Pump prime mode, by oil primary control

Technician reference

This page is for the technician at the burner. Pump primeprimeGetting oil flowing through the pump and out the nozzle on a dry or air-bound line, done at the pump's bleed port. runs the burner with the flame sensor ignored, or with the trial for ignition stretched, and the whole point of the mode is to push oil and air out of the pump while the motor runs. A homeowner’s part of a run-out is on the bleeding page. Everything below assumes a licensed technician, a combustion chamberfireboxThe lined chamber where the oil actually burns. Its refractory liner holds the heat and protects the walls. that is free of oil and oil vapor, and a burner that has not been resetresetThe button that clears a lockout for one more ignition attempt. Press it once only, never repeatedly. over and over first.

What pump prime does

A primary controlprimary controlThe small box on the burner that runs the ignition sequence, watches the cad cell, and latches into lockout on a failed start. gives the burner a short trial for ignition, then locks out if it sees no flame. That is the right behavior on a normal start and the wrong behavior when the pump is full of air after a run-out, a filter change or a pump change. The old way around it was to jumper the cad cellcad cellThe light sensor that proves a flame is burning. If it cannot see flame fast enough, the primary control locks the burner out. so the control thought it saw flame. Pump prime replaces the jumper.

Two designs hide behind the one name.

• A dedicated state with its own timer. Beckett GeniSysGeniSysBeckett's modern oil primary control. It reports its state with status lights (red, green, yellow) rather than a blink count. and Carlin controls step into a pump prime state where the motor and the igniterigniterThe modern solid-state replacement for the ignition transformer, doing the same job of firing the spark. run, the valve is energized where the control has one, and a separate clock runs. On the Beckett controls the cad cell is ignored for the whole state.
• A stretched trial for ignition. The Honeywell R7284 and R7184R7184A Honeywell/Resideo oil primary control. One light shows its mode by flash rate, and a separate flash count reads the cad cell's strength. keep their normal cycle and add time to the trial, with the igniter held on. The cad cell is still watched, so the burner can light and go to run in the middle of the routine, or lock out when the added time runs out.

The distinction matters at the bleedbleedPurging air from the oil line at the pump's bleed port so the burner can draw fuel again, usually after a run-out. port. On a dedicated state the burner will not go to run while you bleed. On a stretched trial it can.

Before you start

• The chamber must be free of oil and oil vapor. Every manufacturer prints this above its starting and resetting instructions, and it is the one warning that covers pump prime.
• Put a clear hose on the bleed port and run it into a container, then open the bleed port fully before entering the mode. With the port open the oil comes out the hose instead of spraying through the nozzlenozzleThe precision tip that atomizes oil into a fine spray for burning. It is sized by flow rate, spray angle, and pattern. into a hot chamber. A gauge in the nozzle port does the same job.
• Bleed until the oil runs with no froth and no bubbles. Air left in the line is what makes an unstable fire, a hot gas puff-back and heavy smoke on the next start.
• Know the time limit of the control in front of you. They run from one minute to ten, and a control that times out drops back to standby or locks out.
• Repeated resets are the other way oil ends up in the chamber. The restricted and hard lockouts exist to stop that, and clearing one is a technician’s reset with the cause found first.

Time limits at a glance

Beckett GeniSys 7505

Three lights: a red one in the reset button, a green flame light and a yellow pump prime light. Pump prime is entered with an arming hold and then a click.

1. Hose on the bleed port, port fully open, container under it.
2. Start a call for heat and let the burner start.
3. After the burner starts, hold the reset button for 15 seconds until the yellow light comes on. The yellow light means the hold was long enough. The burner is off while the button is held.
4. Release the button. The yellow light goes out and the burner starts again.
5. On that start, while the igniter is still on, click the reset button once. The control goes into pump prime. Motor, igniter and valve run for four minutes with the yellow light on and the cad cell ignored.
6. Bleed until the oil runs clean.
7. At four minutes the yellow light goes out and the control returns to standby by itself. If the pump is not primed yet, click the button again on the next start and repeat.
8. End the call for heat.

To leave early, end the call for heat or hold the button for at least one second. Two things share the same hold: 15 seconds on the button is also the reset from a hard lockoutlockoutThe safety state the primary control latches into after a failed start. It stops the burner until someone presses reset., and the yellow light means either pump prime or a button that has been held past 15 seconds, so read the state of the burner, not the light alone.

