stagnant sensors can stick or expansion vessels may have lost charge over the warmer months.
DIY fix possible
Wait 1 to 5 minutes for the automated check to completeCheck the digital display or pressure gauge to ensure water pressure is between 1.0 and 1.5 barIf the code persists, try resetting the boiler
Avoid the next call-out bill
A cover plan would handle faults like S.97: no call-out fees, no surprise bills.
Affiliate links. We may earn a commission at no extra cost to you.