Boiler Service Cost by Type: Combi, System, Conventional, Oil & More
Service costs vary significantly by boiler type. Combi boilers are the cheapest and simplest to service; oil boilers require specialist engineers and cost the most. Here is what you will pay for each type in 2026.
Service Cost Comparison at a Glance
| Boiler Type | Service Cost | Duration | Engineer Type | Complexity |
|---|---|---|---|---|
| Combi | £80-120 | 30-45 min | Gas Safe | Low |
| System | £90-130 | 40-55 min | Gas Safe | Medium |
| Conventional/Regular | £100-150 | 50-75 min | Gas Safe | High |
| Oil | £100-180 | 45-75 min | OFTEC | High |
| Electric | £70-120 | 30-45 min | Any qualified | Very low |
| LPG | £90-120 | 35-50 min | Gas Safe (LP Gas) | Medium |
Combi Boiler Service Cost
Combi boilers are the most common type in UK homes and the simplest to service. They have no separate hot water cylinder or cold water tanks - everything is in one wall-mounted unit. The engineer inspects and cleans the heat exchanger, burner, and ignition, checks the flue gas analysis, tests system pressure and controls, and checks the condensate trap. The compact design means faster service and lower cost. If you have a combi and it is under 10 years old, you should have no difficulty finding competitive quotes at £60-90 from a local engineer.
System Boiler Service Cost
System boilers work with a hot water cylinder (usually in an airing cupboard) but have no cold water tanks. They are common in larger homes with multiple bathrooms. The service includes everything a combi service covers plus: checking the hot water cylinder, inspecting the cylinder thermostat, checking the expansion vessel condition, and testing the pump. The extra components mean slightly longer service time and marginally higher cost than a combi.
Conventional (Regular) Boiler Service Cost
Conventional boilers (also called regular or heat-only boilers) are the most complex to service. They have a hot water cylinder, a cold water storage tank (usually in the loft), and a separate feed and expansion tank. More components means more to check. Engineers will also check the condition of the feed tank, inspect all connections for corrosion or leaks, and verify the open-vented system is balanced correctly. The higher price reflects both the time taken and the technical complexity.
Oil Boiler Service Cost
Oil boilers require an OFTEC-registered engineer - you cannot use a standard Gas Safe engineer for oil. OFTEC (Oil Firing Technical Association) registration involves additional training specific to oil-fired appliances. The service includes replacing the oil burner nozzle (essential annual maintenance), cleaning the combustion chamber and heat exchanger, checking the oil filter, inspecting the flue, and performing a combustion efficiency test. The specialist qualification requirement, fewer engineers available, and longer service process all contribute to the higher cost.
Electric Boiler Service Cost
Electric boilers are the simplest and cheapest to service. There is no gas or flue to check, no combustion to analyse. The engineer checks the heating element, inspects the thermostat and controls, tests the pressure relief valve, and checks for limescale buildup in the cylinder. Some manufacturers argue annual servicing is optional for electric boilers, but most still recommend it for warranty compliance and longevity. Note: electric boilers are more expensive to run than gas but cheaper to service and install.
LPG Boiler Service Cost
LPG (liquefied petroleum gas) boilers are similar to natural gas boilers but run on pressurised gas stored in a tank. Engineers must hold a Gas Safe registration with specific LP Gas qualifications. The service is similar to a natural gas boiler service but also includes checking the external regulator, the gas supply pipework from the tank, and ensuring correct operating pressures for LPG. Finding a qualified engineer can be harder in some rural areas, which can drive costs higher.
10-Year Maintenance Cost Comparison
Estimated 10-year cost including annual service and average repair frequency (based on typical reliability data).
| Boiler Type | Annual Service Cost | 10yr Service Total | Avg Repairs (10yr) | 10yr Total |
|---|---|---|---|---|
| Combi | £90 | £900 | ~£300 | ~£1,200 |
| System | £110 | £1,100 | ~£350 | ~£1,450 |
| Conventional | £125 | £1,250 | ~£450 | ~£1,700 |
| Oil | £140 | £1,400 | ~£500 | ~£1,900 |
| Electric | £85 | £850 | ~£150 | ~£1,000 |
| LPG | £105 | £1,050 | ~£350 | ~£1,400 |
Frequently Asked Questions
How much does a combi boiler service cost?
A combi boiler service typically costs £80-120 in the UK, with an average of around £90. Combis are the cheapest to service because they are wall-mounted, compact, and have no separate cylinder or water tanks. The service takes 30-45 minutes. They make up around 70% of UK boiler installations, so most engineers are very familiar with them and quotes are competitive.
Why does an oil boiler service cost more?
Oil boiler services cost £100-180 because they require a specialist OFTEC-registered engineer rather than a standard Gas Safe engineer. The service itself is also more involved - the engineer must replace the oil nozzle, check the oil filter, inspect the combustion chamber, and test for safe oil combustion. There are also fewer OFTEC-registered engineers available, which keeps prices higher. Always verify OFTEC registration before booking an oil boiler service.
Do electric boilers need servicing?
Electric boilers do not legally need to be serviced, and there is no Gas Safe requirement since there is no gas involved. However, manufacturers still recommend annual servicing to check the element, thermostat, pressure relief valve, and controls. An electric boiler service costs £70-120 and takes 30-45 minutes. Skipping it can void some manufacturer warranties, though the safety risk is much lower than with gas boilers.