# Record a gas tightness test and purge Source: https://help.mucka.ai/gas-certs/record-a-tightness-test-and-purge Category: Certificates Last updated: 2026-08-18 > Log a Gas Testing & Purging Record for strength testing, tightness testing and purging of a gas installation. Pick the procedures you carried out and only those test sections show, then send it as a PDF. The Gas Testing & Purging Record is for testing and purging a gas installation, not for inspecting appliances. Use it when you strength test, tightness test or purge the pipework, for example before commissioning a new install or recommissioning an existing one. It records the readings you took and the result you called, then hands the customer a clear PDF of the work. ## When to use this one - A tightness test on a domestic installation (IGEM/UP/1A). - A strength test, tightness test and purge on a larger installation (IGEM/UP/1). - Any standalone gas test or purge that needs a record, on its own or as part of a bigger job. This is a test record of the installation, so it has no appliance list. If you are inspecting appliances for a landlord, use the CP12 instead. If you are servicing an appliance, the Boiler Service Record or Service & Maintenance Record fits better. They all live side by side, so pick whichever matches the job. ## Start the record You can start one two ways: 1. **From the job.** Open the job from [**Jobs**](/jobs) and use the **Gas Certificates** card. Starting it here links the client, the property and the engineer for you. 2. **From the Gas Certs page.** Go to [**Gas Certs**](/gas-certs), tap **New certificate**, and pick **Gas Testing & Purging Record**. ## Fill it in Work down the form on site: - **Test details.** Set the test date. The engineer's and the workspace's Gas Safe numbers are checked here, since every gas record carries them. - **Client and property.** Link the client and the property the work covers. - **Work undertaken.** Pick every procedure you carried out: **Strength test**, **Tightness test** or **Purge**, in any combination. Only the test sections you choose appear below, so a tightness-only job never asks you for the strength fields. - **Strength test.** Method, installation type, test medium, the strength test pressure, durations, the permitted drop and the actual drop, then the result you call. - **Tightness test.** Gas type, meter details, the installation volume, the tightness test pressure, the let-by and test durations, the maximum permitted leak or drop, and the actual drop and leak rate, then the result. There is a yes/no for whether the weather or temperature could affect the test, so a marginal result has the conditions recorded alongside it. - **Work out the installation volume instead of typing it.** Tap **Work it out** next to the total installation volume. Tell it the meter and the pipe runs and it fills the volumes in for you, plus the maximum pressure drop you are allowed for that volume — all to IGEM/UP/1B Edition 4, the edition that becomes the only one from 1 October 2026. Full walkthrough: [Work out installation volume and purge volume](/help/gas-certs/work-out-installation-volume). - **Purge.** A pre-purge safety checklist (risk assessment, signs, persons advised, bonding and so on), the purge volumes, the final oxygen or LFL reading, and the result. The same **Work it out** sits next to the total purge volume, and one calculation fills the tightness and purge figures together, so you only enter the pipework once. - **Pressures use a locked unit.** Tap the unit to switch between mbar and bar so a reading can never be read as the wrong scale. Mucka shows an advisory note if a reading looks outside the usual range, but it never overrules you: the result is always your call. - **Declaration.** Record the overall result, add any comments, and sign on screen. If the installation was left unsafe, note the Warning Notice serial in the comments. The customer can sign for receipt too, but they do not have to. Everything saves as you go, so you can put your phone down mid job and pick up where you left off, even on a different device. ## Approve and send Tap **Approve** when it is done. Mucka shows you the outcome and asks you to confirm. Approving **locks the record as a legal document** and generates the PDF. After that it cannot be edited, only corrected. Then tap **Send**. Mucka pre-fills the recipient and attaches the PDF. Check the message, then send. ## Need to fix an approved record? You cannot edit a locked record, but you can **create a correction**. That copies it into a fresh draft with a new serial number; once you approve the correction, the original is marked superseded and its PDF carries a "superseded" watermark. The original is never deleted. ## Ask Mucka You can ask Mucka to get one started for you: > *"Record a tightness test and purge for the install at 88 Bradford Road."* Mucka opens the draft and links it up, but it never approves or sends a record on its own. Filling in the readings, approving and sending are always your call.