Getting the Best Boiler Service

Boilers

Getting the Best Boiler Service

By Ellie Simmonds

Find out how you can make sure you get a good boiler service. Plus we reveal the results of our undercover boiler engineers investigation. 

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An annual boiler service is essential for keeping your boiler running smoothly and safely. However, as our undercover investigation has revealed, you can't guarantee a good service - even if you hire a Gas Safe qualified heating engineer. 

Read on to find out what you can do to ensure you get the best boiler service and download our free boiler service checklist. We'll also tell you how much you should expect to pay for a boiler service, so you don't get overcharged, and we reveal the results of our boiler engineer investigation.

Free boiler service checklist

Download our free boiler servicing checklist - this shows you the key things you should expect to have done during a full boiler service.

Download PDF

You should get your boiler serviced every year by a Gas Safe registered engineer. You can arrange a service yourself or through a heating engineer – it should cost about £70. Alternatively, you can get boiler cover through a plan, such as Homecare, that includes a boiler service, but this costs more than £200.

Ask what will be included in the boiler service. Watch the engineer and use our checklist to ensure that they cover the basics. A good boiler service should last at least 30 minutes. If it’s shorter than this, ask why. 

Finally, ask for a written report and check it is accurately filled out. If you have any concerns, contact the Gas Safe Register on 0800 408 5500 or at gassaferegister.co.uk. It's also worth getting a carbon monoxide detector.

Although the checklist should stand you in good stead for most boilers, bear in mind that not all boilers are the same.

Most older conventional systems, for example, have parts such as the heat exchanger, burner and fan that would need to be dismantled and checked. This is not normally necessary for a modern boiler, unless the flue gas analysis suggests there's a problem. 

Paying for boiler servicing

Before paying for repairs, check whether your boiler is still under its initial warranty. Most new boilers typically come with cover for parts and labour in the first one or two years.

Some home insurance also gives you cover for boiler breakdowns, either as standard or as an optional extra, so it's worth checking if you already have this. The cost of adding breakdown cover to insurance cover is usually much less than getting a breakdown contract, but you don't get the same benefits.

You'll probably save money if you pay for services and repairs as you go along, rather than take out a boiler servicing contract - where you pay a monthly fee that also covers repairs. Our analysis shows that for more than nine out of ten Which? members this was more expensive than paying for one-offs. Which? members pay an average of £70 for a one-off boiler service.

The majority of Which? members who have a contract say they pay for peace of mind. If this sounds like you, then we'll help you find the best boiler cover policy for you - see our review of boiler servicing contracts

Which? boiler engineers investigation

For the second year in a row, our hidden cameras have caught boiler engineers carrying out potentially dangerous gas work.

We secretly recorded 10 engineers servicing a boiler. Six were from major brands - AA, British Gas, Corgi, Homeserve, Scottish Power and SSE - and four were independents. The results were shocking:

  • Seven engineers failed to carry out the minimum legal checks.
  • Four didn't fix the gas pressure that we deliberately set too high.
  • One engineer fabricated test results on his paperwork.
  • None fully followed the boiler manufacturer's servicing instructions.

We also exposed engineers making potentially dangerous mistakes. These included not safely isolating the boiler from the electricity supply, not properly testing the safety device (which works to protect householders by shutting the boiler down if a flame isn’t present), letting gas temporarily hiss out into the room and not checking for leaks.

Keep reading to find out the full results of our investigation and to download our free boiler servicing checklist.

Our research

We hid our cameras in a rented house, with an actor posing as the home’s owner. Once we had recorded our secret footage, we called in three highly qualified, independent gas experts to watch the film. They assessed each service against the Gas Safety (Installation and Use) Regulations 1998, the boiler manufacturer’s servicing instructions and any extra customer promises made by the firm. And they found all of the engineers making mistakes.

Our research took place in 2016.

Boiler servicing results firm by firm

Ten engineers came to service our boiler - six from major firms and four from independents. Here's a breakdown of what our undercover cameras revealed.

AA

The engineer met the legal requirements but didn't follow the manufacturer’s servicing instructions by failing to check key components, including the burner and heat exchanger. 

Length of service: 30mins

Cost: £119.88 annual contract

British Gas

The engineer didn't check the boiler’s pressure point for leaks - a legal requirement after adjusting the burner pressure. He failed to follow the manufacturer’s servicing instructions – the second year running that we found a British Gas engineer not doing this. 

He also failed to meet one of British Gas’s eight extra customer promises, as he didn't check key parts of the boiler. He left gas escaping temporarily, and his written report falsely claimed that he had checked the radiators and hot water storage cylinder – he didn’t. 

