Hi, DIYers, Patrick here. Before installing a new heating system, get an assessment done, reduce heat loss, then choose equipment suited to your home. This order helps you avoid paying for a system that is too powerful or poorly adjusted. In 2026, also check the requirements for grants before signing a quote.
What to do right away
- Gather your energy bills and information about your boiler or current heating system.
- Identify cold spots, drafts, and signs of damp.
- Request an energy assessment before choosing new equipment.
- Get quotes for insulation and ventilation at the same time as the heating system.
- Check your eligibility for financial assistance before signing or starting the work.
An energy-efficiency renovation project goes more smoothly with a clear sequence: assess, address heat loss, then size the heating system. For a roadmap, consult this energy-efficiency renovation guide and the steps to take before changing your heating system.
1. Start with a useful energy assessment
An energy assessment helps you understand where heat is escaping and which work will have the greatest impact. Gather your bills, equipment details and, if you have them, your home’s plans. The assessment should take insulation, windows, hot water and ventilation into account—not just the boiler.
Ask for different scenarios and their order of priority. A report that recommends the same equipment without explaining your needs or the constraints of your home is not enough to proceed with a project.
2. Address insulation before installing new heating
Suitable thermal insulation reduces heat loss through the roof, walls or floors. Start with the areas the assessment identifies as priorities. Otherwise, the new appliance will have to make up for heat loss that could have been reduced beforehand.
After insulating, check the ventilation. A more airtight home needs effective air exchange to limit damp and preserve indoor air quality. “A home that retains heat better needs less heating.”
If your house is cold despite having a recent boiler, first look for heat loss and adjustment issues. If your boiler has broken down, have the system and its safety checked before choosing a replacement.
3. Choose a heating system suited to your home
The heating system should be sized after work on the building envelope is complete. A heat pump may be suitable for a well-insulated home, but its efficiency depends in particular on the climate, heat emitters and site layout. A pellet boiler, on the other hand, requires storage space and easy access for fuel deliveries.
As a rough guide, a heat pump often costs around €10,000 to €20,000 and a pellet boiler around €15,000 to €25,000, depending on the model and circumstances. Get several comparable quotes: the output, accessories, removal of the old appliance, commissioning and adjustments should all be clearly listed.
| Option | What to check before choosing | Indicative cost range |
|---|---|---|
| Heat pump | Insulation, heat emitters, outdoor location and noise | €10,000 to €20,000 depending on the model and circumstances |
| Pellet boiler | Storage, delivery access and maintenance | €15,000 to €25,000 depending on the model and circumstances |
| Solar combisystem heating | Sun exposure, available space and backup heating | €10,000 to €15,000 depending on the model and circumstances |
These figures are estimates, not guaranteed prices. The actual cost depends on the floor area, the existing installation and any additional work.
4. Check quotes, grants and insurance
A reliable quote specifies the equipment, stated performance, included work and excluded work. Also check the contractor’s qualifications and insurance certificates, especially professional liability insurance and ten-year liability insurance where applicable.
Available financial assistance and its eligibility criteria may change. Check the current schemes before work begins and confirm the steps to take with the relevant organizations. Do not deduct a grant from a quote until its amount and your eligibility have been confirmed.
A story often makes the point better than a table: one family replaced its boiler before insulating a poorly insulated attic. Comfort improved, but the rooms under the roof remained cold until the insulation work was done.
5. Organize the work in three steps
- Step 1: Get an assessment and set priorities based on heat loss, the condition of your home and your budget.
- Step 2: Request detailed quotes for insulation, ventilation and heating, then check grants and insurance before signing.
- Step 3: Schedule the work in the right order and finish with a written sign-off, noting any outstanding issues.
At sign-off, test the heating and controls, collect the manuals, and keep the invoices and certificates. These documents will be useful for maintenance, warranties or a future sale.
Frequently asked questions before installing new heating
Should you always insulate before changing the heating system?
It is often preferable, because insulation reduces heating needs and makes it possible to size the equipment correctly. An assessment helps set priorities based on the condition of the home and the state of the existing heating system.
Is a heat pump suitable for an older house?
It can be, if the installation is compatible and the home’s heating needs have been assessed. Insulation, radiators, the outdoor location and the local climate all factor into the choice.
When should you apply for financial assistance?
Check the requirements and complete the necessary steps before work begins. Some grants require advance paperwork and the use of a qualified contractor.
Why get several quotes?
Detailed quotes let you compare equipment, services, warranties and additional work, rather than looking only at the total price.
Thanks for reading this far; Patrick