FREQUENTLY ASKED QUESTIONS

WWG thoroughly recommends the good practice of cleansing a heating system as an important part of the boiler installation process. The recommendations within BS7593 should be followed, whilst also paying attention to notes within the boiler’s installation and servicing instructions and those instructions as directed by the flushing agent manufacturer.

It is best practice to cleanse an existing heating system prior to installation of the new boiler. After the boiler has been installed, the heating system should be cleansed of debris and refilled with inhibitor.

Your chosen boiler installer should be fully conversant with all current standards/regulations relating to this part of the installation.

Combi boilers produce hot water at mains pressure, which means they are compatible to either a mains pressure balanced or thermostatically controlled shower.

In contrast, when a regular boiler and cylinder is replaced with a combi boiler, any existing shower should be examined for suitability. This might be a pump assisted power shower, for example, designed for low-pressure systems.

Please seek specialist advice from your boiler installer on the correct shower selection.

When the heating system is cool, the pressure should be between 1 and 1.5 bar on the pressure gauge (the indicator needle would usually be in the green section). If pressure is below 0.5 bar (down in the red section), water has been lost from the system and must be replaced.

Note: The red part of the dial could also indicate the pressure being too high (about 2.75 bar or more). If the pressure gauge indicates high pressure as a result of over filling, you will need to bleed a radiator until the pressure gauge returns between 1 and 1.5 bar.

If pressure rises by more than 1 bar when the heating is up to temperature then the expansion vessel may require repressurising. This will require a service engineer.

The pressure in the system will usually require topping up once or twice a year. If you are having to repressurise your heating system much more frequently, please contact your installer.

Replace. A repair can sometimes be as expensive as a brand new boiler. And you could easily have more problems with a repaired boiler further down the line.

A brand new boiler is usually more efficient and more reliable. Your new boiler will be covered by warranty too – so if it breaks, the manufacturer will repair it with no extra charge. At the end of the day it is 100% your choice!

A flue is a pipe, like a chimney, that carries waste from the boiler outside. You can see your flue exit (the part of the flue that comes out of your house) on the wall or roof of your home.

Flues can either be square or round in shape. If the flue is less than two metres off the ground, or underneath a carport or shelter, it’ll be covered by a guard. This looks like a piece of wire mesh covering the end of the flue.

When you buy a boiler from WWG, we’ll also supply and fit a brand new flue for you, along with all the safety attachments you need.

Make sure you have your boiler serviced at least once a year.

We will contact you at the beginning of the month when your service is due to expire, so you have lots of notice and time to get this booked in.