The joy of being a Heating Engineer

Gas Council Numbers identify appliances and parts. Here’s a reminder of how the system operates.
The appliance indexing system was first introduced from 1930. Originally a different number was issued for each variant of an appliance type.

Little has changed over the years, but recently more appliances are being introduced with fewer variants as manufacturers use common parts 
across a range of appliances. This helps reduce the confusion of pinpointing specific appliances where minorvariants may exist. For example, in 
the past where a fire manufacturer may have produced one heat engine and several different fire fronts, these would have been categorised and labelled as individual appliances and a separate Gas Council Number would have been issued for each.

Today one G.C. Number can cover a multiple of appliance types utilising one heat engine, with each fire front having seperate part coding under 
the one appliance G.C. Number.

What the numbers mean

The G.C. Number consists of seven digits set out thus: 00-000-00.

The significance of the digits is as follows.

First two digits 
a) The first digit specifies the main type of appliances. For example: 
1 – cooking appliances 
4 – central heating appliances 
5 – water heating appliances 
b) The second digit specifies the type of appliance within the type. For example: 
11 – domestic cookers, including split-level and built-in, with integral ignition 
12 – domestic cookers including split-level and built-in without integral ignition. 
41 – central heating boilers (conventional). 
44 – central heating boilers (back boilers). 
51 — instantaneous sink and large water heaters. 
52 – instantaneous multipoint water heaters 
Next three digits 
The next three digits stand for the name of the manufacturer. For example: 
077 – Baxi Heating 
811-Valor Heating 
Last two digits 
The last two digits cover the model. For example: 
50 – Bermuda 552 
If an appliance manufacturer has made more than 98 appliances within a type they will be given a second series of three digits to cover their name.

Example of complete number

44-077-50: Central heating, back boiler 
-Baxi – Bermuda 552.