Oil boilers are considered to be rather outdated now, what with the UK Government pledging* to have us all driving around in electric cars and heating our homes with hydrogen. While not saying where the electricity, or the hydrogen, will be coming from, of course.

*Sensibly, these promises are being made with a timescale of at least 15 years away, meaning they are worthless.

Amidst these pontifications, a boiler manufacturer has quietly beavered away and come up with a very low Nox (Nitrous Oxide) oil boiler; in fact, it is billed as the least polluting oil boiler you can install today.

As an installation company that likes to offer the very best products, to our appreciative and discerning customers, we had to be involved.

All hail the Navien LCB 700 oil boiler. This boiler burns with a blue flame, reducing soot and particulates.

Navien LCB700 external system boiler

Other manufacturers in the UK have brought out ‘blue flame’ oil boilers in the last 24 months, but these have involved buying a oil burner from an Italian or German company, and coupling it to an existing boiler design.

Navian have completely redesigned the oil boiler, from the ground up. This boiler weighs less than 70Kg because it is solely made from stainless steel. Most, if not all UK oil boilers are made primarily from mild steel. It has a modulating oil pump, and a separate modulating air fan, the likes of which oil technicians in the UK have never seen before.

Variable speed air fan in foreground, 2 stage motor driven oil pump to the left

So it may surprise you to know that the Navien LCB700 is the World’s best selling oil boiler. We were one of the last markets to see it.

Grundfos system pump

It is found across Asia, Russia, and the USA* (*where the best selling gas boiler is also …..Navien).

The Navien LCB comes in different formats, heat only, system and combination.

The combination boiler incorporates all the clever aspects of their normal boilers, but adds hot water temperature and flow regulation accurate down to 1C variance at the tap; does your oil combi do that?

Nearly finished

The flue system can easily extend 20 metres, so siting the unit is far more flexible.

And the exhaust doesn’t smell of oil, because the combustion is so accurate. I could rave on about the air fan running on after the oil has stopped, the pump overrun, the 100mm diameter plastic flue shared with gas boilers, the clever diagnostics and inbuilt compensation, but I don’t want to appear an anorak.

Control interface and diagnostics

Our customer today lives in a terraced property in a small village on the outskirts of Leatherhead, Surrey.

Free parking, too

Her HRM Wallstar boiler had become unreliable and her trusted boiler man had been back countless times to repair it, but she still had to get up most mornings and reset it.

Maligned HRM Wallstar being used for Powerflush; powerflushing chemicals work better in warm water. Note photocell being left out of the boiler to make it stay on…

She selected Hot Water & Central Heating Ltd, because other local customers had recommended us.

Wallstar internal view

We suggested the new Navien LCB700 because it represented a new era for kerosene boilers in the UK, a track record across the World, and a 10 year warranty.

This boiler was last serviced a few months ago. Apparently the technician thought it needed more mastic inside to keep it working…. the truth was further inside

When we dismantled the outgoing HRM Wallstar, it became obvious that a baffle inside had fallen in front of the burner at some point. Someone had taken the burner out and put the badly damaged baffle back in the correct position; incredibly, not choosing to renew it!

Bottom left hand of burner baffle has seen some trauma. It was in the correct location when we dismantled the boiler – so clearly someone had moved it, this was the cause of the nuisance lockouts.

As a result the photocell wasn’t allowing the boiler to run in daylight. We used the old unit reliably all day to run our Powerflush and Magnacleanse system, by operating the photocell with a gloved hand.

We constructed a plinth from slabs (to level the site and protect the boiler from flooding) and installed the new boiler – in the most inhospitable external conditions, driving rain, high winds, and even sleet at one point.

Flooding protection plinth. NB: Louvred box to the left is an AGA cooker vent.

Fortunately, our customer was determined to look after us throughout with endless coffees and bacon sandwiches, choccy biscuits and crumpets. A better welcome we could not have received.

The Navien external unit comes in a highly insulated attractive green casing.

Casing is properly insulated

When it gets very cold overnight, it intelligently runs the pump to keep itself warm from water in the house radiators in preference to wasting oil.

There are major differences on this South Korean unit to what we are used to in the UK. The installation process isn’t quite the same, but in my view this is progress and every day is an opportunity to learn.

MagnaClean 2 fitted inside the room

We’d like to thank Navien UK and our customer for their support.

Wall hung Navien gas boilers can also be installed externally, freeing up space; so we hope to be updating this blog soon with a case study on an external gas combi boiler.

If we can modernise your heating system whilst making emissions and fuel consumption as low as feasible, please get in touch.