CEE recommends replacing a boiler when you are 25 years of age or older. A boiler can operate beyond this age, but it will operate less efficiently and is more likely to need more frequent repairs as it ages. This means that you'll pay more to heat your home as your boiler ages. When considering repairing or replacing a boiler, first assess the condition of the metal from which the boiler is made, by any available means.
If the boiler is almost rusty, it should probably be replaced soon. If the condition of the metal does not indicate short-term problems, a good step is to estimate the cost of a new boiler versus the cost of making enough improvements to the existing boiler to work as well as a new one. The decision can then be made to conserve or replace the boiler. Unfortunately, few boilers receive treatment for new doors or cleaning covers, and many boilers are replaced when flue gas leaks worsen.
Or, at a minimum, you would receive quotes for both replacement and repair and make a decision based on the facts. The ideal is to replace it before it completely abandons the ghost, rather than waiting for it to die on a cold winter night. However, keep in mind that even a functioning boiler that is several decades old may need to be replaced. By contrast, new condensing boilers are usually more than 90% efficient, so you can save significantly on your bills if you buy a modern replacement boiler.
My advice is that the 10 years to replace the boiler isn't too bad, because the better it is (Vaillant and Worcester), maybe you can delay it a bit. It's not uncommon for homeowners or facility managers to wait until a boiler breaks down completely before replacing the unit. Either way, here you can get quotes for boiler repairs and replacements from several heating engineers. When you ask a customer who has a 30-year-old boiler that they “haven't had any problems” if any of the other components of the central heating system have had to be replaced, they've almost always done so.
In the case of a steel boiler, the boiler and its controls and the burner are generally removed and replaced when the boiler is replaced, since it is economical and some codes prohibit the installation of used parts. This combination of old and old technology means that an older boiler is likely to have significantly higher annual operating costs, compared to a modern replacement, up to 300 pounds sterling per year in a typical townhouse. We replaced many of the ideal combination boilers around the age of 8 and up, the Bosch combination boilers in Worcester around the age of 12. While the tubes rust and are replaced over the years, the rest of the boiler also rusts, but the damage to other parts of the boiler is not as noticeable because the thicker metal the rest of the boiler is made of takes longer to rust. If you're replacing an electric oven or moving from a heat pump to an electric oven, you're lucky to be at the cheaper end of the furnace replacement spectrum.
Another reason to consider replacing it is when your old boiler is out of warranty and faces constant repair costs that reach hundreds of pounds.