# Record a power flush

Source: https://help.mucka.ai/gas-certs/record-a-power-flush
Category: Certificates
Last updated: 2026-11-09

> The Central Heating Cleansing Record for a power flush or chemical clean to BS 7593. TDS readings before and after, each radiator's valve settings, the cleaner and inhibitor you used, and your water test results.

The Central Heating Cleansing Record is the paperwork for a power flush, or any clean of a wet heating system: what state it was in, how you cleaned it, the readings that show it worked, and the inhibitor you left in it. It follows the cleansing record pads the trade has used for years, and BS 7593, the standard for cleaning and treating central heating water.

Find it under **New certificate**, on the Gas tab, in the **Servicing** group as **Central Heating Cleansing Record (Power Flush)**. To have your power flush jobs offer it in one tap, open your power flush job type in [**Settings → Work → Job types**](/settings/work/job-types) and pick it as the certificate that job type produces.

## It is not a gas document

You will not be asked for a Gas Safe number and none prints. Flushing a heating system is not work on a gas fitting, and you might be doing it on an oil or LPG system just as well.

## What the form asks

It follows the job in order:

1. **The system.** The boiler's make, model and serial, roughly when the system went in, what kind of system it is, how many radiators, the pipe size at the boiler, the water content, the metals in it and any treatment already in there. If you have not measured the water content, allow about 10 litres per single radiator, or per kW of boiler output.
2. **The clean.** Why it needed doing, the type of cleaning (power flush, power flush and chemical, manual flushing and chemical, or mains water only), the cleaner and its concentration if you used one, the inhibitor and its concentration, and whether a permanent in-line filter is fitted.
3. **TDS readings.** The mains water, the initial purge with every radiator open, and the final flush with every radiator open.
4. **Radiators.** Add one for each radiator you flushed on its own: where it is, how many turns the lockshield was open, where the TRV was set, and the TDS with it open. The valve settings are there so you can put the balancing back afterwards.
5. **Water test kit results.** Hardness, pH, chloride, copper and iron, each for the supply water and the system water.

## Fill it in by talking

Tap **Start listening**, put the phone down and say it as you go. A few things worth knowing:

- Say each TDS reading with its stage: "mains TDS two ten", "initial purge fourteen fifty", "final flush two twenty five".
- "Add the lounge" adds a radiator and moves onto it. Then "TDS two forty, lockshield one and a half, TRV four" goes on that radiator. Say "radiator two" or its room to go back to one.
- For the water test kit, name the water first: "supply water, hardness two forty, pH seven point four", then "system water, copper two, iron three".

Anything that looks misheard waits for a tap, and you still sign by hand.

## What you need before you can approve

The type of cleaning, the mains TDS, the final flush TDS, the inhibitor that went in, and your signature, plus the cleaner if the method used one. Everything else is optional, and Mucka will mention anything useful you left blank (a missing initial purge reading, for example) without stopping you.

Mucka will not tell you a TDS reading is too high. Different manufacturers and guides give different figures for a clean system, so you record what you measured and you make the call.

## What comes out

One landscape page: your business, the job address and who it is issued to, the mains, before and after TDS in the top corner, the job details, the radiator table, the water test results, your comments and both signatures. Approve it and Mucka gives it a serial (CHCR-0001 and on), renders the PDF and offers to email it.

There is no pass or fail on this record, and no renewal reminder. A power flush is a one-off; the yearly inhibitor check is done at the boiler service.