The radiators are cold, the boiler has locked out and the tank gauge reads empty. If you’ve run out of heating oil, order a delivery, then wait for the oil to settle before pressing the boiler’s reset button once. If it still won’t fire, air or sludge has probably got into the supply line and the burner needs bleeding by a technician. Give us a call on 01279 771981 and we’ll arrange a boiler repair visit across Hertfordshire and Essex.
Step one: get a delivery booked
Ring your usual supplier first. In cold spells, delivery times can stretch, so mention that you’ve run out completely. Some suppliers offer an emergency or smaller top-up delivery, but terms vary, so ask.
While you wait, switch the boiler off at the controls so it doesn’t keep trying to fire on an empty supply.
Step two: let the oil settle
A delivery stirs up the tank. Water and sediment that usually sit at the bottom get mixed through the fresh oil, and if the boiler draws that straight in, it can block the filter or the nozzle. Give the oil time to settle before you try the boiler. Your supplier or boiler manual may suggest how long.
Step three: press reset, once
Once the oil has settled, switch the boiler back on and press the reset or lockout button once. Some boilers will draw oil through and fire up normally after a minute or two.
If it locks out again, stop there. Pressing reset repeatedly can push unburnt oil into the combustion chamber, which can cause a smoky, noisy start or damage when it finally lights. That needs a technician to clear.
Why the boiler may not restart
When a tank runs dry, a few things can happen:
- Air gets into the supply line, so the pump can’t draw oil through. The line and pump need bleeding.
- Sludge from the bottom of the tank is drawn in, partly blocking the filter or nozzle.
- The pump strains trying to run without oil.
Bleeding the burner and changing filters are jobs for an OFTEC registered technician. Don’t take the burner apart yourself.
How to avoid running out again
- Check the level regularly, especially from October onwards
- Reorder at around a quarter full, rather than waiting for the gauge to drop to the bottom
- Consider a remote oil level monitor, which can show the level on your phone and alert you to sudden drops
- Keep the gauge working, as old sight gauges and float gauges can stick
- Get the tank checked at the annual service, so a leak isn’t mistaken for heavy use
A sudden, unexplained drop in level can also mean a leak or, sadly, theft. Both are worth investigating straight away.
Oil heating in rural Hertfordshire and Essex
Plenty of homes around Saffron Walden, Dunmow, Takeley and Buntingford are off the gas grid and rely on oil. Lanes in some villages can be awkward for tankers in bad weather, which is another reason to keep a buffer in the tank through winter. If your tank itself is ageing, our oil installations page explains the replacement tanks we fit.
Frequently asked questions
How long should I wait after an oil delivery before turning the boiler on?
Long enough for the disturbed sediment and water to settle back to the bottom of the tank. Suppliers and manufacturers give different guidance, so check with yours. If you’re unsure, waiting a little longer is safer than drawing dirty oil straight into the filter and burner.
Can I bleed my oil boiler myself?
Some manufacturers describe a bleeding procedure in their manuals, but it involves working on the burner and fuel pump. We’d recommend leaving it to an OFTEC registered technician, who can bleed the line, check the filter and nozzle, and make sure the boiler is firing cleanly afterwards.
Will running out of oil damage my boiler?
Not usually, if it’s dealt with properly. The main risks come from sludge being drawn into the filter and nozzle, and from repeated resets flooding the burner. A technician can clean or replace what’s needed and get it running safely again.
How much oil should I keep in the tank in winter?
There’s no fixed rule, but many households reorder at around a quarter full so a delay in delivery doesn’t leave them without heat. In a cold snap you’ll burn through oil faster, and deliveries can take longer, so it’s worth checking the level more often from autumn onwards.
Boiler won’t restart after a delivery?
If your oil boiler still won’t fire after a refill, give us a call on 01279 771981 or drop us a message and we’ll send a technician to get it running again.