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  • Writer's pictureJames Flemington

Part L Regs & You: 3 need to know facts

Updated: Apr 14

Government building regulations sounds like a very dry subject…and it is.

But there are some important changes that you should know if you do any work on your heating system.

Part L regs (conservation of fuel and power) were updated in June 2022. They formed part of a wider government strategy to reduce UK carbon emissions and reach net zero by 2050. #partl


But what does this mean for us?

We work mainly is existing properties, like yours. The UK has a large proportion of older housing stock and it’s quite likely your house is 50 years old, if not older.

In order to reduce domestic CO emissions the onus really falls on heating engineers when working in your home. Which is why it’s so important you have a quality engineer!


1. The appliance should be appropriately sized for the heat loss of the property

In other words, you need a heat loss survey. A heat loss survey is conducted room by room, measuring all dimensions, windows and doors, logging room position in relation to the outside and internal rooms and the fabric make up of the building.

Building loose heat depending on its type of construct, materials and how cold it is outside.

A heat loss survey is the absolute first step you must take before moving on to radiator or boiler sizing. Once you have a whole house calculation you can accurately size the boiler…which leads on to pipe and pump sizing.

The days of inspired guess work are over. Hence why it’s vital a competent engineer takes care of this for you. Your average plumber hasn’t got a clue and neither does a normal gas man.

Inaccuracy at this sage will lead to inefficient or inadequate heating.

This will waste your money either on unnecessary labour, materials and most definitely energy bills.

We conduct surveys to the process set out by CIBSE (Chartered Institute of Building Services Engineers


2. Complete new installations need to be designed to run at a max flow temperature of 55 degrees

Basically your heating needs to run cooler than it used to. This does not mean your house will be colder!

That is the point of the heat loss survey. It leads on to accurate radiator sizing which means each room receives the amount of heat you want.

You probably have a condensing gas boiler in your house. Most people do. They were designed to run at a 70 degree flow temperature, losing 20 degrees through the radiators and returning at 50 degrees.

This was so the return water helped condense the flue gasses. In turn retrieving latent heat from the phase change of water value to liquid water in the heat exchanger.

However, most UK boilers do not condense as they were not set up correctly! You can thank Mr Average Plumber for that.

We’ve had decades of efficiency wastage. Heating engineers know it, the government know it…it’s just you and the average install that didn’t.

The government is implementing low temperature heating. It’s a step on the way to Air Source and it’s the future of domestic heating.


3. All systems must be commissioned to BS7593


Simply put your engineer needs to make sure your system is clean, has filters installed to keep in clean and monitor your system during services.

I’ve yet to meet a plumber or gas man that’s even heard of these requirements. Let alone carries them out.

We check levels of inhibitor, corrosion and pH during every service. It’s quick and easy! There’s no reason why every service doesn’t include this!


Most installers will run some chemicals through your radiators to give them a quick clean. This is the bare minimum. If you have an existing system it should ideally be completely flushed to get all the dirt, chemicals and corrosion from the system.

No one would buy a new car and put their old engine oil in it. Yet most of us do.

System filters should be installed on all new installs. These help prevent build ups of sludge in the boiler, which will hamper its efficiency. These are relatively cheap, easy to install and form part of the manufacturers warranty requirements.

Most of us want to help reduce excess carbon emissions. The government has set guidelines to help us achieve it.

All you have to do is make sure you get the right engineer!


#partl #energyefficiency #lowcarbon #lowtemperature #heating #engineer #hydronics #heatpumps #essex






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