Boiler losing pressure with no visible leak

Pressure can fall for more than one reason. A visible fitting, a boiler component or concealed heating pipework may be involved. Repeated topping up does not establish which of these is responsible. Existing findings from a qualified boiler engineer can help avoid investigating the wrong part of the system.

If you already know whether the pressure falls while the heating runs or while it is off, tell the investigator. Mention recent radiator work, underfloor heating and any leak-sealing products previously added. You do not need to carry out tests or keep operating a faulty system to make an enquiry.

Where evidence points towards concealed heating pipework, suitable isolation and testing help focus the investigation. Thermal patterns and tracer testing may contribute. The method is chosen for the system and circumstances, and repair access is discussed when the findings justify it.

Do not remove a boiler cover or attempt gas appliance work. A concealed pipe investigation and boiler servicing address different problems. Explain any earlier diagnosis when enquiring so the appropriate scope can be confirmed.

Tell us about any previous boiler assessment and whether there are separate zones or underfloor heating. No home testing is required; the engineer will advise on the conditions useful for the visit.

Central heating leak detection

Find concealed heating-pipe leaks when pressure keeps falling.

Check your area or tell us what you have noticed.