How to reset a diesel heater that has locked out

What is a lock-out?

The heater makes two attempts to light. If neither produces a flame it stops, shows a code or a flashing LED, and will not try again by itself.

• Dieselheat’s fault-finding guide says the start cycle takes about 6 minutes for the 2 attempts, after which the heater locks out. Manual
• On a digital controller that guide names the result E10. On the rotary controller Dieselheat supplies, the LED blinks evenly, about once per second, with no pauses. Manual
• The Belief manual describes the same thing as a red LED flashing slowly and continuously. Manual
• That even blink is documented for the Belief and Dieselheat rotary controller only. Vevor’s CY manual says its LED-bar dial shows an unsuccessful start as 8 flashes. Manual
• The B2010 manual defines E-10 as ignition failure after two failed ignitions, and the Hcalory M98 manual as failing to start after trying twice. Manual The Vevor XMZ manual words E-10 as a failed secondary start-up. Manual

The number is not the same everywhere. On the Hcalory HC-A01 the failed start is E-01, on the Heatport and T4 rotary-switch LCD it is E1, and other panels use other codes: check the error code tables for your controller.

How do I clear the lock-out on my heater?

It depends on whose manual you have. These are the reset statements found in the manuals read for this page.

Source	What it says
Dieselheat fault-finding guide	Remove the fuse near the battery and refit it, between start attempts and to clear an error code
Belief rotary manual	When the red LED flashes slowly, remove the fuse to reset, refit it and turn on again
Dieselheat portable guide	After running out of fuel the heater may need 1 to 2 restarts to re-prime
Heatport H2 / H4 (EnControl)	If the pump stops ticking and the screen shows OFF with E1, use fuel pumping mode or repeat the start-up

All four rows are manual statements. Manual The fuse method belongs to the Dieselheat and Belief documents. Both describe it for a heater that has finished its start attempts and stopped.

The B2010, Hcalory M98 and Vevor manuals list the failed-start code and what to check, but the notes taken from them record no reset step. Do not assume the fuse method is the maker’s instruction for those heaters.

Owner reports add little:

• One owner write-up, for a heater with a remote-style controller that showed E3 for a failed start, says switching the power off for 10 to 15 seconds clears the lock-out. Owners The write-up mixes the owner’s own steps with general advice, and the controller is not identified, so do not read it as the method for yours.
• One owner video of an Hcalory toolbox heater says that after a carbon monoxide alarm shut-down the unit has to be unplugged from power to reset. Owners That is a different shut-down, and a CO alarm is a reason to find the leak, not to reset. See safety.

If you do remove power, wait until the heater has finished its cool-down and the fan has stopped. The Heatport manual says never to cut power while the heater is running or cooling. Manual The Vevor XMZ manual says the heater needs 3 to 5 minutes to stop completely after shutdown, and the Vevor CY manual says not to cut power while the heater is hot. Manual

Why is resetting over and over a bad idea?

A failed start leaves unburnt fuel behind, and the next attempt adds to it.

• The Belief manual explains white smoke after ignition as unburnt fuel from failed starts. Manual
• The Vevor CY manual warns that over-priming causes heavy white smoke. Manual
• Two owners flooded their heaters by priming repeatedly: one re-primed 5 to 7 times and later drained fuel out of the air intake, and one found diesel all over the inside of the unit. Owners
• One owner traced an E-08 to an exhaust pipe full of unburnt fuel, which blocked the flow. Owners

Both owners got their heaters going again only after draining or cleaning the fuel out, not by resetting once more. Owners

There is one case where several cycles are expected. Dieselheat says a new heater, or one that has run dry, can need up to 6 complete start cycles to purge the fuel line, resetting with the fuse after each. Manual That applies while the line is still empty. Once fuel reaches the heater, stop repeating.

What should I check before the next start?

Dieselheat’s guide puts a failed start down to three things: no fuel, insufficient power, or no air flow. Manual Check in that order.

1. Fuel. Is there fuel in the tank, and is it moving through the line with no large bubbles while the pump ticks? Dieselheat’s test is to disconnect the fuel line at the heater and switch on: each tick should deliver about a quarter of a teaspoon of diesel. Manual Catch it in a container. If nothing arrives, the fault is upstream, and resetting will not help.
2. Power. The Belief manual wants at least 12.5 V at the heater while it starts, with the glow plug on. Manual A battery that reads healthy at rest can still sag at that moment.
3. Air. Dieselheat’s no-start checks include the air inlet and the exhaust. Manual Look at the combustion air intake and the exhaust outlet for anything blocking them.
4. Heat. If the heater ran recently, let it cool. On the Belief controller 4 flashes mean the furnace is too hot to start, and the manual says to wait 10 minutes. Manual
5. Smoke from the last attempts. If the failed starts made heavy white smoke, treat the burner as flooded and go to white smoke and no start before trying again.

If the line is empty, fill it with the controller’s priming routine and not with start attempts: see manual fuel priming. Stop priming as soon as fuel reaches the heater. Over-priming floods the burner. Some panels run a fixed priming cycle instead: the Hcalory HC-A01 knob LCD and the Vevor M-button panel count down 300 s, and the T4 and Heatport’s EnControl run a set number of pump pulses and then start the heater. The manuals give a way to stop only for the Vevor (press power), so on the others prime only a line that is really empty. Manual

When should I stop resetting and get help?

Stop if fuel is reaching the heater, the supply holds up during the start, the air paths are clear, and it still locks out. The Vevor CY and Heatport manuals list what is left, and it is inside the heater: an aged glow plug, a clogged screen next to it, or carbon in the burner. Manual The first two are covered in cleaning the glow plug and its screen. Carbon in the burner means opening the heater.

If you are not sure, ask a technician. Opening the combustion chamber goes beyond routine owner maintenance. A mistake here can cause a fuel or exhaust leak. Stop if anything is unclear.