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Free checklist

Expansion tank annual maintenance checklist

The annual expansion tank service is the deep pass: the measurements, cleanings and tests a quarterly round doesn't reach. This checklist keeps the full service on record with the photos that make it defensible later. Work is commonly verified against manufacturer's published instructions. Confirm the edition your authority having jurisdiction has adopted.

Items
4
Photos required
6

Who runs it

The plumbing service tech on the annual service, with the tank isolated and the water side relieved so the pre-charge can be read cold.

When in the schedule

Once a year, the only pass where the tank is actually isolated and gauged rather than judged by tapping, and re-charged to match the current system pressure.

The checklist

Every item, and the photo that proves it

The photo count on each row is what RTI would require before the item can be submitted. Copy the list as is, or load it into RTI and let the gate enforce it.

01

Pre-charge

  • Tank isolated and water side relieved before gauging

    Tank valved off from the system and its water pressure bled down so the air pre-charge is read with no system pressure fighting the gauge.

    2 photos
  • Pre-charge set to the system fill pressure

    Air pre-charge measured and adjusted to match the system's cold fill pressure at that location per the published instructions, then re-checked after adjustment.

    1 photo
02

Bladder integrity

  • Bladder proven intact under charge

    Air valve holds the set pre-charge and blows clean air with no water, confirming the bladder is separating air from water rather than passing it.

    1 photo
03

Shell, connection and air vent

  • Shell, tapping and any air vent serviced

    Shell and seam free of corrosion under a close look, connection re-sealed and supported, and any automatic air vent on the tank tapping proven to seat and not leak.

    2 photos

What usually sends this back

The failures are almost always the evidence, not the work

  • Pre-charge read with system pressure still on the tank, giving a meaningless number and leaving the tank set wrong for another year.
  • Tank re-charged to a generic figure instead of the actual system fill pressure at that tank's height, so it still can't take up expansion properly.

Run it with the Photo Gate

A checklist nobody can submit half-finished

Load this list into RTI, stick a QR tag on the area it covers, and the submit button stays locked until every mandatory item is answered and the 6 required photos exist. Approved walks roll into a branded turnover package with a tamper-evident record behind every line.

Submission state

Mandatory items answered4 of 4
Photos attached3 of 6
Submit locked, 3 photos missing

The gate is enforced on the server, so it holds even if the phone is offline when the walk happens.

Common questions

What does this expansion tank annual checklist cover?
4 items across 3 sections, covering pre-charge, bladder integrity, shell, connection and air vent. Each item spells out what the person walking the job is actually looking for, not just a box to tick.
Who should run this inspection?
The plumbing service tech on the annual service, with the tank isolated and the water side relieved so the pre-charge can be read cold.
When in the schedule should this walk happen?
Once a year, the only pass where the tank is actually isolated and gauged rather than judged by tapping, and re-charged to match the current system pressure.
Why does every item ask for a photo?
6 of the 4 items call for photo evidence. A checklist answer without the photo is a claim; the photo is what makes the record worth something in a dispute and lets a reviewer approve work without re-walking the job.
What most often fails a expansion tank annual inspection?
Pre-charge read with system pressure still on the tank, giving a meaningless number and leaving the tank set wrong for another year. Tank re-charged to a generic figure instead of the actual system fill pressure at that tank's height, so it still can't take up expansion properly.
Can I use this checklist in RTI?
Yes. Start a free RTI workspace, build this list as a checklist, and the Photo Gate holds the submit button until every mandatory item is answered and its photos are attached. Approved inspections roll into a branded turnover package with a tamper-evident audit trail.