Heating and Hot Water

Hot Water Systems


Water heaters are generally fueled by either natural gas or electricity; however there are some units on the market using LPG and especially for caravan applications there are units that use butane or propane in gas cylinders.

There are single point and multipoint heaters, the difference simply being whether hot water is supplied to one point or to a number of points in the accommodation. Regardless of this the economics of running a unit is governed only by how much hot water you use, the temperature of the water and the fuel used to heat it. The initial cost of the unit is also important, and they vary from £ 100 to £ 1000 depending on their application. To sensibly compare the running costs of various fuel types the graph below show the costs by assuming that the same energy is used to heat the water for the year in a house (All fossil fuel systems are assumed to be 90% efficient). The number used is 5000kWh, which is the average in the UK.


Central Heating


Generally central heating is the most energy and cost efficient way of heating a home, particularly those systems using fuels that are burned in a boiler.  It is also very often one of those areas where you have the least control.  Factors outside of your control may include:-

  • Physical space to install equipment
  • Local regulations  (e.g. which fuels  can you user?)
  • Local infrastructure  (e.g. do you have mains gas?)
  • Do you own the property?
  • Budget (do you have the cash to “upgrade”)

Regardless of these factors, this section aims to show the main general options to heat your home.  For each one of the options presented there is also enormous choice available, for example, there are an unbelievable 4000 types of gas boiler on the market, with variations in brand, performance, and power output.  The correct model for you will depend on you circumstances and a heating engineer will be more able to advise on this.  You should do some research on the which boilers have the best reputation, this could save you a lot of headaches in the long run, do not just rely on the opinion of the installer, they may sell you junk.


Heating Units


The number of methods to provide heating to your accommodations is enormous.  This article compares the potential running costs of various methods of heating. It excludes larger heating systems, like central heating, groundsource heating or airsource heating as these are very different and require large capital expenditure to install. These are considered in a separate article.

To get a meaningful comparison, the same power output and hence the same energy use is used in each case. The calculations are based on each heater having a power output of 3kW, and operating for 5 hours a day for about one third of a year. 3kW was chosen since this is the maximum power output of an electrical heater on a single ring main plug socket and since all the other appliances can out put the same heat power. All appliances are also assumed to be non thermostatically controlled, i.e no maximum room temperature has been set. The rate of heat loss from a room is also not considered here.