What does this unit heater annual checklist cover?

15 items across 5 sections, covering isolation before service, heat source, venting on gas units, mechanical and controls, and more. 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 HVAC service tech, with a gas fitter's combustion check on gas-fired units.

When in the schedule should this walk happen?

Once a year ahead of the heating season, so the burner, flue and safeties are proven before the units run unattended all winter.

Why do these items ask for a photo?

9 of the 15 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 an unit heater annual inspection?

Gas heat exchanger cracked from years of thermal cycling and spilling combustion products into the space, never caught because it was only ever checked cold. Flue joints on a gas unit pulled apart or corroded at the draft hood, so products spill instead of venting, found only when someone smells it. Hydronic coil half-blocked with air or sludge and cutting output, blamed on an undersized unit instead of being purged and cleaned.

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

Unit heater annual maintenance checklist

The annual unit heater 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 IMC, 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.

Isolation before service

Unit locked out and tagged at every energy source
Disconnect locked and the gas cock or coil valves closed and tagged; firing and safety tests run under the procedure's temporary release (panels on, clear, locks off by their owner), then re-locked.
Heat source cooled and pressure relieved before opening
Heat exchanger or elements left to cool, and on hydronic or steam units the isolated coil bled down so no hot water or steam escapes when it is opened.
No photo

Heat source

Gas burner, heat exchanger and combustion inspected
Heat exchanger checked for cracks and corrosion, burner ports clean, combustion and gas pressure verified against the rating plate on gas units.
No photo
Hydronic coil and connections serviced where fitted
Coil clear of air and debris, no weeping at unions or the control valve, heat output confirmed after purging on hydronic units.
No photo
Heating surface cleaned of dust, soot and scale
Going past the quarterly look: flue passages brushed on gas units, element sheaths wiped on electric units, coil fins blown or washed clean on hydronic or steam units.
Steam trap and condensate return tested on steam units
Trap cycles and passes condensate without blowing live steam, strainer cleaned, return line not waterlogging the coil or hammering on start.
No photo

Venting on gas units

Flue and draft hood inspected end to end
Vent connector pitched up, joints sound and corrosion-free, draft hood clear, spillage checked at the hood with the unit firing.
No photo
Vent terminal and roof or wall penetration inspected
Cap on and clear of nests and debris, flashing or wall seal intact, terminal clearances to air intakes as the vent manufacturer's instructions set.
No photo

Mechanical and controls

Fan motor and bearings serviced
Motor bearings checked for play and noise, lubricated per the schedule, fan blade clean and balanced, mounting hardware retightened.
Safety limits and controls tested
High-limit, fan control and any flame-safety or lockout function exercised, unit shuts down correctly on a simulated fault.
Fan blade hub and guard fasteners tightened
Blade set screw snug on the shaft flat, guard fastened at every point with no gap a hand fits through, blade tips clear of the guard when turned by hand.
Thermostat checked against a reference thermometer
Stat reading compared with a reference thermometer beside it, calibration, setpoint and differential adjusted to the manufacturer's instructions.

Return to service

Panels and guards on, locks removed by whoever hung them
Access panels and fan guard refastened, tools out of the cabinet, each lock and tag removed by the person who applied it under the site's procedure.
Unit restarted and run through a full heating cycle
Heat source reopened, unit called on by the stat, heats, satisfies and shuts off cleanly, with the fan running on until the residual heat is purged.
Fan motor amps read with the unit called on again
Fan motor amps read at its leads under the energized-work procedure and PPE with the unit called on again, against the motor nameplate and last season's value to catch a dragging bearing.

What usually sends this back

The failures are almost always the evidence, not the work

Gas heat exchanger cracked from years of thermal cycling and spilling combustion products into the space, never caught because it was only ever checked cold.
Flue joints on a gas unit pulled apart or corroded at the draft hood, so products spill instead of venting, found only when someone smells it.
Hydronic coil half-blocked with air or sludge and cutting output, blamed on an undersized unit instead of being purged and cleaned.

Verified against

IMC (mechanical code)

Common questions

6 answers

What does this unit heater annual checklist cover?: 15 items across 5 sections, covering isolation before service, heat source, venting on gas units, mechanical and controls, and more. 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 HVAC service tech, with a gas fitter's combustion check on gas-fired units.
When in the schedule should this walk happen?: Once a year ahead of the heating season, so the burner, flue and safeties are proven before the units run unattended all winter.
Why do these items ask for a photo?: 9 of the 15 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 an unit heater annual inspection?: Gas heat exchanger cracked from years of thermal cycling and spilling combustion products into the space, never caught because it was only ever checked cold. Flue joints on a gas unit pulled apart or corroded at the draft hood, so products spill instead of venting, found only when someone smells it. Hydronic coil half-blocked with air or sludge and cutting output, blamed on an undersized unit instead of being purged and cleaned.
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.