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How to replace an oil burner nozzle in the UK

Updated: 22 October 2026

The service is booked, or you are trying to get the boiler through a cold week before the technician arrives, and the spare jet is still in its plastic case. This page explains how to replace an oil burner nozzle on a UK pressure-jet boiler: what the swap involves, the torque Danfoss publishes, and where you should stop. Peter F. used Danfoss practical guidance, OFTEC service notes, GOV.UK competent-person rules and the listings in the [oil burner nozzle comparison](/hub/heating/oil-burner-nozzle) on 20 October 2026. A qualifying purchase can earn a commission at no extra cost to you. We did not fit these jets or measure a smoke number. A nozzle change is not a full service.

The service is booked, or you are trying to get the boiler through a cold week before the technician arrives, and the spare jet is still in its plastic case.

Our top picks

Danfoss Danfoss 0.60 × 80 EH

Best overall

Danfoss Danfoss 0.60 × 80 EH
9.8/10about £12.91
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Danfoss Danfoss 0.65 × 60 ES

Rank 2

Danfoss Danfoss 0.65 × 60 ES
9.4/10about £14.00
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Danfoss Danfoss 0.65 × 80 EH

Best value

Danfoss Danfoss 0.65 × 80 EH
9.4/10about £13.00
View offer
On this page
  1. 1.Before you start
  2. 2.Removing the old nozzle safely
  3. 3.Fitting the new jet
  4. 4.After startup
  5. 5.What a full OFTEC-style service still includes

Before you start

Read flow in US gal/h, spray angle and pattern letter before you isolate anything. They must match the plate or the old stamp. If the kilogram line is unclear, use the oil burner nozzle buying guide first. Domestic tanks are usually Class C2 kerosene, and EH/ES is the family Danfoss marks to OFS E100. A diesel or waste-oil title is checked on the kerosene oil burner nozzle page. Isolate electricity and oil as the burner manual describes, and let the burner cool. Stop if the marks are unreadable, you smell oil, the burner locks out or smokes, or the job includes the fire valve, electrodes or pump pressure. Do not touch the orifice. A pin ruins the spray.

Removing the old nozzle safely

Follow the burner manual for how the head comes apart. Do not improvise past an interlock, and do not dismantle the fire valve because it is in the way. If you cannot reach the jet without forcing a guard, stop. Support the assembly so you do not twist the oil line. Keep the orifice away from fingers and tissue. Dirt in the hole is as damaging as a pin. Compare the stamp with the new packet while it is legible. If they disagree, do not fit the new jet to see what happens. Make the burner safe and reorder, or leave it for the technician.
Danfoss Danfoss 0.60 × 80 EH

Testsieger

Danfoss Danfoss 0.60 × 80 EH
9.8/10about £12.91
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Fitting the new jet

Fit the new nozzle clean, with nothing on the orifice. Danfoss publishes 15–20 Nm, and 25 Nm as the maximum. Do not copy METERXITY’s tape and a light wrench onto a Danfoss jet. Tape can shed into the orifice, and that listing gives no Newton-metre figure. Do not exceed 25 Nm because a joint wept before. If the thread will not start by hand, stop. Forcing a 9/16-24 UNEF generic into the wrong head damages the holder. Tighten once, then refit the assembly as the manual shows, including any electrode position it prints.

After startup

Start the burner only when the oil supply is back as the manual describes. If the line was opened, bleed only by the pump maker’s method. A failed ignition goes to the lockout instructions, not a series of resets. Stop if you smell oil, see smoke, or cannot clear a lockout on the first proper attempt. A flame in the sight glass is not a smoke number. Carbon dioxide, smoke and flue temperature show whether the jet is burning the right amount of oil.

What a full OFTEC-style service still includes

The nozzle is one line on a longer visit. OFTEC says service liquid-fuel appliances at least yearly, or as the manufacturer requires, and replace nozzles and flexible oil lines as required. A CD/11 report is what a registered technician produces. BS 5410 expects servicing to follow the manufacturer’s instructions. A Saturday swap does not notify Building Control.

Common questions

Can I replace the nozzle without a service visit?
You can physically change a like-for-like jet if you can isolate the burner, match the stamp and tighten to the published torque. That does not complete an annual service. OFTEC still expects combustion to be measured and a registered technician to produce a CD/11 when the service is done properly. Heat from the boiler is not that record.
What tools do I need?
The burner manual, a way to isolate electricity and oil, and a spanner arrangement that can hit 15–20 Nm without exceeding 25 Nm. You also need the correct untouched nozzle. A pin, a wire and a roll of tape are the tools that damage the orifice. If the manual calls for a nozzle spanner you do not have, wait.
What torque should I use?
Danfoss states 15–20 Nm, with a maximum of 25 Nm. Generic amazon listings that say tape and a light wrench are not a substitute for that figure. If you cannot measure torque, do not guess tightness by feel on a jet that costs less than the heat exchanger it can soot.
Do I need to bleed the pump afterwards?
Often yes if the oil line was opened, and only by the pump manufacturer’s method. This page does not give you a homemade bleed sequence. If the procedure is not in your papers, or the burner locks out when you try, a competent person should finish the start-up.
When is DIY unwise in the UK?
Stop if the burner smokes, smells of oil or locks out, if the stamp is unreadable, if the fuel is changing, or if the fire valve, pump pressure or flue is part of the fault. There is no gas-style oil landlord certificate you must produce for a nozzle alone, and there is also no sense in forcing a jet you cannot torque. Installation of an appliance or tank is a different, regulated piece of work.

Related pages

Best oil burner nozzle

Hollow or solid oil burner nozzle

Oil burner nozzle

Oil burner nozzle buying guide: flow, angle, letter

Kerosene oil burner nozzle UK: EH and ES, not diesel

Sources

Public sources named below, taken from the research digest. amazon.co.uk prices, stars and review counts on these twelve listings were taken from the listing files read on 20 October 2026. Page updated October 2026.

  1. Danfoss, Practical tips for oil nozzles (retrieved 20 October 2026)
  2. Danfoss EH/ES oil nozzles, UK design centre (retrieved 20 October 2026)
  3. City Plumbing EH/ES datasheet (retrieved 20 October 2026)
  4. OFTEC, your home guide to liquid fuel heating (retrieved 20 October 2026)
  5. OFTEC, the service (retrieved 20 October 2026)
  6. GOV.UK, competent person schemes (retrieved 20 October 2026)
  7. NHMF, oil-fired appliances (retrieved 20 October 2026)
  8. EOGB on BS 5410-1:2019 and nozzles (retrieved 20 October 2026)