ATAG Chronic System Pressure Loss

Furnace frequently loses pressure and needs topping up

This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.

If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.

Possible Causes

Leaking radiator or pipe joint, Faulty pressure relief valve (PRV) discharging, Failed internal expansion vessel, Micro-leaks in ATAG hydraulic block

Safety first: Let the system cool before inspecting for leaks; hot water can cause burns.

Inspect all visible pipework, radiators, and valves for signs of water staining or dampness.
Check the PRV discharge pipe outside; if it is dripping or wet, the PRV may be passing and needs replacement.
With the system cold and depressurised, a technician can test and recharge the expansion vessel via its Schrader valve.
A dye test or pressure test may be needed to locate hidden leaks in the system.

Hard 4/5

ATAG expansion vessel

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