Gas Testing Amendments st October 2026 – IGEM/UP/1B Edition 4
The change that took effect on 1 October 2026 is IGEM/UP/1B Edition 4, the standard for tightness testing and direct purging of small gas installations. IGEM published it in March 2026. Edition 3 stayed available until it was withdrawn on 30 September 2026, and Edition 4 has applied in all cases from 1 October 2026. Gas Safe Register’s ISU 133 Edition 2, issued 15 April 2026, confirms that Edition 4 is now mandatory
Shelford Heating have always applied a test to the Gas System when undertaking Service Works (at Start and Finish) , as there is a potential for us to disturb or break the Gas Train Assembly – and always applied a Zero Loss to Gas Supply Pipework only, having already isolated Appliances, and any systems failed we have undertaken to supply a cost to replace a gas service to ensure a minimal distruption to Heating and Hot water.
With a sound Gas Supply, Recording of the Potential Volume of Gas against a table will give Permissable drop in pressure but these new Rules are Based on Actual as opposed to a nominal calculation based on the meter size.
| Fuel gas | Installation Volume (IV) (m3) | Maximum permissible pressure drop (mbar) |
|---|---|---|
| LPG/Air (Table 2) | ≤0.025 >0.025 – ≤0.035 |
1.5 0.5 |
| Natural gas (Table 3) | ≤0.005 >0.005 – ≤0.010 >0.010 – ≤0.015 >0.015 – ≤0.035 |
8 4 2.5 1 |
| LPG (Table 5) | ≤0.0025 >0.0025 – ≤0.005 >0.005 – ≤0.01 >0.01 – ≤0.035 |
2 1 0.5 No perceptible movement |
The Safest Solution on a system with a Leak to an appliance is to Make safe, Isolate the item or attempt a repair if practicle and able within a sensible time.
We never want to shut any service off in Full, but if we must for safety then we will.