Beckett GeniSys 7565 and 7585

Same sequence as the 7505, with the ACTION button in place of the reset button and the SYS light in place of the yellow light.

1. Hose on the bleed port, port fully open, container under it.
2. Start a call for heat and let the burner start.
3. After the burner starts, hold the ACTION button for 15 seconds until the SYS light turns yellow, then release. The burner restarts.
4. On that start, while the igniter is still on, tap the ACTION button for one second. The control goes into pump prime and the SYS light is solid yellow for the whole four minutes. The cad cell is ignored.
5. Bleed until the oil runs clean.
6. At four minutes the SYS light goes from yellow to green and the control returns to standby. Repeat the tap on the next start if the pump is not primed yet, then end the call for heat.

Early exit is the same: end the call, or hold the ACTION button for at least one second. The 15 second hold is also the hard lockout reset on this control. A flashing yellow SYS light is a recyclerecycleWhen the control briefly shuts down after losing flame, waits, then retries on its own before deciding to lock out., not pump prime.

Carlin 60200

Sixty seconds, entered with two holds during the start of a call for heat. The lights are amber, green and red.

1. Start a call for heat.
2. During pre-ignition or valve delay on, hold the reset button until the motor stops. That takes 10 seconds. Release.
3. The motor comes back on. Within 5 seconds of that, hold the reset button again until the amber light starts to flash.
4. Release. Motor and igniter on with the amber light flashing is pump prime.

Pump prime ends when flame is detected, when 60 seconds run out, when the thermostat or limit circuit opens, or when the reset button is pressed. If you lose your place, press reset for one second and release; if the control is not in pump prime after that, start the sequence over. Releasing the first hold before 10 seconds sends the control back to standby and it starts a new call for heat. Skipping the second hold lets the normal cycle continue.

The latch-up reset on this control also starts with a 10 second hold, and then continues 20 seconds more until the lights go out. The control’s state tells them apart: latch-up shows amber and red on steady before you touch anything.

Carlin 40200 and 42230

The same two-hold sequence as the 60200, with one difference: these controls have no valve lead and no valve delay, so the first hold is during pre-ignition only.

1. Start a call for heat.
2. During pre-ignition, hold the reset button. The motor stops. Hold for the 10 seconds, then release.
3. When the motor comes back on, within 5 seconds hold the reset button until the amber light starts to flash.
4. Release. Motor and igniter on with the amber light flashing is pump prime.

Sixty seconds, and the same four exits: flame, time, thermostat or limit opening, or the reset button.

Carlin 70200

Two minutes, one hold, and a screen that says what it is doing.

1. Have a call for heat with the LIMIT icon on. No flame may be present, and the control cannot be in lockout or latch-up.
2. Hold the red reset button for 10 seconds.
3. The display reads Pump Prime. Motor, valve and igniter stay on for up to two minutes.

It ends when you press the reset button, when the two minutes run out, or five seconds after flame is sensed. If the valve is not detected, the VALVE icon flashes on entry.

Honeywell R7284

A stretched trial for ignition, one minute per press. The control has three buttons: up, down and i. The advanced version has a two line display; the basic version has one light.

1. Start a call for heat and let the burner start.
2. During the trial for ignition, press and release the up button. The display changes to PUMP PRIME with the time left.
3. Each further press of the up button adds a minute, up to 10 added minutes. Each press of the down button takes a minute off.

There is no separate exit. The added minutes are trial for ignition time, so the cad cell is still watched: if the burner lights, carry-over starts and the control goes to run; if the added time runs out with no flame, the control locks out. Holding the i button disables the burner until three seconds after it is released. On the basic version the same up press works, nothing shows it, and the limit is five minutes. Three resets without a completed call for heat put the control in restricted mode, cleared with a 10 second hold.

Honeywell R7184

Also a stretched trial. The lockout time becomes four minutes and the igniter stays on for that one cycle, then the control goes back to its labeled timings on its own.

1. Start a call for heat.
2. While the ignition is on, press and release the reset button, half a second or less. The lockout time is now four minutes (45 seconds on early units) and the igniter stays on for the cycle.
3. Bleed until the oil runs clean. If the pump is not primed within the extended time, the control locks out.
4. Repeat if needed, then end the call for heat.

