Section 4 - Electric heating systems

This section provides guidance on the specification of fixed electric heating systems for dwellings.

4.1 - Scope of guidance

The guidance given in this section covers the following types of fixed electric heating systems:

Electric boilers serving central heating systems.
Electric warm air systems.
Electric panel heaters.
Electric storage systems including integrated storage/direct systems

Portable, plug-in appliances are not covered by the Building Regulations or by this guide.

Where appropriate, it may also be necessary to refer to the other sections in this guide covering underfloor heating and solar water heating.

4.2 Electric boilers serving central heating systems in new and existing dwellings

This section provides guidance on the specification of electric boilers serving wet central heating systems for dwellings.

Terminology and applicability of guidance to different scenarios in new and existing dwellings

The guidance in this section applies to the following situations:

The specification of central heating systems in new dwellings – this situation is referred to in this section as a new system.
The specification of central heating systems in existing dwellings where previously space heating was not provided by central heating – this situation is also referred to in this section as a new system.
The specification of a replacement central heating system and/or component in existing dwellings where central heating is already installed – this situation is referred to in this section as a replacement system.

In situations (a) and (b) above the guidance for compliance of new systems (in new and existing dwellings) with Part L is the same.

In situation (c) above, that is for replacement systems in existing dwellings, in most cases the guidance for compliance with Part L is as for new systems, unless otherwise stated in the relevant section.

Electric boilers serving central heating as new systems or replacement systems in dwellings should meet the following conditions:

The minimum provisions for system circulation as given in Table 12 (row a) should be met.

AND

The minimum provisions for system preparation and water treatment as given in Table 12 (row b) should be met.

AND

The system should be commissioned in accordance with the minimum provisions given in Table 12 (row c).

AND

The minimum provisions for boiler interlock, zoning and time control and temperature control of the heating and hot water service circuits as described in Table 12 (row d) should be met. An acceptable alternative to these is any boiler management system that delivers the specified zoning, timing and temperature (and, if applicable, boiler interlock) control provisions. When electric boilers are installed as replacement for existing boilers, the minimum level of system controls should be installed, as described in Table 12, unless they are already installed and fully operational. If an individual component of the control system is being replaced in an existing system, for example a room thermostat, it is not necessary to upgrade the system to meet the minimum requirements.

AND

The minimum provisions for hot water storage and labelling of storage vessels as given in Table 13 need to be met.

AND

Pipework should be insulated as described in Table 14.

Table 12

Tables 12A & 12B

Table 13

Table 13

4.3 - Electric heating systems (other than central heating using electric boilers)

The guidance given in this section covers the following types of fixed electric heating systems:

Electric warm air systems.
Electric panel heaters.
Electric storage systems including integrated storage/direct systems.

Portable, plug-in appliances are not covered by this guide.

Fixed electric heating systems (other than electric boilers) in new and existing dwellings should meet the following conditions:

Electric warm air systems should meet the minimum requirements for zone control and time and temperature control of the heating system as set out in Table 15 (row a).
Panel heaters should meet the minimum requirements for local time and temperature control of the heating system as set out in Table 15 (row b).
Storage heaters should meet the minimum requirements for charge control and temperature control of the heating system as set out in Table 15 (row c).

In existing dwellings, new or replacement storage heaters should have a heat retention not less than 45 % measured according to I.S. EN 60531:2000. They should incorporate a timer and electronic room thermostat to control the heat output that are user adjustable.

Table 14

Table 14A

Table 15

Table 15A

4. Electrical heating systems