Vaillant
Vaillant Pressure Relief Valve 0020009865
Pressure relief valve for Vaillant Unistor VIH unvented cylinders, part number 0020009865.
At a glance
- Also known as 1379440
£46.55
£38.79 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
The Vaillant 0020009865 is a pressure relief valve used on Unistor VIH unvented hot water cylinders. It opens to discharge excess pressure from the cylinder, protecting the vessel and connected pipework from over-pressurisation. It is a serviceable safety component within the cylinder's pressure control group.
Signs this part needs replacing
- Water continually weeping or dripping from the discharge pipe with no heat-up or draw-off event taking place.
- The valve fails to reseat and seal after being manually opened for testing.
- System pressure will not hold and requires repeated topping up.
- Scale or debris visible at the valve outlet, or the valve body shows corrosion or staining.
- Discharge occurs well below the cylinder's normal operating pressure.
Before you order
- Confirm the cylinder model and serial number against the manufacturer's parts list.
- Check the existing valve's part number or markings match 0020009865.
- Verify the valve is being replaced as part of the correct pressure control arrangement on the cylinder.
- If the cylinder is under warranty or due its annual service, confirm the work falls within the manufacturer's requirements.
Compliance
| Barcode / EAN | 4024074492130 |
|---|---|
| Alternative numbers | 1379440 |
| Make | Model / assembly | Reference | Years | Fitment |
|---|---|---|---|---|
| VAILLANT uniSTOR VIH GB 125 S (2005-2011) | — | — | — | |
| VAILLANT uniSTOR VIH GB 155 S (2005-2011) | — | — | — | |
| VAILLANT uniSTOR VIH GB 180 S (2005-2011) | — | — | — | |
| VAILLANT uniSTOR VIH GB 210 S (2005-2011) | — | — | — | |
| VAILLANT uniSTOR VIH GB 260 S (2005-2011) | — | — | — | |
| VAILLANT uniSTOR VIH GB 310 S (2005-2011) | — | — | — | |
| VAILLANT uniSTOR VIH S 200 S (2005-2011) | — | — | — | |
| VAILLANT uniSTOR VIH S 250 S (2005-2011) | — | — | — | |
| VAILLANT uniSTOR VIH S 300 S (2005-2011) | — | — | — |
Documents & drawings
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