Ideal Logic Combi 24 30 35 E ES Boiler Expansion Vessel 8L 175551

Product Overview

The Ideal Logic Combi Boiler Expansion Vessel (Part Number: 175551) is an 8-litre pressure management component designed for selected Ideal heating systems.

The expansion vessel forms part of the boiler's sealed central heating circuit, accommodating the expansion of water as its temperature increases during operation.

The vessel contains a flexible diaphragm that separates the heating water from a pressurised gas chamber. This arrangement allows the vessel to absorb changes in water volume, helping to maintain stable system pressure and reduce excessive pressure increases.

Correct expansion vessel operation is important for maintaining appropriate pressure conditions within the heating system.

ℹ️ Product Condition Options:

This part may be available in New or Refurbished condition. Please select your desired option from the dropdown menu above. Refurbished expansion vessels should be professionally inspected and tested to confirm correct pressure retention, diaphragm integrity and overall condition before installation.

Technical Insight & Common Failure Symptoms

The 8-litre expansion vessel is designed to accommodate the thermal expansion of water within the boiler's sealed central heating system.

As the heating water warms and expands, the vessel's internal diaphragm moves against the pressurised gas chamber, allowing the additional water volume to be accommodated without excessive pressure increases.

Over time, expansion vessel performance may be affected by loss of pre-charge pressure, diaphragm deterioration, internal corrosion or leakage.

Possible symptoms that may indicate an expansion vessel or associated heating system problem include:

• Boiler pressure rising excessively when the heating is operating.

• System pressure dropping after the heating cools.

• Frequent need to repressurise the heating system.

• Water discharging from the pressure relief valve.

• Significant pressure fluctuations between hot and cold operation.

• Expansion vessel failing to retain its pre-charge pressure.

• Visible leakage, corrosion or damage affecting the vessel.

These symptoms do not necessarily confirm a faulty expansion vessel, as similar problems may result from system leaks, pressure relief valve faults, incorrect filling pressure or other heating components. Correct professional diagnosis should be carried out before replacement.

Compatibility

This part (MPN: 175551) is associated with selected Ideal Logic Combi, Combi E and Combi ES boiler systems.

Please verify the exact boiler model, GC number, original part number, vessel capacity and connection arrangement against the manufacturer's technical documentation before ordering to ensure correct fitment.

Safety Advice

Boiler expansion vessels and associated pressurised heating components should only be inspected, removed or installed by a suitably qualified and competent heating engineer.

Always isolate the appliance and allow the heating system to cool before carrying out any work. The heating circuit must be safely depressurised in accordance with the manufacturer's servicing instructions. The expansion vessel pre-charge pressure, system filling pressure and all relevant connections must be checked. Appropriate leakage, pressure and operational safety tests must be completed before the boiler is returned to service.