Do not treat a higher setting or continued top-up as a diagnosis. Added water can also change the system’s treatment condition, so provide both mechanical and water-treatment records for review.
What information helps diagnosis?
Find the unit and expansion-vessel information, drawings and previous readings. Note alarms, visible leaks, discharge and recent maintenance. Add the time and operating condition to pressure readings rather than supplying isolated numbers.
Explain whether the problem followed draining, a replaced component or changed controls. The contractor may need to investigate the circuit and connected equipment, not just the unit itself.
Leave safety devices alone and do not keep changing settings to suppress warnings. The investigation needs competent work and planned isolation, as described in HSE's maintenance guidance.
Repair and handover
Ask what evidence identifies the cause and what action follows. A repair could concern the unit, expansion provision or a leak elsewhere. The report should distinguish these rather than presenting every pressure problem as the same fault.
Keep the settings, equipment details and checks after repair. Ask whether pressure needs monitoring through heating and cooling cycles; a steady reading at one moment does not cover every operating state.
Use HSE's pressure-system guidance to establish the relevant examination framework with appropriate advice. Do not assume that every sealed water installation falls within the same requirements.
Frequently asked questions
Is pressure loss always caused by the pressurisation unit?
No. Water may be lost elsewhere in the connected system and the unit may be reacting normally. Its behaviour needs assessment in that context.
Can topping up be used as the permanent solution?
Not without explaining the cause. Regular top-up may hide leakage or another fault and affect water treatment. Arrange investigation and repair of the underlying problem.
What should I tell the contractor before the visit?
Give equipment details, alarms, when pressure changes and recent work. Explain which services are affected, access arrangements and who may authorise a shutdown.
Related reading
See circulation-pump faults and mechanical plant maintenance. Explore Mechanical Fault Finding or Water Treatment, or discuss your system with readings, symptoms and the property information.
