If you have a complaint about your heat supplier, you must contact them to explain your complaint before taking any other action. 

Heat Trust New Icons 02

  • Keep a record of all events and conversations about your complaint. Include times and dates, what happened, who you spoke to and what was said. Keep copies of any other relevant information like meter readings, bills and bank statements.
  • Know what you would like your supplier to do to resolve your complaint. This could be a change in service, an apology and/or financial compensation.

If you've complained to your heat supplier and they've not resolved the issue to your satisfaction after eight weeks, or you've received an earlier 'deadlock' letter from your heat supplier, then:

  • If your heat network is registered with Heat Trust: Read the rest of this page below to find out how to refer your complaint to the independent Energy Ombudsman for free. The Energy Ombudsman has a record of all the heat networks registered with us and will take our Scheme standards into account. Heat Trust itself can't investigate complaints or make enquiries on behalf of individual consumers. We require heat suppliers for our registered heat networks to have a robust complaints process and we have an arrangement with the Energy Ombudsman to process unresolved Scheme complaints. We receive regular Scheme complaints-monitoring data from our registered heat networks and the ombudsman. 
  • If your heat network isn't registered with Heat Trust: Your heat network isn't bound by Heat Trust's Scheme standards. But you can still take a complaint to the Energy Ombudsman about an issue with your heat network that occured on or after 1 April 2025, as the government has made this service available to all heat network consumers from that date. This service is separate to Heat Trust's Scheme and isn't subject to any Heat Trust oversight. The Energy Ombudsman may have other criteria for accepting your complaint, so you should refer to its information at www.energyombudsman.org before proceeding. Because non-Heat Trust registered heat networks aren't subject to our standards, they may not follow all the complaint process stages set out on this page.

If you're not sure if your heat network is registered with Heat Trust, you can check this here.

How to make a complaint:

You must give your heat supplier the opportunity to resolve the problem before taking any other action. Let them know of any problems as soon as possible, as the sooner you tell them the sooner they can put things right. It can also stop issues from escalating further.

Don't be scared of complaining. Complaining can resolve issues and stop problems happening again.

Contact details for your heat supplier will be included in your heat bill, account statement or customer information pack. Heat Trust requires heat suppliers for our registered heat networks to have a clear complaints-handling process, and we expect them to resolve complaints within eight weeks.

We don't recommend that you cancel direct debits, or stop paying your heat charges, as this could make the situation worse. If your complaint is about a bill, we suggest telling your heat supplier that you're paying under protest and ask if they can put the disputed part of the bill on hold. If you can't afford your bills, you should always ask your heat supplier for help in the first instance.

Within eight weeks of you registering your complaint, your heat supplier should send you a letter setting out its final position.

If you're unhappy with your heat supplier’s final offer to resolve your complaint, or it's been over eight weeks and you haven't had a letter from your heat supplier, then follow Steps 3-5.

You can do this:

  • Online at www.energyombudsman.org/raise-dispute 
  • By phone on 0330 440 1624
  • By email to This email address is being protected from spambots. You need JavaScript enabled to view it.
  • By post to Energy Ombudsman, PO Box 966, Warrington, WA4 9DF.

You'll need the name of your heat supplier (if you're unsure who this is, then check your bill, account statement or customer information pack). The Energy Ombudsman will ask for some details about you, the date that you first complained to your heat supplier, actions taken by you and the heat supplier, and how you would like your complaint resolved. 

For our Scheme standards to be applied to your complaint, you must have been the heat supplier's customer, a domestic or micro-business consumer, and on a Heat Trust registered heat network when the problem covered by your complaint happened.

If you have specific communication needs, you can let the Energy Ombudsman know by phone on the number above or by emailling This email address is being protected from spambots. You need JavaScript enabled to view it..

Someone else can complain on your behalf as long you send written authorisation to the Energy Ombudsman. This could be a member of your family, a friend, a solicitor, or a volunteer from a body like Citizens Advice. If you nominate a representative, the Energy Ombudsman will communicate with them as if they were you.

The Energy Ombudsman's service is free of charge to consumers; its costs are paid by your heat supplier.

The Energy Ombudsman will take all the circumstances into account to make a fair and impartial decision. They will explain their reasons to you and your heat supplier, and will set out timescales in which any remedy/award is due.

If you accept the Energy Ombudsman's decision, it becomes binding on your heat supplier. If you don't reply to the decision with the specified period, or choose not to accept the decision, then it will not be binding on your supplier.

The Energy Ombudsman will always try to achieve a resolution which is acceptable to both sides, taking account of all available evidence. If, after a resolution is proposed, either party feels that there is an error in fact or has new evidence which was not previously available, it may appeal the decision to the Energy Ombudsman. The Energy Ombudsman will check to see if the outcome is affected by this new information. It will then issue a final decision.

Nothing in the Heat Trust Scheme shall limit your right to take court proceedings against your heat supplier, should the Energy Ombudsman’s decision not be binding on them.

The Energy Ombudsman can ask your heat supplier to apologise, provide an explanation, take action to correct the problem, and/or present you with a financial award. 

No award or remedy will be made against you.

When a heat supplier registers a heat network with the Heat Trust Scheme, they have to sign a contract with the Energy Ombudsman. This contract is known as a Deed Poll. It's enforceable in court, by you or the Energy Ombudsman, in relation to any decision the Energy Ombudsman makes (provided that you accept the Energy Ombudsman’s decision).

Energy Ombudsman decisions aim to put things right, not punish the supplier. The Energy Ombudsman can't dictate how heat suppliers operate or issue fines.