What is Gas Safe Register?

Gas Safe Register is the official Great Britain and Isle of Man registration scheme for installers and maintenance engineers dealing with natural gas appliances, which replaces the previous system run by CORGI until 1st April 2009. By law, anyone carrying out work on gas installations and appliances in your home, must be on the Gas Safe Register.

What is a condensing boiler?

Condensing boilers are the most energy efficient boilers on the market today. They use less fuel and have lower running costs compared to the older non condensing boilers. The achieve this high level of efficiency by extracting heat contained in the combustion gasses, which would otherwise be lost to the atmosphere. Old, convention boilers have an efficiency rate around 60%, which means that the convert 60% or less of their fuel into heat, while the efficiency of new condensing A rated boilers is above 90%. This literally means that a vast majority of heat produced is used as opposed to passing through the flue to the outside. Energy savings are noticeable and significant cuts on your CO2 footprint and gas bills. There are several types of condensing boilers:

• System boiler: heats your hot water through a hot water cylinder
• Combination (combi) boiler: gives you instant hot water without the need for a cylinder
• Open vented conventional boilers: System is open to atmospheric pressures and requires a small tank located usually in the loft space.

Here are a few examples and guidelines to help you identify the type of condensing boiler most likely suited to your needs:

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What is a combi boiler?

The high efficiency condensing combi or combination boiler combines both a conventional boiler for heating a radiator system and an independent water heater in one compact unit, eliminating the need to a hot water cylinder and cold water storage cistern saving on valuable property space. With a combi boiler hot water is always available instantly and for as long as you need it. Some of the boilers we install have a pre-heat to this function which can save over £80 a year on fuel costs. Additional benefits of having a combi boiler include significant saving on your gas bills and the fact that your hot war comes from the mains pressure so you can enjoy showering without needing a noisy pump.

What is a system boiler?

A system boiler works on the principle of stored hot water. It provides heat for your heating system while being able to heat a hot water cylinder (like a Megaflo). This guarantees simultaneous supply of hot water to all outlets. These types of boilers work with both vented and unvented hot water cylinders. System boilers operate on a sealed system like the combination boiler and incorporate a pump and expansion vessel. As the system is not affected by mains water pressure, they can operate in areas where combi boilers cannot (like lofts). A system boiler is a great choice for a larger family home with hot water needs that can’t be met by a combi boiler. A cylinder tank will still have to be located within the property.

Which boiler manufacturer do you recommend?

We can supply and install any manufactured boilers. We will assess your individual needs and advise you on a suitable boiler. There are several very good central heating boiler manufacturers in the current market which are constantly looking for further means of energy saving. We usually recommend A-rate Vaillant Ecotec plus boilers for their efficiency and versatile adaptability. We have also found Viessman and Worcester Bosch boilers to be good in terms of performance and reliability.

What is a gravity fed (low pressure or open vented) system?

Gravity fed systems are the most common type of water system in the UK. The mains water enters the property and flows through a stopcock before dividing into two pipes. One of the pipes takes water at the mains pressure to the kitchen sink. The other pipe runs into the roof space and fills a large water tank, which feeds the cold taps in the bathroom and the toilet cistern. Water also runs from the tank through a pipe to a hot water cylinder which provides hot water to the bathroom and kitchen sink. The system is called gravity fed because it is only the weight of water falling from the tank which makes it flow through the pies. The water is at a much lower pressure than the mains water (at the kitchen sink) and so a gravity fed system is also called a low pressure system. That is why it is usually recommended to have a shower pump to increase flow rate.

What is an unvented hot water (Megaflow) system?

An unvented hot water system is a cylinder where hot water is stored at mains pressure and therefore hot water flow rates are much better than traditional open vented systems. Megaflow is a market leading name for unvented cylinders and manufactured by Heatrae Sadia however there are a large number of other manufacturers producing the same and in some instances preferable unvented cylinders.

How do I know if I have a low pressure (or unvented) system?

If you have a cold water storage cistern in the loft and a hot water cylinder in an airing cupboard, then you have a typical gravity fed system in your property. Your water pressure is determined by the height of your cold water storage cistern in relation to the appliance outlet. For example, a weak shower could be due to low water pressure, but in an ideal world this could be solved by raising the height of the storage cistern. However, this isn’t always possible and pumps can be used to boost pressure.

What are Thermostatic Raviator Valves (TRVs)?

Thermostatic radiator valves control the temperature of an individual room or area. They are fitted to your radiators and have an internal thermostats to enable pre-set temperature control to individual rooms in your home.

What is a programmable room thermostat and how does it work?

Programmable room thermostats switch the heating system on and off automatically several times a day, or night, to suit regular house hold needs. It works by sensing the air temperature, switching on the heating when the air temperature falls below the thermostat setting, and switching it off once this temperature has been reached. Programmable room thermostats can be wireless and can be used to save further running costs if used remotely when working from home.

Why is my radiator cold at the top and hot at the bottom?

This usually means that air is trapped at the top of your radiator and it is stopping any more hot water filling the radiator. To resolve this problem you can bleed the radiator to release the air by opening the bleed nipple (a small square peg at the top of the radiator, usually protected by a round cast in the radiator body) and allowing the air to hiss out. Hold a cloth close to the bleed nipple and when water starts to come out the air should have gone. If this does not help or the problem re-occurs, we suggested that you have your heating checked by a heating engineer in case there are any underlying system problems.

Why is my radiator hotter at the top than at the bottom?

Assuming the radiator has reached operating temperature, this usually means there is a build-up of sludge and rust at the bottom of your radiator and this displaces any water leaving the bottom of the radiator cold. In this case we advise that you have your heating system power flushed.

Why are my radiator hot downstairs and cold upstairs?

This usually means that the deed and expansion tank in your loft has run dry which can indicate a problem with the ball valve or cold fill being blocked from the small tank in your loft to your central heating system being blocked. This needs addressing quickly and can be resolved by replacing the ball valve or removing said blockage.

Why are my radiators cold downstairs and hot upstairs?

This could indicate a fault central heating pump which should be checked by a heating engineer.

What is power flushing?

Power flushing is a process by which heating systems are cleansed from sludge using chemicals with a power flushing pump. The process makes no mess and causes minimal disturbance to your property as no radiators need to be removed. At the end of the power flushing process, the system contains fresh clean water.

What is an emersion heater?

An immersion heater is an electric element which screws into the hot water cylinder tank. It is wired to the mains electrical supply via an isolation switch, a thermostat to control the temperature with built in overheat stat, and sometimes a timer which enables to you set the times you wish to have the water heated. Using a timer, together with a well insulated tank, it is possible to heat the water during the night, when electricity rates are cheaper, and use it during the day.