Baxi Boiler Duo Tec Combi 3-Bar Safety Valve

This Baxi Duo Tec Combi 3-Bar Safety Valve releases excess pressure from the boiler to protect the system. If it’s leaking or the discharge pipe keeps dripping, you may see pressure dropping, frequent top-ups, or intermittent lockouts. Replacing it with the correct Baxi valve restores stable pressure control, improves safety, and reduces shutdown risk caused by over pressure.

Compatibility:

• Duo Tec Combi ErP (Serial ending DC): 24, 28, 33, 40
• Combi ErP (Serial ending EC): 24, 28, 33, 40
• Duo Tec 24 Combi ErP (DC)
• Duo Tec 28 Combi ErP (DC)
• Duo Tec 33 Combi ErP (DC)
• Duo Tec 40 Combi ErP (DC)
• 24 Combi ErP (EC)
• 28 Combi ErP (EC)
• 33 Combi ErP (EC)
• 40 Combi ErP (EC)

Important fitting advice

We recommend that all parts are fitted by a fully qualified Gas Safe registered engineer. If you need help confirming the right part, contact us our team has 10+ years of boiler spares knowledge and friendly chat support to help you quickly.

Delivery

At Boiler Spares Hub, we dispatch orders within 1 working day (Monday-Friday). Orders placed outside working days will be dispatched on the next working day. For delivery options available for this product, please add it to your basket or check our delivery options page.

Returns

We accept 30-day returns. Returns must be in an unopened, sealed box. If we find the item has been used or installation was attempted, we may refuse the return.

Frequently Asked Questions (FAQs)

1. What is the function of the safety valve?
The primary purpose of a safety valve is the protection of life, property and environment. A safety valve is designed to open and relieve excess pressure from vessels or equipment and to reclose and prevent the further release of fluid after normal conditions have been restored.

2. What is the pressure of a boiler safety valve?
Safety valves protect the boiler from overpressure by releasing pressure when it rises too high. Set both safety valves so they open at no more than 3% above the normal working pressure shown on the name plate. For example, if the boiler works at 7 bar, 3% equals 0.21 bar, so the valves must not exceed 7.21 bar.

3. What is a Baxi 3 way valve assembly with bypass?
The Baxi 3-way valve assembly with bypass is a part that is only found in combi boilers and allows hot water to be sent to the central heating system or the hot water system. This feature distinguishes a regular boiler from a combination boiler.

4. How many types of safety valves are there?
There are two main types of safety valves. Spring loaded safety valves and pilot operated safety valves. Overpressure is the pressure increase above the set pressure necessary for the safety valve to achieve full lift and capacity.