Under section 50 of the Consumer Rights Act 2015, anything a trader says or writes to a consumer about the trader or the service is treated as a term of the contract if the consumer took it into account when deciding to enter the contract or when making any later decision about the service. Sections 51 and 52 add that, where no price or time is fixed, the installer must charge a reasonable price and finish within a reasonable time.

Statements that become contract terms

Section 50(1) says every contract to supply a service is to be treated as including, as a term, anything said or written to the consumer, by or on behalf of the trader, about the trader or the service, if the consumer takes it into account when deciding to enter into the contract or when making any decision about the service after entering into it. For a boiler job that can include what a salesperson says about which model will be fitted, whether pipework is included, how long the work will take, what the guarantee covers, or whether a mess will be cleared. The law applies to statements made by or on behalf of the trader, so an employee or agent counts. The consumer legislation applies across the whole UK, as legislation.gov.uk marks these sections.

Qualifications and agreed changes

Section 50(2) makes such statements subject to two things. The first is anything that qualified them and was said or written to the consumer on the same occasion. The second is any change that the consumer and the trader have expressly agreed, whether before the contract was made or later. Written quotes and messages make it easier to show what was actually said.

Information required before the contract

Section 50(3) separately says that any information the trader provides under regulations 9, 10 or 13 of the Consumer Contracts (Information, Cancellation and Additional Charges) Regulations 2013 is treated as a term of the contract. Those regulations set out the pre-contract information a trader must give in different types of sale. Under section 50(4), a change to that information, made before or after the contract, is not effective unless expressly agreed between the consumer and the trader. The cancellation rules for sales away from business premises are described in the guide to cancelling a boiler installation contract.

When no price is fixed

Section 51 applies where three conditions are met: the consumer has not yet paid a price or other consideration, the contract does not expressly fix a price or say how it is to be fixed, and nothing treated as included under section 50 fixes one either. In that case the contract is treated as including a term that the consumer must pay a reasonable price for the service, and no more. Section 51(3) says that what is a reasonable price is a question of fact, so there is no fixed formula. This is a fallback, and it is most relevant to open-ended arrangements such as work agreed by phone with no estimate. For a normal fixed quote, the quoted price applies and the guide to comparing boiler installation quotes explains what to look for.

When no time is fixed

Section 52 applies where the contract does not expressly fix the time for the service to be performed or say how it is to be fixed, and information treated as included under section 50 does not fix the time either. The contract is then treated as including a term that the trader must perform the service within a reasonable time, and section 52(3) says that what is a reasonable time is a question of fact. For a boiler replacement, whether a delay is reasonable would depend on the circumstances, such as the type of job, parts and access. A date promised in an email or quote can fix the time for these purposes, because under section 50 it can form part of the contract.

What happens if a promise is broken

Sections 50(5) and 52(4) refer to section 54, which sets out the consumer’s rights when a trader breaches a term that these sections require to be treated as included. The remedies, including repeat performance and a price reduction, are described in the guide to poor boiler installation workmanship. A guarantee promised at sale is a separate matter, covered in the guide to boiler guarantees. Time limits are in the guide to limitation periods for a faulty boiler installation.

FAQs

Does a verbal promise count?

Section 50 covers anything said or written, so a spoken promise can be a term if the customer took it into account. Written records make it easier to prove.

Can an installer change a stated price later?

Under section 50(2) the statement is subject to anything that qualified it on the same occasion and to any change expressly agreed between the parties. Changes to information covered by section 50(3) are ineffective unless expressly agreed.

Does section 51 stop an installer charging for extras?

Section 51 applies only where no price is fixed and none has been paid. Where the contract fixes a price or how to fix it, that term applies, subject to the other consumer protections.

The bottom line

Under sections 50 to 52 of the Consumer Rights Act 2015, what an installer says or writes about the boiler job can become part of the contract, information given under the 2013 Regulations cannot be changed without express agreement, and where no price or time is fixed the installer must charge a reasonable price and work within a reasonable time. Those are questions of fact. This is general information, not regulated advice on any specific installation.

Sources

This guide draws on the following primary sources, current as of 24 September 2026:

• legislation.gov.uk, “Consumer Rights Act 2015, section 50: Information about the trader or service to be binding”
• legislation.gov.uk, “Consumer Rights Act 2015, section 51: Reasonable price to be paid for a service”
• legislation.gov.uk, “Consumer Rights Act 2015, section 52: Service to be performed within a reasonable time”

Related guides

Best Boiler Deals is an independent guide. We may earn a fee from some links; this never affects what we write. This article is general information, not regulated advice on any specific installation — always confirm the details with a Gas Safe registered engineer.