County Mayo · Census 2022 and gas meter data
Combi boiler installation in Mayo
Oil is the main fuel in Mayo: 61% of homes. What that means for a new combi, what installers publish, and one installer who covers Mayo.
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In Mayo, 61% of homes heat with oil and 3% with gas (Census 2022), so most combis are oil. 1,112 homes had a gas meter in 2024 (CSO). Published prices: a gas combi swap has a median of €2,600 across 12 installers, and an oil boiler €3,000.
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What's different about a combi in Mayo
Mayo is oil with a little gas. 1,112 homes in the county had a gas meter in 2024, up from 664 in 2015 (CSO, Networked Gas Consumption 2024). In the 2022 Census, Westport was 13% gas, Claremorris 9%, Castlebar 6% and Ballina 3% (CSO, built-up areas file). Across the county 61% of homes heat with oil, and 22% with coal, peat or wood, more than one home in five.
70% of Mayo homes are detached houses. In Castlebar, Ballina, Westport or Claremorris a new combi is almost always oil, and in a big farmhouse with two bathrooms a standard oil boiler with a cylinder may suit better.
Mayo in figures
Every figure for Mayo, against Ireland
| Mayo | Ireland | |
|---|---|---|
| Natural gas | 3% | 33% |
| Oil | 61% | 39% |
| Electricity | 8% | 12% |
| Coal, peat or wood | 22% | 9% |
| Homes with a gas meter, 2024 | 1,112 | 695,199 |
| Median gas use per metered home, 2024 | 6,805 kWh | 7,771 kWh |
| Detached houses | 70% | 41% |
| Built before 1980 | 39% | 42% |
| Built 2001 to 2010 | 26% | 25% |
| Built since 2011 | 7% | 8% |
Sources: CSO Census 2022, Small Area Population Statistics, county file, tables 6.1, 6.2 and 6.5 (households; year built where stated), read 29 October 2026; CSO table F2007A for detached houses; CSO, Networked Gas Consumption 2024, tables 5B and 6B, from Gas Networks Ireland meter data, read 30 October 2026.
Gas or oil, town by town
In Mayo the towns are oil too, not just the countryside. These are the 8 biggest, with the share of households on each fuel in the 2022 Census.
| Town | Homes | Gas | Oil |
|---|---|---|---|
| Castlebar | 5,153 | 6% | 66% |
| Ballina | 4,165 | 3% | 62% |
| Westport | 2,510 | 13% | 47% |
| Claremorris | 1,463 | 9% | 62% |
| Ballinrobe | 1,157 | 8% | 62% |
| Ballyhaunis | 941 | 1% | 66% |
| Swinford | 616 | 1% | 68% |
| Foxford | 635 | 0% | 70% |
Source: CSO Census 2022, Small Area Population Statistics, built-up areas, table 6.5 (households by central heating), and CSO table F1015 (population of towns), read 30 October 2026. Shares are of all households, including those that didn't say.
What changes the job in Mayo
- Gas combi swap. Where there's a gas meter, a like-for-like swap is the usual job, fitted by an RGI. Median published price €2,600, middle half €2,199–€2,800. See every published price.
- Oil combi. 61% of Mayo homes heat with oil. An oil combi or a standard oil boiler is fitted by an OFTEC-registered technician, often outdoors in its own casing. Median published oil boiler price €3,000. See oil combi boilers.
- Big detached houses. 70% of Mayo homes are detached, against 41% nationally. With two or more bathrooms in use at once, a combi shares one flow of hot water; a system boiler with a cylinder may suit better. See combis for large houses.
Running costs in Mayo
The median Mayo home with a gas meter used 6,805 kWh of gas in 2024, against 7,771 kWh for the State (CSO, Networked Gas Consumption 2024, table 5B). At SEAI's unit price of 13.00c a kWh for gas in band D2, including VAT and before standing charges (SEAI, 1 July 2026), that's about €880 a year. That sum is ours.
Met Éireann's 1991 to 2020 averages give Castlebar about 2,028 heating degree days a year, 2% fewer than the Irish average of 2,079 (Met Éireann 30-year averages; degree days are our calculation from the 1 km grid, base 15.5 °C). The same house needs less heat here, so a combi sized for hot water usually has output to spare for the radiators.
Oil is priced the same everywhere: kerosene was 12.60c a kWh on SEAI's 1 July 2026 schedule prices, against 13.00c for gas. See combi running costs for the cost per shower and per year.
What a new combi costs in Mayo
We found no installer based in Mayo that publishes a supplied-and-fitted price on its own website (checked 22 and 23 October 2026). The national figures are the benchmark: 35 installers' published prices, every one linked on the price page.
| Job | Median published price | Middle half | Installers |
|---|---|---|---|
| Combi boiler swap | €2,600 | €2,199–€2,800 | 12 |
| Conversion to a combi | €3,400 | €3,100–€4,000 | 3 |
| System or regular boiler | €2,500 | €2,199–€2,650 | 32 |
| Oil boiler | €3,000 | €2,590–€3,500 | 6 |
Most prices don't say whether VAT is included. Ask for a written price with VAT, the flue, the flush, the filter and the certificate.
Where we cover in Mayo
All of County Mayo, including Castlebar, Ballina, Westport, Claremorris, Ballinrobe and Ballyhaunis. The six biggest towns had 40,260 people between them in 2022 (CSO Census 2022, table F1015). Put your town or Eircode in the form and we pass it to one installer who covers your county.
Nearby: combi boilers in Galway · combi boilers in Donegal · every county.
FAQ
Questions people ask
How much is a combi boiler installed in Mayo?
We found no Mayo installer that publishes a price. Nationally, a like-for-like gas combi swap has a median published price of €2,600 across 12 installers, a conversion €3,400 and an oil boiler €3,000.
Is there gas in Mayo?
A little. 1,112 homes in Mayo had a gas meter in 2024, up from 664 in 2015 (CSO). Westport had the highest gas share of the big towns in the 2022 Census, 13%. 61% of Mayo homes heat with oil.
Do most homes in Mayo need an oil or a gas combi?
Oil, on the 2022 Census: 61% of Mayo homes heat with oil and 3% with gas. A meter box on an outside wall means gas; a tank in the garden means oil.
Is there a grant for a new combi boiler?
No. In SEAI's own words: "We do not give grants for new or replacement fossil fuel boilers, such as gas or oil" (SEAI, read 29 October 2026). You may get the €700 heating controls grant if your home was built and occupied before 2011 (SEAI), and with a combi SEAI requires an extra heating zone as part of that work. The €2,000 boiler scrappage grant only applies when a heat pump replaces the boiler.
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Where these numbers come from (9 public sources, checked 29 October 2026)
- CSO: cso.ie/en/releasesandpublications/ep/p-ngc/networked…
- CSO, built-up areas file: cso.ie/en/media/csoie/census/census2022/SAPS_2022_BU…
- CSO Census 2022, Small Area Population Statistics: cso.ie/en/census/census2022/census2022smallareapopul…
- CSO table F2007A: data.cso.ie/table/F2007A
- CSO table F1015: data.cso.ie/table/F1015
- SEAI, 1 July 2026: seai.ie/publications/Domestic-Fuel-Cost-Comparison.pdf
- Met Éireann 30-year averages: met.ie/climate/30-year-averages
- SEAI: seai.ie/grants/home-energy-grants/individual-grants/s…
- SEAI: seai.ie/grants/home-energy-grants/individual-grants/h…