FAQ’s

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 type of boilers work with both vented and unvented how water cylinders. System boilers operate on a sealed system like the combination boiler. As the system is not affected by mains water pressure, they can operate in areas where combi boilers cannot (like lofts). System boilers are usually compact as all the major components like the pump and the diverter valve are built into the boiler. A system boiler is a great choice for a larger home or family with hot water needs that can’t be met by a combi boiler. You will need a tank in the airing cupboard, though.

We can install any type of boilers. We will assess your individual needs and advise on a suitable boiler. There are several very good central heating boiler manufacturers in the market. We usually recommend A-rated Baxi boilers for their efficiency, size and 5-year warranty but we have also found Worcester Bosch and Valliant boilers to be equally good in terms of performance and reliability.

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 (usually found under the kitchen sink) before dividing into two pipes. One of the pipes takes water at mains pressure (high pressure) to the cold tap in the kitchen sink. The other pipe runs up 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 pipes. 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’s why it is usually recommended to have a shower pump to increase the flow rate.

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™. RCB Plumbing is a registered Gas Safe Register™ installer. 

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. Megaflo is a market leading name for unvented cylinders and is manufactured by Heatrae Sadia. 

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 the pressure.

Programmable room thermostats switch the heating system on and off automatically several times a day, or night, to suit regular household 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 set temperature has been reached.
Programmable room thermostats are wireless and can be programmed to suit your lifestyle needs.

This usually means there is air 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 reoccurs we suggest that you have your central heating checked by a heating engineer in case there are any underlying system problems.

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 . 

This usually means that the feed and expansion tank in your loft has run dry which can indicate a problem with the ball valve. This needs addressing quickly and can be resolved by replacing the ball valve.

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

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.

An emersion heater is an electric element which screws into the hot water tank. It is wired to the mains electrical supply via an isolating switch, a thermostat to control the temperature, and sometimes a timer which enables 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.