Green Central avatar

Written by

Last updated:

Inspection Hatch for Flue In Void and Gas Safety Regulations

Imagine the possibility of carbon monoxide poisoning lurking within your home due to a faulty gas boiler or flue system.

It’s a bit dramatic, but the consequences can be devastating, even fatal.

The good news is that proper installation and maintenance of inspection hatches, specifically an inspection hatch for flue, can greatly reduce this risk. These seemingly small components play a vital role in ensuring the safety of your gas appliances and flue systems.

But how do you know if your inspection hatch for flue is up to par, and what are the regulations surrounding them? Let’s dive into the world of inspection hatches for flues and uncover the secrets to gas safety.

Hot Deals Icon

Inspection hatches for flues in voids overview

  • Inspection hatches are essential safety features for flue systems in voids, mandated by industry guidance to prevent risks of carbon monoxide poisoning.
  • Building Regulations and Gas Safe requirements must be followed to ensure compliance with inspection hatches.
  • Homeowners and landlords have obligations to maintain gas safety through annual servicing of appliances and inspections by a Gas Safe registered engineer.

Understanding Inspection Hatches for Flues

Inspection hatches, including gas flue inspection hatch, are designed to provide easy access to your flue system, ensuring that your gas appliances are functioning safely and efficiently.

These hatches have become increasingly important since industry guidance mandated their installation for concealed flue systems prior to December 31st, 2012. This was in response to the growing awareness of the risks associated with concealed flues, such as carbon monoxide poisoning.

Why do we Need Inspection Hatches?

Inspection hatches play a pivotal role in the safety of your gas flue system. They allow gas engineers to:

  • visually inspect the entire length of the flue
  • ensure accurate installation
  • detect potential risks
  • adhere to regulations.

If a gas engineer is unable to inspect the full length of the flue, homeowners can decline authorisation to turn off the flue, but they must sign documentation acknowledging responsibility for any potential issues identified in the system during the visual inspection, regardless of the open or closed position of the flue.

Importance of Gas Safety

Gas safety is of paramount importance to prevent carbon monoxide leaks and other hazards associated with gas boilers and flues.

In accordance with Part J Building Regulations, all gas boilers with flues which cannot be inspected in full must be treated as “at risk”, as leaking gas flues can lead to carbon monoxide poisoning.

Installing an access panel in the form of an inspection hatch can help mitigate these risks by having inspection hatches installed, allowing for regular inspections and maintenance.

Building Regulations and Gas Safe Requirements

Understanding building regulations and Gas Safe requirements for inspection hatches is paramount for the safety and compliance of your flue system. The UK Building Regulations dictate that inspection hatches must be 300 x 300mm in size and installed at 1.5m intervals along the flue run to enable physical access and examination.

On the other hand, Gas Safe requirements cover aspects like fitting inspection hatches for flue access, mandatory hatches for room-sealed fan-draught chimneys/flue systems, and the recommended minimum size for hatches.

Building Regulations Compliance

Complying with building regulations is necessary for the safe installation and maintenance of gas flues and inspection hatches. Part J Building Regulations provide guidance on the safety and installation requirements for combustion appliances and fuel storage systems, including air supply, discharge of combustion products, and protection of the building.

Failure to meet these regulations may result in legal action, fines, prosecution, and inspection and enforcement by local authorities.

Gas Safe Registered Engineers

Gas Safe registered engineers are qualified to install and service gas boilers and flues, ensuring safety and compliance.

To become a Gas Safe registered engineer, one must possess a recognised qualification in relation to the areas of gas work they plan to undertake, evidence of competence in gas safety, and complete training and work placements.

It is illegal and highly dangerous to have a non-Gas Safe registered engineer install or service a flue system, as this can lead to serious consequences such as explosions and carbon monoxide poisoning.

Types and Sizes of Inspection Hatches for Flues

There are various types and sizes of inspection hatches available for different flue systems, with materials ranging from stainless steel to high-temperature plastic.

The standard size for inspection hatches is 300mm x 300mm, which allows for adequate access to the flue system for inspection.

Material Considerations

Material selection for inspection hatches is paramount, as it must not negatively affect fire, thermal, or acoustic properties. Stainless steel and high-temperature plastic are the most suitable materials for inspection hatches for flues.

The material of the inspection hatch can have a significant impact on its fire resistance, thermal conductivity, and acoustic properties, affecting its overall performance and durability.

Choosing the Right Size

Choosing the appropriate size of inspection hatch is important based on the requirements of your flue system and building regulations. Part J Building Regulations stipulate that inspection hatches must be 300 x 300mm in size.

