Sime
Sime Rectangle Expansion Vessel 8 Litre 1/2 Inch Male 5183711
Rectangular 8 litre expansion vessel with a 1/2 inch male connection, made by Sime for its Format and Dewy Zip boiler ranges.
At a glance
- Part type: expansion vessel
£89.87
£74.89 ex. VAT · VAT at 20%
Same-day dispatch
Ordered by 4pm Mon–Fri, 10:30am Sat.
30-day returns
Unused, in original packaging.
What it is
A rectangular expansion vessel with an 8 litre capacity and a 1/2 inch male connection, manufactured by Sime. It is fitted within the boiler to absorb the volume increase of the heating water as it heats and expands, holding system pressure within safe limits. It is used across a number of Sime Format and Dewy Zip boiler models.
Signs this part needs replacing
- System pressure rises sharply when the boiler heats up and falls again once it cools.
- The boiler loses pressure repeatedly and needs frequent topping up.
- Water or moisture is present at the vessel's air valve when the valve core is depressed.
- The vessel feels heavy or sounds full of water when tapped, indicating a failed internal diaphragm.
- The pressure relief valve discharges during normal heating cycles.
Before you order
- Confirm your boiler model and part number against the manufacturer's parts list.
- Check the connection size and orientation match the existing vessel on your appliance.
- Check the available space and mounting arrangement will accept a rectangular vessel of this capacity.
- Confirm the system has been depressurised and drained before removal of the old vessel.
No specification data held for this part.
| Make | Model / assembly | Reference | Years | Fitment |
|---|---|---|---|---|
| SIME DEWY ZIP BF 25 SOLAR MET - 8101215 | — | — | — | |
| SIME DEWY ZIP BF 30 SOLAR MET - 8101216 | — | — | — | |
| SIME FORMAT 30 HE - 8101206 | 47-719-22 | 47-719-22 | — | — |
| SIME FORMAT DEWY ZIP 25 BF GPL - 8101201 | — | — | — | |
| SIME FORMAT DEWY ZIP 25 BF MET - 8101200 | — | — | — | |
| SIME FORMAT DEWY ZIP 30 BF GPL - 8101203 | — | — | — | |
| SIME FORMAT DEWY ZIP 30 BF MET - 8101202 | — | — | — | |
| SIME FORMAT SYSTEM 25 HE - 8101250 | 41-719-17 | 41-719-17 | — | — |
| SIME OPEN DEWY ZIP 25 BF MET - 8104900 | — | — | — | |
| SIME OPEN DEWY ZIP 25/40 MET - 8104901 | — | — | — |
Showing 10 of 12 compatible appliances.
Documents & drawings
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