Valves

Valves for Heating & Hot Water Systems

Valves are essential for the safe operation, control and maintenance of heating and hot water systems. Whether you are replacing a pressure relief valve, thermostatic mixing valve, isolating valve, motorised valve or inlet control component, choosing the correct specification is critical for safety, reliability and long-term system performance.

At Heatraq, we stock genuine and compatible valves for domestic and commercial hot water systems, including Heatrae Sadia and Baxi applications. Use the categories below to narrow your search by valve function, or browse the full range to match your existing part number, connection size and pressure rating.

Browse Valves by Function

Valve Types Explained

Safety & Relief Valves:

Protect heating and hot water systems by safely releasing excess pressure or temperature.

Water Control & Regulation Valves:

Manage flow, pressure and inlet control to ensure consistent system performance.

Mixing & Temperature Control Valves:

Blend hot and cold water to deliver safe and controlled outlet temperatures.

Isolation & Service Valves:

Allow sections of the system to be shut off for maintenance or repair work.

Motorised & Actuated Valves:

Automatically control water flow in heating and hot-water circuits.

System & Auxiliary Valves:

Supporting components such as float valves, strainers and filling valves.

Choosing the Right Valve for Your Heating or Hot Water System

Valves can look similar, but their purpose, pressure rating and installation position can be very different. A pressure relief valve, for example, is designed to protect the system from excess pressure, while a thermostatic mixing valve helps control the delivered water temperature. Isolation valves are used for safe servicing, and control or regulating valves help manage how water moves through the system.

When replacing a valve, it is important to match the original part as closely as possible. Check the manufacturer part number, valve type, connection size, pressure rating and where the valve is fitted within the system. For unvented cylinders and high-pressure hot water systems, safety-critical valves should always be selected carefully and installed by a competent person.

Heatraq supplies valves for a wide range of heating and hot water applications, with product listings organised to help engineers, maintenance teams, and homeowners more easily identify the correct replacement part.

Heating & Hot Water System Valves - FAQs

What types of valves are used in heating and hot water systems?

Common heating and hot water valves include pressure relief valves, temperature and pressure relief valves, thermostatic mixing valves, pressure reducing valves, isolation valves, motorised valves and filling loop valves.

How do I know which replacement valve I need?

Check the part number, valve type, pressure rating, connection size and the appliance or cylinder model. Where possible, match the
replacement valve to the original manufacturer's specification.

What does a pressure relief valve do?

A pressure relief valve helps protect a heating or hot water system by discharging water if pressure rises above the valve’s rated limit.

What is a thermostatic mixing valve used for?

A thermostatic mixing valve blends hot and cold water to help deliver a safer, controlled outlet temperature.

Can I replace a valve myself?

Some basic isolation or service valves may be straightforward for competent
installers, but safety-critical valves on unvented cylinders or pressurised
systems should be replaced by a qualified professional.