What does this tankless water heater quarterly checklist cover?

14 items across 4 sections, covering water side, combustion and venting, supply and diagnostics, return to service. 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 or maintenance tech on the quarterly mechanical round.

When in the schedule should this walk happen?

Every quarter, since a tankless unit gives no warning before it starts short of temperature or throws a fault mid-shift.

Why do these items ask for a photo?

9 of the 14 items call for photo evidence, 10 photos in all. 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 tankless water heater quarterly inspection?

Inlet filter screen never pulled, so it clogs with debris and the unit modulates down or faults on low flow, read as a failing heater. Delivered temperature judged at the unit's display instead of a fixture, so the drop across a long run to the far tap goes unnoticed. Error and fault history never read off the controller, so a unit clearing repeated ignition or scale faults on its own is treated as healthy.

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.

Free checklist

Tankless water heater quarterly maintenance checklist

A quarterly tankless water heater round is short on purpose: it catches the wear items that fail between annual services. This checklist is sized for a tech with a phone. Every item says what to look at and the photo that proves the round happened. Work is commonly verified against IPC / UPC plumbing codes, manufacturer's published instructions. Confirm the edition your authority having jurisdiction has adopted.

Start free with this checklist Download as PDF

The checklist

Every item, and the photo evidence it needs

The photo count on each row is what RTI would require before the item can be submitted. Work the list here and watch the gate hold, or load it into RTI and let it enforce the real thing.

Water side

Unit locked out and water isolated before the screen is pulled
Every circuit feeding the unit locked and tagged, cold and hot isolation valves shut and pressure bled at the drain port. Screen back in and valves open before locks come off, by whoever hung them.
Inlet filter screen removed, cleaned and reseated
Cold inlet screen pulled, flushed of grit and scale, reinstalled and confirmed not restricting flow into the heat exchanger.
Occupants told before outlet temperature is tested or changed
People using fixtures on this heater told before a test draw or a setpoint change, and the setpoint left at its recorded value unless the owner approved a change.
No photo
Delivered temperature verified at a fixture
Actual temperature measured at a representative fixture, compared against the setpoint, checked that a hot draw holds temperature and doesn't run cold-hot-cold.
Flow and temperature rise read against the rating
At a steady full draw, flow and inlet and outlet temperatures read on the controller or measured, the rise compared with the manufacturer's flow chart and the last visit.
Unit and connections checked for leaks
No weeping at inlet/outlet unions, isolation valves or the relief line, no mineral trails on the case pointing to a slow internal leak.

Combustion and venting

Venting and condensate drain checked on condensing units
Vent run intact and sloped, terminal clear, condensate trap primed and neutralizer (where fitted) draining freely, not backing up into the unit.
No photo
Burner flame and ignition observed
Clean ignition on demand, steady flame with no rollout or sooting, unit modulating smoothly rather than hunting.
No photo
Service clearances and air openings kept clear around the unit
Nothing stored against the case or service side; on gas units the combustion air intake and any room air openings are free of lint, debris and nests.

Supply and diagnostics

Gas or electric supply confirmed adequate
Gas pressure holding under full fire, or electrical connections tight and undamaged on electric units, no scorching at the supply terminals.
Error and fault history read off the controller
Stored fault codes reviewed and logged, recurring ignition, flow or scale faults noted as a trend rather than cleared and forgotten.
Linked units checked sharing load in a cascade
Where units run as a cascade or rack, each one fires as demand rises, the lead rotates as set, and no unit sits faulted while the others carry the load.
No photo

Return to service

Unit left heating on demand with no active fault showing
Locks confirmed off by the people who hung them, a hot draw starts the unit, and the display or status light shows no active fault when the tech leaves.
Quarterly readings added to the unit's service record
Flow, temperature rise, fault codes and screen condition recorded against the unit tag so the descale interval can be judged from the trend.
No photo

What usually sends this back

The failures are almost always the evidence, not the work

Inlet filter screen never pulled, so it clogs with debris and the unit modulates down or faults on low flow, read as a failing heater.
Delivered temperature judged at the unit's display instead of a fixture, so the drop across a long run to the far tap goes unnoticed.
Error and fault history never read off the controller, so a unit clearing repeated ignition or scale faults on its own is treated as healthy.

Verified against

IPC / UPC plumbing codes

Common questions

6 answers

What does this tankless water heater quarterly checklist cover?: 14 items across 4 sections, covering water side, combustion and venting, supply and diagnostics, return to service. 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 or maintenance tech on the quarterly mechanical round.
When in the schedule should this walk happen?: Every quarter, since a tankless unit gives no warning before it starts short of temperature or throws a fault mid-shift.
Why do these items ask for a photo?: 9 of the 14 items call for photo evidence, 10 photos in all. 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 tankless water heater quarterly inspection?: Inlet filter screen never pulled, so it clogs with debris and the unit modulates down or faults on low flow, read as a failing heater. Delivered temperature judged at the unit's display instead of a fixture, so the drop across a long run to the far tap goes unnoticed. Error and fault history never read off the controller, so a unit clearing repeated ignition or scale faults on its own is treated as healthy.
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.

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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 10 required photos exist. Approved walks roll into a branded turnover package with a tamper evident record behind every line.