A serial number consists of 28 characters, starting with the number 21 and ending with the letter ‘N’ followed by a single other number.

Where to find your serial number on your boiler – You will usually find the serial number underneath your boiler or on the control panel

Where to find your serial number on your heat pump – Your serial number can be found with on the back of the outdoor heat pump unit or on the back of the control box of the indoor unit.

The serial number for your heating appliance should also be included in your benchmark logbook.

We will repair any eligible Vaillant boiler unless it is uneconomical to do so. In which case, we will provide advice on a suitable product to replace the boiler. If you are a Repair & Care customer and we are not able to repair your boiler or we decide that it is beyond economical repair after the initial repair, Domestic & General will arrange for your boiler to be replaced with a new one, up to the value of £750. Installation and associated costs are not included. Our repair services do not cover larger commercial range of boilers: Vaillant ecoTEC 45kW to 280kW models. Find out more here.

You can take out a plan for any boiler less than 8 years old.

Once you have entered into a maintenance plan, this will renew automatically year after year with no cap on the appliance age.

Combination boilers are typically the most popular boiler and are compact with no separate hot water cylinder or cold water storage tank.

System boilers require a separate hot water cylinder (usually found in an airing cupboard), and are usually found in larger homes with multiple bathrooms.

Regular boilers require both a hot water cylinder and cold water storage tank (usually found in the loft), and are usually present in homes with older radiator systems.

If you're still unsure what kind of boiler you have, your local installer will be able to advise you.

Your Vaillant guarantee covers you for the repair of any defects related to the manufacture of your Vaillant appliance. The repair has to be completed by one of our Vaillant Service Engineers and will cover both parts and labour. Find out more here.

Our Maintenance and Support plan offers 12 Month protection for your heating system. In partnership with Domestic and General Services Limited, these plans are designed to provide maintenance for your boiler and controls include:

• Annual servicing
• Exclusive access to our Boiler Care portal
• A dedicated contact centre, available 7 days a week, 364 days a year
• Repairs up to the value of £1,500
• Hints and tips to maintain your boiler

You can also renew this plan annually to help protect your boiler for longer.

You can submit your question here or you can call us on: 0330 102 8573