Length of service: 17mins

Cost: £79.30 for a one-off service

Corgi

The engineer said he couldn’t service the boiler because a replacement part was required, but he did carry out some work. This meant that the legal requirements still applied, but our experts didn’t judge it as a service. 

He didn't find the faulty pressure and so failed to meet the minimum legal requirements. One of our experts said the engineer had ‘left the boiler potentially unsafe’. Last year we found that the Corgi HomePlan engineer had fired the boiler with the case off and didn't follow the manufacturer’s servicing instructions properly. 

Length of service: 45mins

Cost: £293.99 annual contract 

HomeServe

The engineer didn’t check the boiler’s pressure point for leaks, which is a legal requirement after adjusting the burner pressure. He failed to follow the manufacturer’s servicing instructions by not cleaning key parts of the boiler. 

He also didn't meet nine of HomeServe’s 12 extra customer promises, including checking the internal flueway, seals and disturbed gas connections. It was the second year running that we found a HomeServe engineer failing to meet the legal requirements. 

Length of service: 45mins

Cost: £79 for a one-off service 

Scottish Power

The engineer met the legal requirements but didn't follow the manufacturer’s servicing instructions, as he failed to check the fan, heat exchanger or burner. Our experts were concerned to see him temporarily leaving gas hissing out of the boiler. 

Length of service: 38mins 

Cost: £189.60 annual contract 

SSE

The engineer met the legal requirements but didn't follow the manufacturer’s servicing instructions – he didn’t safely isolate the boiler, clean any parts or carry out any preliminary operational checks. He didn’t carry out a proper flue gas analysis and, in the words of our experts, ‘appeared not to be familiar with the model of boiler’ – it was a Potterton Suprima, commonly found in the UK. 

To make matters worse, he also put himself at risk of an electric shock. It was the second year running that we've found an SSE engineer making mistakes – last time, the engineer didn't even take the case off the boiler.

Length of service: One hour 

Cost: £74.40 annual contract 

Independents

Of the four companies we looked at, none met the legal requirements, none followed the manufacturer’s servicing instructions properly, and only one picked up the faulty high gas pressure. One engineer wrote a made-up reading on the paperwork, while another left gas hissing out and fired the boiler with the case off. 

Length of service: Between 25mins and an hour 

Cost: Between £60 and £84 for a one-off service

What the boiler servicing companies say

All the firms said they take safety seriously and wanted to investigate further.

The AA said it was disappointed with the findings and that its company procedures and engineers were regularly inspected to ensure work was carried out to the highest possible safety and quality standards. 

A British Gas spokesman told us its engineers were all Gas Safe registered, and that ‘on the rare occasion an engineer deviates from our high standards we always investigate and intervene.’ 

Corgi said it continually reviewed processes and performance and had introduced further measures to track work completed. 

SSE has re-briefed all its engineers and is examining its training and quality assurance practices. 

Scottish Power said the results of this single visit did not reflect the level of service that its engineers provide, and it would take appropriate action if any procedures had not been fully delivered. 

And Homeserve said: ‘We are taking this very seriously and have re-enforced to our network their professional obligations. As part of this, we will also review and re-enforce our guidelines.

What now for boiler servicing?

To find out why we are, once again, seeing such poor results, we turned to Gas Safe, which is responsible for checking that gas work is done safely, and the engineers themselves. 

One in three of the gas engineers we surveyed (178 engineers, April and May 2016) said they felt that the standards of boiler servicing in general were poor, or very poor. 

Using the Freedom of Information Act, we also discovered that Gas Safe narrowly failed to meet two key targets involving households and gas safety in 2014/2015 (it met 13 of its 17 targets). These were: ‘identifying unsafe gas work through inspection activity’, and ‘identifying non-compliance on non-installation work during inspection activity’. 

We asked Gas Safe what it had to say for itself. It told us that its priority was keeping us safe from dangerous gas work: ‘Inspection results relating to unsafe gas work are dealt with through our robust rules and policies and through enforcement action by the HSE [Health and Safety Executive].’ 

We also shared our findings with the Gas Safe Register and the HSE (which oversees Gas Safe). Both said they would investigate further. But the HSE said that overall Gas Safe ‘performed well and was above target’.

We say

Based on our research, you can't be sure you're getting a good boiler service. We're calling on Gas Safe, the HSE and others involved in gas safety to take action and improve standards. We want:

  • Every customer to receive a full completed, signed and written report,
  • More robust investigations and spot checks into boiler servicing, and
  • Increased scrutiny of policies, practices and training across the industry.

Free boiler service checklist

Download our free boiler servicing checklist - this shows you the key things you should expect to have done during a full boiler service.

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