There is no easy way to say this, if you have an older style heating system that relies on heating up hot water and storing it in a hot water tank, then you might as well stand inside lighting up £20 notes for heat instead.
Many of these older style systems where you had a boiler with a cold water feed running to it, which was then heated by the boiler, and the resulting hot water pumped into an insulated copper tank, were made well over twenty years ago, or often even far longer.
After 20 years it is likely to only be running at around 20% of its initial efficiency, which is quite a staggering fact. Whilst the cost of replacing your boiler, and most likely your entire heating system if it is over twenty years old, is not going to be cheap, you will find that having a modern combi boiler installed will mean that the payback period in gas saving is very quick.
Not only that, your older boiler will be very expensive to service for a start, as the parts will be expensive as the boiler is no longer in production. In addition at some point you will eventually find that your heating engineer can no longer get the parts to fix it. And you can guarantee that this is likely to happen at Christmas, or some other vital period such as when it is below freezing outside.
A modern combi boiler is not only highly efficient, but it also produces hot water on demand, whereas with an older style heating system, if the hot water tank ran out you would have to turn the boiler back on and wait for it to refill the hot water tank. This can be very time consuming, and often happens in a busy household.
With a modern combi boiler you simply never run out of hot water. The best thing about them though is their high efficiency compared to older style central heating boilers. Indeed the first thing that you will notice will be your gas bill, indeed you may be checking the gas meter as you cannot believe how low the bill is.
Even by replacing an early combi boiler (Some are now 15 to 20 years old) you will notice a large further saving in gas, with some combi boilers now being “A” rated when it comes to government energy ratings.