The Unvented Hot Water Safety Record is for commissioning or inspecting an unvented hot water cylinder. It is your evidence that the cylinder and its safety pipework were left safe, to Building Regulations Part G3. This one is different from the gas certs: it covers a water cylinder, not a gas appliance, so it does not carry the Gas Safe logo. G3 work is certified through CIPHE, BPEC or Logic, a separate ticket from Gas Safe.
When to use this one
- Commissioning a new unvented hot water cylinder (over 15 litres).
- A periodic safety inspection of an existing unvented cylinder.
- Recording the discharge pipework (the D1 and D2 runs and the tundish) on either.
For a gas appliance, use the CP12 or one of the service records instead. For commissioning a whole heating system, the Central Heating Commissioning Certificate fits better. They all sit side by side, so pick whichever matches the job.
Start the record
You can start one two ways:
- From the job. Open the job from Jobs and use the Gas Certificates card. Starting it here links the client, the property and the engineer for you.
- From the Gas Certs page. Go to Gas Certs, tap New certificate, and pick Unvented Hot Water Safety Record.
Fill it in
Work down the form on site:
- Record details. Set the inspection date, pick the engineer, and choose whether this is a Commissioning or an Inspection. There is an advisory line for your unvented hot water competency (your CIPHE, BPEC or Logic certificate). It shows on the record but it does not block approval.
- Client and property. Link the client and the property the cylinder is in.
- Storage vessels and checks. Add the cylinder: location, make, model, serial and heat source. If the cylinder is indirect (heated by a boiler coil), the max primary pressure and flow temperature appear too.
- Operating readings. Record the system pressure, the expansion vessel charge, the relief valve settings and the temperature relief valve. Each reading has a locked unit, and Mucka shows an advisory note if a value looks outside the usual range, but it never overrules you. The result is always your call.
- Safety device tests. Pass or fail the expansion relief valve, the temperature and pressure relief valve, the energy cut-out, the tundish air gap and the immersion thermostat.
- D1 discharge (relief valve to tundish). The D1 length, the number of discharges, and the tundish checks. If more than one discharge feeds the tundish, a manifold size field appears.
- D2 discharge (tundish to termination). The pipe size, material and termination method, plus the three Part G3 acceptance checks: at least 300mm of vertical drop from the tundish, a continuous fall to the termination, and a satisfactory termination point.
- Result. Mark each cylinder safe to use or not safe. A cylinder that is not safe, or any failed safety or D2 check, makes the record a fail.
- Declaration. Record the overall result, add an observation and a recommendation if you have them, set the next inspection date, and sign on screen. 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:
"Start an unvented hot water safety record for the cylinder 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.