Frequently asked questions
All of the answers to common plumbing and heating questions. Should you have a particular question that is not answered here please feel free to get in touch.
Yes. It is recommend systems are thoroughly cleaned using the guidelines under BS7593 before installing a new boiler. Cleaning the system will remove any debris that can inhibit the performance of your new boiler.
Most modern boilers have a back-up battery that will maintain settings in the event of a power outage. Check the manufacturer’s manual to check if your boiler has a memory.
Condensing boilers, also known as combi boilers, are fitted with a heat exchanger to transform latent heat into condensation. Without this heat exchange, energy goes to waste. Condensing boilers, therefore, generate more heat and subsequently use less energy. New models are between 89-95% energy efficient, which is around 30-40% more energy efficient than standard boiler models.
The SEDBUK is an energy efficient rating developed in the UK. The purpose of the metric is to measure Seasonal Efficiency of a Domestic Boiler in the UK. The SEBDUK scale measures the performance of a boiler and ranges from A-G. The most energy-efficient boilers save more than 90% of the energy they generate (ErP) are rated A. The ErP takes into account energy consumption and effectiveness of distribution. The government target for modern boilers is a 95% ErP.
The Energy Saving Trust is a non-profit organisation designed by the UK government to address the effects fuel consumption has on the climate. The organisation works with boiler manufacturers and retailers to promote energy efficiency together with consumers to ensure the general public is educated in the most effective ways of cutting down on energy use. Energy Efficient Advise Centres (EEAC) are position through the UK to provide homeowners with impartial advice about how they can reduce energy consumption in the home. EST assess individual cases and offer advice for free. You can contact the EST to ask about you nearest EEAC here.
Before anybody can install, maintain or repair a gas-fired boiler, they must be on the gas-safe register, the official body for Great Britain and the Isle of Man. If you knowingly allow someone to install a boiler than is not a gas-safe registered engineer you can be prosecuted and fined up to £5000. Whenever you call for the services of a boiler technician, it is recommended that you ensure they are a qualified technician. Ask to see their ID card or conduct our own check on the Gas Safe Register.
The majority of modern boilers are fitted with a backlight to make it easier to adjust the settings in dark spaces.
Optimisers prioritise heat settings so that the ideal temperature is reached at the right moment, typically when temperatures drop and people are at home. This helps to conserve energy, keep your home at a comfortable temperature and reduce your gas bill. You can set the optimiser to suit your individual needs. Settings include when you want the boiler to come on at what temperature, and the optimiser will monitor the temperature to ensure an optimum level of comfort.
When you have a new boiler installed, the installation company are obliged to inform your local council within 30 days. The council will issue one of two certificates, either:
• Exceptional Circumstances
• Completion Certificate
The exceptional circumstances certificates denotes it is impossible to install high-efficiency condensing boilers in that property.
Where a completion certificate is issued you will receive a ‘building regulations compliance’ certificate confirming that the home is gas-safe. You will need these certificates in order to sell your home. If the installation company fails to notify the council, the onus is on the homeowner to inform the local authorities and request the relevant certificate.
Some modern boilers are fitted with outdoor temperature sensors so they can automatically regulate room temperatures. This ensures your home is heated to a comfortable level whilst maintaining the energy efficiency of your boiler.
When installing a boiler that operates from the mains pipe, it is important to check your mains can deliver an adequate amount of water whilst other appliances that use water are in use, e.g running taps, flushing toilet, shower.
If the mains is not able to supply sufficient levels of water, you may not be able to use a tap or flush the toilet if you are using the washing machine, or you may get a cold shock whilst taking a shower when someone fills the kettle.
To avoid a water shortage and maintain heat retention, you can give the boiler priority over other appliances. However, before you can do this, the mains must be capable of producing sufficient water pressure and flow rate. Whilst there may be sufficient mains pressure to supply hot water from multiple sources simultaneously, the flow rate is governed by the size, type and condition of your boiler.
