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Diverter Valve

What is a diverter valve?

Diverter valves are part of heating systems that include a combi boiler. They direct water that is heated by the boiler, to either the taps or radiators, depending on what your requirement is at the time.

Unlike, combi boilers, diverter valves are not found within system and regular boilers. The reason being is that these systems store hot water in a cylinder, instead of sending it straight to the taps.

How diverter valves work

With a diverter valve, your boiler will give priority to the hot water over the heating. This means, when you have a shower with the heating on, you will receive hot water over the radiators.

How to spot a diverter valve fault

As diverter valves are moving parts, they can get stuck. Although, this is a problem that is generally only associated with older boilers.

If you either only get lukewarm water from the hot tap or need to turn the heating on to get hot water, or you have plenty of hot water but no heating, then you are likely experiencing an issue with your diverter valve.

Common diverter valve problems

As diverter valves play an important role within combi boilers, an issue with this component could negatively impact the heating and hot water around your home.

In the instance that the water from your hot tap is not warming up, then you can try turning the heating on. If the water heats up as a result, then there is probably a problem with the diverter valve.

When diverter valves get stuck, hot water can still be sent to your taps, but your heating might not necessarily warm up. A stuck diverter valve can also lead to lukewarm water coming from your taps. As this occurs when the diverter valve is stuck slightly open on the heating side, some of the heat going to the taps will be lost.

Diverter valve costs

When you have a new combi boiler installed, it will be fitted with a diverter valve. Although, if you experience a serious issue with this component, it will need to be replaced. For the diverter valve itself, you can expect to pay around £75 to £200. Although this does not cover the cost of installation, which will depend on the engineer doing the job.

Before the installation, the engineer will recommend the type of diverter valve that is best suited to your system. As there are a wide variety of combi boiler models, you will need to ensure that the diverter valve matches the size of your combi boiler.

What to do if you find a fault with your diverter valve

If you find a problem with your boiler’s diverter valve, then you should contact a Gas Safe Registered engineer immediately.

In the case, that your boiler was installed over ten years ago, it might be time to purchase a replacement boiler. Modern boilers, use innovative technology that is reliable and efficient, helping you to reduce your energy bills.

Worcester Bosch Boiler

Homeowners are still able to get a FREE boiler grant or insulation grant via the ECO scheme, which is still available to households that qualify. Warma UK are currently working throughout the UK helping privately owned and rented homes to improve home energy efficiency and save money on rising energy bills.

For more information email –

Or call 03304600065

Apply For Your Government Backed Heating Grant

Following your successful application, we will arrange a free, no obligation survey to ensure the maximum grant is obtained and advise you on the best products to reduce your homes energy usage.

Michael Cornish