Two catches. The priming cycle can only be entered if there has been no lockout since the last completed call for heat; after a lockout, hold the reset button for 30 seconds until the light flashes twice, which clears the lockout count and lets the priming press work again. And the same short press means three things on this control: priming during ignition, a cad cell resistance readout after the igniter drops out, and a lockout reset. A hold disables the burner while it is held.

Honeywell R8184G

No pump prime, purge or bleed assist of any kind. The control is a plain intermittent ignition primary with a safety switch and a reset button. Bleeding is done within the safety switch timing, 45 seconds on the G4082 and 15 seconds on the G4090, and a lockout is reset at the button. The relay check in its instructions, which jumpers the cad cell terminals, is a relay check and not a priming method.

Riello 40 series (530SE/C)

No pump prime mode. The control box runs its normal cycle and the bleed is done with the burner running. What makes Riello different is the pump: on a single line system it has no suction during pre-purge, because oil bypasses inside the pump until the solenoid valve is energized. So the pump only pulls oil once the valve opens, and a single line supply has to be gravity fed.

Single line bleed, as the service guide gives it:

1. Power off. Loosen the electrodeelectrodesThe pair of ceramic-insulated rods that arc a high-voltage spark to light the oil spray. cover about half an inch.
2. Open the oil supply valve fully and turn the bleeder fitting one full turn.
3. Start the burner. When the solenoid valve energizes, shine a light into the opening of the electrode cover and watch the oil.
4. When the pump is primed, turn the burner off, tighten the bleeder and close the cover.

Never remove the control box and jumper terminals 5 and 6 to bleed a single line system. On a single overhead line, injecting a heavier lubricating oil into the pump through the vacuumvacuumThe suction the pump pulls on the line. A technician measures it to find a clogging filter or an air leak. port first fills the gears and makes the lift easier. A two line system is self priming. If the control locks out during the bleed, the reset is the red button, and the guide’s own first check for a lockout after the trial is the oil supply: tank, valve, filter and lines.

Frequently asked questions

Does pump prime ignore the cad cell?

On the Beckett GeniSys controls, yes: the cad cell is disregarded for the whole pump prime state. On the Honeywell R7284 and R7184 the mode is a stretched trial for ignition and the cad cell is still watched, so the burner can light and go to run during the routine. The Carlin controls end pump prime when flame is detected.

Why will the R7184 not enter its priming cycle?

It refuses if there has been a lockout since the last completed call for heat. Hold the reset button for 30 seconds until the light flashes twice, which clears the lockout count, then press and release during ignition again.

How long does pump prime run?

Four minutes on the Beckett GeniSys and the Honeywell R7184, 60 seconds on the Carlin 60200, 40200 and 42230, two minutes on the Carlin 70200, and up to ten added minutes on the Honeywell R7284, five on its basic version. The R8184G and the Riello control box have no mode at all.

Is pump prime something a homeowner should use?

No. It runs the burner with the flame sensor ignored or the trial stretched, and air bled badly ends in a puff-back. The homeowner side of a run-out, and where the line to a service call sits, is on the bleeding page.

Sources

• R.W. Beckett GeniSys 7505 installation and operation manual, form 61649, pages 2, 3, 8 to 11 (read from the page images)
• R.W. Beckett GeniSys 7565 and 7585 installation and operation manual, form 62255, pages 2, 5 to 9
• Carlin 60200 data sheet MN60200H, pages 1 to 3; Carlin 40200 and 42230 data sheet MN40200E, pages 1 and 3; Carlin 70200 installation and operating instructions MN70200B, pages 1, 2, 6 and 8
• Honeywell (Resideo) R7284 installation instructions, form 69-2467, pages 1, 2, 6, 8, 9, 11 and 12
• Honeywell R7184 installation instructions, form 69-1233, pages 1 to 3, and the R7184 technician quick reference, form 69-1384, pages 1 and 2
• Honeywell (Resideo) R8184G installation instructions, form 69-0617, pages 1 to 4 (no priming function in the document)
• Riello 40 series service guide, 2024 edition, sections 4.6, 5.5.1, 5.6.1 and 5.6.2