It is important not to confuse pressure and flow. You can measure both on your boiler. Pressure is crucial to making sure your heating system is working properly. It is measured on the pressure gauge which is typically separated into four sections, 1-4 with red and green markings. The needle should be in the green, between 1 and 2 bars are ideal. Water flow is the amount of water that travels through the pipes at any given time. The water board target 9 litres a minute. To determine if your boiler can handle 9l/min or more, refer to the specifications of your boiler. Ideally, you want a water flow of 12-14+ l/min.
Installing a timer requires removing the front panel which subsequently exposes you to high voltages and/or pipes that are attached to the gas supply. When a job involves removing the panel to access the inner workings of a boiler we recommend obtaining the services of a gas-safe engineer. Failing to do so could lead to injury and/or prosecution. Fines can be up to as much as £5000.
When a renewable energy heating system is installed in a property, it’s performance is measured by a couple of factors, energy efficiency (ErP) and Co-efficient of Performance (CoP). CoP measures the heat output of a particular technology in relation to the amount of energy it uses to operate. Its purpose is to measure the performance value of the system.
The difference between efficiency and CoP is that the latter calculates the amount of work the boiler has to do in relation to the amount of heat it is capable of converting.
Efficiency measures how much heat output is produced in relation to how much energy was put in – in other words, what percentage of energy is used. Modern boilers are legally obliged to produce 95% ErP. Most produce 91-92% ErP.
A shower typically requires a water flow of 9 litres. Most combi boilers will handle a shower, but they may not be able to manage a shower and another water outlet simultaneously. Before installing a new combi boiler check the flow rate is sufficient enough to support a shower. If the water flow is too low you may not get enough running water, and if the water pressure is too low, your shower may not have the power to deliver an adequate spray.
For a household with one shower, a water flow rate of 9 or more will suffice. If you have two showers or are likely to be using more than one water outlet at the same time, condensing boilers with a higher water flow rate are better suited.
Kent is a well known hard water area, however, help is at hand. To soften your water it is possible to attach a softening device to your water main. However, it can be complicated. Softened water should not come into direct contact with the central heating system because it can damage the heat exchanger. You would first need to install an external link before installing the softener. It is recommended that you ask a qualified technician to do this for you.
The boiler filling loop provides a temporary connection between the central heating system and the mains water supply. External filling loops are silver braided hoses with two valves that enable you to fill and pressure the heating system with water.
External filling loops are sometimes needed when the boiler pressure drops. The external filling loop promotes the flow of water. However, if you have to keep using a filling loop, you probably have a leak. In this instance, call a gas-safe technician to repair the damage.
It’s also important to note that the filling loop connection can only be used as a temporary measure because there is a risk of contaminating the backflow of water into the mains.
Regularly topping up water flow invites oxygen-rich water into your system and will contaminate the pipes with corrosion and sludge. Water Authority regulations prohibit the long-term use of external filling loops.
The external filling loop should be installed in close proximity to the boiler. If your boiler is in the kitchen the filling loop will go under the sink. If your boiler is upstairs or in the loft, the braided hose will be attached to the nearest pipe. The two ends of the braided hose are attached to the water pipes. It’s important to connect these the right way round otherwise the valve will stop the system from filling up. On the filling loop are two valves. The stop valve is used to control the flow of water. The double check valve prevents the water from flowing back into the mains.
If your boiler is consistently losing pressure, it could be a leak, wear and tear or a fault with the central heating system. Boilers that are 15-25 years old can develop leaks coming from the expansion vessel or the air vent.
The first thing to do is check all visible valve joints in the pipes to look for a leak. Secondly, check for dripping along the relief valve that runs from the boiler to the outside of the house.
Combi boilers heat water directly from the mains which means the calcium bi-carbonate can transmute to calcium carbonate. This creates carbon dioxide which causes the water to look chalky or cloudy. Cloudy water is most commonly found in hard water areas. The look is purely aesthetic and does not affect the quality or the taste of the water. However, if you are put off you may want to use a water filter before drinking.
If you have a condensing boiler, you may occasionally see a white plume being omitted from the flue terminal. The cause of this discharge is simply because the gas emitted from combi boilers is cooler than non-condensing boilers so are visible to the naked eye.
Non-condensing boilers still emit a discharge, but because it is hotter they do not cool down until they are further away from the terminal.