When do I have to replace my central heating boiler?

It is a good idea to replace your gas boiler if it is more than 15 to 20 years old even if it is still running.

Reasons to change your gas boiler

New models can save up to 30% gas and are therefore self-financing, so to speak. In some cases a payback period for this investment is 5 to 6 years. And if you plan to move in the meantime, your new boiler will add up to the value of your property anyway.

On top of that, between 2020 and 2023, Brussels moves onto rich gas. Pre-1978 boilers are not compatible with this gas and therefore have to be replaced in any case. So it’s just as well to get ahead! Make the most of the Brussels Environment energy grants and save money..

7 things to consider to make the right choices

1. Before the boiler - insulation

There is no point in investing in more efficient heating if the heat is not kept inside your home. If your roof is not yet insulated, start with that!

Good insulation will make your old boiler more efficient and you can use the savings made to set aside money for your new boiler.

2. Take your time

Buying a new gas boiler is a serious investment. So take the time to set your budget, meet professionals, compare quotes, etc.

A good plan: visit Batibouw and other building trade fairs held at the beginning of the year to make the most of special offers.

You can schedule your work during the summer: the ideal moment for work on your installation. The professionals are normally less busy and you can do without heating as the work takes place.

3. Choose the system most suitable for your needs

Condensing boiler or heat pump? Your heat pump options can be limited if you live in town, as there is not normally enough space for certain models. However, a reversible heat pump has the advantage of cooling your home in summer and is even more economical if it is supplied by photovoltaic panels.

Also, if your current boiler also produces the domestic hot water, perhaps the time has come to separate the two functions. A thermodynamic boiler will provide you with the same comfort and consume less. And your boiler will no longer have to tick over in summer just to give you a hot shower...

4. Take account of the costs of adapting your installation

Nowadays, condensing boilers are fitted as standard. If your old boiler was not a condensing boiler, you are probably going to have to adapt your installation at 3 levels:

1.  Your chimney must withstand moisture and it may be necessary to line it.
2. A PVC exhaust channel connected to the drain must be installed to remove the condensates.
3. Your radiators must be large enough or your insulation effective enough to operate with a condensing boiler that produces less hot water than the old models.

5. Make the most of financial aids and special offers

Replacing a gas boiler is an expensive business*. To reduce the impact on your pocket, investigate the energy grants available from your local council and from Brussels Environment. Take advantage also of special offers during building salons, for example.

Do you perhaps also have the possibility of taking out a social loan or energy loan at a very low rate? Remember that replacing your gas boiler will be a way of reducing your energy bill. Wouldn’t it be worth spending the same sum for several years to pay off a small loan rather than “burning” it indefinitely in a greedy boiler?

_{(*) In many of the old heating systems, asbestos wrap is used for the ducts. If this is the case in your house, keep in mind the additional asbestos removal costs.}

The investment is still too much for you?

• You can also ask your heating engineer whether the preparatory work can be spread out. For example, have the chimney lined or certain radiators boosted or a wall insulated in the first year. Then order other preparatory work later on, but in the correct order. Above all, avoid having to “do and undo”.
• Try to find out how much your old boiler is worth when selling it for scap. Especially if you own an old (and heavy) boiler, you could soon be receiving some nice hard cash due to its metal value. 

6. Adopt a modern control system

Don’t compromise on a programmable thermostat and outdoor probe when changing your boiler. This is another source of comfort and additional savings.

Also, take advantage of a visit from your heating engineer to have him check the thermostatic valves (and have them installed urgently if there are none!), as these valves have a limited service life. They can fail after ten or so years or simply seize, but can be adjusted easily.

7. Make an in-depth review of how you heat your home

Do not stop with the boiler replacement. Take a look at your heating habits as a whole.

• What if you lowered the temperature in the bedrooms and used a warmer duvet?
• What if you lowered the ambient temperature during the day by one degree?
• What would you say to additional heating? A pellet stove is easy to install anywhere and can make the living room more comfortable, with the visual attraction of flames, whilst reducing your overall gas consumption.