This ensures that access points are of an appropriate and safe size. This size allows for adequate access to the flue system for inspection and maintenance, ensuring the safety and efficiency of your gas appliances.

Inspection Hatch Installation Process and Best Practices

Proper installation of inspection hatches is critical for the safety and compliance of your gas boiler and flue system. Following the manufacturer’s instructions and seeking professional advice can help to ensure a smooth installation process.

Safety precautions should be observed during the installation, such as not compromising fire, thermal, or acoustic properties, and ensuring that the hatches provide at least one hour of fire protection.

Gaining Access to the Flue System

Access to the flue system is necessary for adequate inspection and maintenance. Homeowners can access a flue system without the aid of a professional, but it is important to have the necessary tools.

Installing the Inspection Hatch

Proper installation of the inspection hatch ensures safety and compliance with building regulations and Gas Safe requirements.

With inspection hatches fitted correctly, you’ll need tools such as a hacksaw blade or pad-saw, a 7 mm spanner, and a screwdriver for the installation process.

Following installation, a comprehensive inspection should be conducted to verify that all joints and connections are properly secured.

Responsibilities of Homeowners and Landlords

Homeowners and landlords have specific responsibilities regarding inspection hatches and gas safety. Homeowners are responsible for ensuring gas safety in their homes and having their boiler serviced annually by a Gas Safe registered engineer.

Landlords, on the other hand, must arrange an annual gas safety check to be conducted by a registered engineer on all gas appliances and flues/chimneys provided.

Homeowner Obligations

Although homeowners are not legally required to install inspection hatches, they should have their boiler serviced annually by a Gas Safe registered engineer. This helps to ensure the safety and efficiency of their gas appliances and flue systems.

Even without inspection hatches, homeowners should still get their boiler serviced and checked annually by a registered engineer.

Landlord Requirements

Landlords must ensure annual gas safety checks and the safe installation of fittings and flues, with inspection hatches recommended for concealed flues. Failure to comply with these gas safe regulations can lead to severe penalties, including unlimited fines and/or up to six months of imprisonment.

By adhering to these regulations, landlords can protect the safety of their tenants and maintain the integrity of their property.

Tips for Selecting a Reputable Boiler Company Company

Selecting a reputable boiler company is all important to ensure the safe installation and maintenance of your gas boiler and flue system. Check customer feedback or reviews to gain insight into the experiences of past customers, and select a company with an established track record in the industry.

For further information regarding gas flues in voids, you can visit the Gas Safe Register website.


In conclusion, inspection hatches play a vital role in ensuring the safety and efficiency of your gas appliances and flue systems.

By understanding the purpose and significance of inspection hatches, adhering to building regulations and Gas Safe requirements, and selecting a reputable boiler company, you can ensure the safe installation and maintenance of your gas boiler and flue system.

Remember, a small investment in safety today can prevent potentially devastating consequences in the future.

Frequently Asked Questions

What size should flue inspection hatch be?

For optimal safety and access, flue inspection hatches should be 300mm x 300mm. In cases where this is not practical, a smaller size can be fitted.

What is the maximum permissible distance from the edge of an inspection hatch to a flue joint?

It is recommended that inspection hatches be positioned no closer than 1.5m from any flue joint.

What is an inspection hatch?

An inspection hatch is an access panel installed in walls or ceilings, enabling easy access to electrical installations, shafts and interspaces for repair and servicing.

What are the rules for boiler flue in 2023?

In 2023, boiler flue regulations require combustible materials to be a minimum of 18” away from the opening, and it must also be properly sealed in order to avoid any hazardous leaks. All installation and repair work needs to be certified by an authorised professional.

What is the distance between flue inspection hatches?

The distance between flue inspection hatches will vary from property to property, but should be at least 300mm x 300mm and placed within 1.5m of any joint in the flue system.

Green Central avatar

Written by

Read some of our superb solar panel installation reviews from Trustpilot

Recently had solar panels fitted by Green Central and I can’t speak highly enough of the team. The whole experience has been trouble free and I would recommend them to anyone thinking about having solar panels installed – 10/10!

Rob Schofield


Our installation is now complete! 8 solar panels fitted and the journey from initial consultation through to the end product has been seamless.
Hats off Green central, Credit where it’s due.
Will definitely spread the word!



Recently had six solar panels fitted on my house by Green Central and I couldn’t have asked for a better service. In particular, I have to highlight the exceptional communications through out, the over all smooth running process and completely stress free experience, all down to Green Central. I now have grid independence which is valuable beyond estimation.


Name *
Email *
Phone No. *
Post Code *
Name *
Email *
Phone No. *
Post Code *