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Boiler Repair Cost

The average boiler repair cost is £170 to £360 for the most common repairs. A full breakdown of costs along with cost factors are listed on this page.
Low Cost £75 – £145
Average Cost £170 to £360
High Cost £325 – £420

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How Much Does a Boiler Repair Cost?

The average boiler repair cost is £170 to £360 for the most common repairs. One of the most common failures is the gas valve, a boiler valve cost will average out at £230 – £285. A full list of other itemized repairs, including diverter valves, burner, flue, air pressure switch and more can be seen in the table below.

The most expensive boiler repair is the heat exchanger at £385 to £470. If your heat exchanger fails and the boiler isn’t covered by warranty, then it’s probably time to examine the cost for boiler replacement instead of repair.

Whether to repair or replace is discussed in more detail in the FAQs at the end of the post.

Here are common boiler repairs and their cost.

Boiler Repair Cost
Repair Type Cost
Automatic Air Vent £125 – £170
Air Pressure Switch £180 – £210
Burner £265 – £300
Burner Cleaning £75 – £95
De-scaling a Tank £115 – £150
Diverter Valve £325 – £360
Expansion Vessel £280 – £315
Fan £215 – £240
Flue £135 – £160
Gas Valve £230 – £285
Heat Exchanger £385 – £420
Ignition Leads £190 – £225
Pump £195 – £215
PCB – Control Board £240 – £335
Seal Replacement £125 – £185
Thermocouple £135 – £150
Thermostat Replacement £100 – £130

Boiler Repair Cost Factors

The boiler repair price list shows repairs made by a professional. We do not recommend you make a repair yourself unless it is a part that has nothing to do with combustion or the proper venting of the boiler. Repair companies need to have gas safe registration and if you start messing around with the boiler yourself, this can not only invalidate the warrenty but it can also be very dangerous.

The main cost factor, of course, is the price of the part that failed and must be replaced.

However, there are a few cost factors that are more general and will help you estimate where on the cost spectrum your repair will fall.

  • Boiler Size – The more capacity a boiler has, the larger the parts generally are, and the more they will cost.
  • Brand – Some brands (e.g. Grant, Viessman) are known for higher quality, and their parts often cost more than those for cheaper boilers like those from Alpha and Potterton. Ideally, of course, the better the quality, the less often you’ll have a boiler fault.
  • Warranty Length – This goes hand in hand with quality. Better units have 10-year warranties whilst lesser boilers are covered for 5 years. Hence, it is more likely you’ll have to pay full cost for a repair in the first decade if the boiler is a cheaper model.
  • Boiler Accessibility – If the boiler is installed in cramped quarters and is more difficult to access, then cost might be higher. Boiler engineers don’t like working bent over, on their knees or in otherwise tight spots.
  • Repair Time – Engineers determine their quotes by the part price and how long the repair will take. A repair like the heat exchanger requires disassembling much of the boiler, and that takes time and leads to higher cost.
  • Size of the Repair Company – Studies show that larger companies have more overhead and general expenses, so their boiler repair rates are as much as 40% higher. Will you get better service from a large company? It isn’t guaranteed. The best approach is to get quotes from several companies with good reputations and experienced boiler engineers. Choose one you believe will make the repair properly and at a fair price.
  • Where you Live – Hourly rates for boiler engineers in London and nearby are much higher than in other areas. If you live there, you know that everything costs more in your area.
  • Emergency Repairs – Repairs made during off hours such as evenings and weekends may cost 50% most than costs listed in the table above. If you can wait until normal business hours, you might save a lot of money.

Before Calling a Boiler Repair Company

Sometimes the problem is minor and can be resolved without a repair.

Most boiler repair companies ask callers a few questions about the boiler problems before sending out an engineer to diagnose and possibly repair the issue.

  1. Is the water turned on?
  2. Is power turned on? Has the circuit been tripped?
  3. Is the fuel valve open?
  4. If you have an oil tank, is it empty?
  5. If the boiler is giving a fault code, have you checked your boiler manual to know what it is? Does the manual offer a simple solution based on the code?
  6. Is the fault with the radiator? In which case it radiator replacement required.

There’s good reason to do this. If the boiler engineer comes to your home only to find that the problem is a simple one, you might still be charged a minimum rate of 1 hour of time at a cost of £50 to £80 or more depending on where you live and the time of day or week.

Read your Manual

The manufacturer provides a manual that is a wealth of information. Reading it, you will learn how your boiler is supposed to work and what fault codes mean. It lists the codes and what to do to clear them and get the boiler functioning again. If you don’t have your manual, it might be available to view or download from the manufacturer site. The boiler should have a plate on its side showing the model number.

Time Schedule for Repairing a Boiler

How long it takes to repair a boiler really depends on what it wrong with it. Boiler repair time schedules are usually charged in three parts; 1) diagnostics, 2) parts, 3) labour to complete:

  • Fault Diagnosis – Fault diagnosis is usually charged as a fixed standard call out cost and then per hour, usually with a minimum charge of 1 hour. For example, a callout may cost £80 plus £50 per hour thereafter. It usually takes less than 30 minutes to diagnose the fault, but keep in mind the call out and mandatory minimum costs and make sure you ask before you request a call out
  • Parts – Parts vary depending on what’s available, things like switches and pumps are usually kept on the engineers van but other less common things may need to be ordered and can take 24-48 hours
  • Labour – The U.K. national average time to repair a boiler is between 1 and 3 hours.

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Boiler Repair Cost FAQs

These are common questions and their answers.

How long do boilers last?

The average longevity is 15-25 years depending on the brand, how heavily it is used and how well the homeowner maintains it. Having it serviced every few years can improve durability, so it will require fewer repairs and will last longer.

Quality boilers that are given proper care often last 30 years.

What is boiler service, how much does it cost and how often should it be done?

Boiler service is when a qualified engineer checks the boiler to make sure it is working properly and safely. A checklist is gone through, and minor repairs might be suggested that will prevent major repairs later. The boiler will be cleaned and tuned during service.

The rate for boiler service is £65-£115 and should be done every 1-3 years. The older the boiler, the more consistent you should have boiler service.

When should a replacement boiler be considered?

The question of boiler repair vs replacement has many variables.

Age: Once a boiler is 12-15 years old, replacement should be considered. This is especially true if it has already required expensive repairs. A novel approach is to add the age of the boiler in years and the cost of the repair in hundreds of pounds. If the number exceeds 20, then repair is a cost-effective measure.

Example 1: A boiler is eight and requires a £400 repair. 4+8=12. Repair the boiler.

Example 2: A boiler is 17 when the £400 repair is diagnosed. 17+4=21. Replace the boiler.

How long you plan to live in your current home: If replacement is an option due to age or repair cost, then here’s a guiding principle – The longer you intend to stay put, the more sense it makes to upgrade to a new, efficient boiler with a good warranty. In fact a new boiler is a great way to make your home more energy efficient.

However, if you plan to sell your home in a year or two, then maybe making the £400 repair on the old boiler rather than spending £1,500-£3,500 having a new boiler installed would be wise.

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