TRIED & TESTED
78 http://www.yachtingmonthly.com APRIL 2016
Fuel-Guard
FDG1120 fuel
polishing
system
The dreaded diesel bug
can infest our fuel without
warning. Jonty Pearce
tests a way of fi ghting it
Diesel fuel quality looms increasingly large
among the problems all boat owners face.
‘Diesel bug’ microbes and their effl uent result
in sludgy deposits, ready to block our fi lters
and stop our engines at an inconvenient
moment. Biodiesel is more hygroscopic
(water-absorbing) than petroleum diesel,
so fuel producers blend it with petrol-diesel.
Currently, up to 20% of diesel in the UK
Price FGD100 Standard Filter £199
FDG1120 Water Detection System £255
FDG1120 and Polishing Kit £340
Contact Fuel-Guard
Tel 01908 230579
Web http://www.fuel-guard.co.uk
I regard this
as an essential
piece of kit.
It is well
thought-out
and engineered, needs no
replacement fi lters, and is
easy to fi t. The FDG1120 will
not only keep the diesel in
the tank clean, but also adds
another layer of fi ltration
when the engine is in use.
OUR VERDICT
PROS
■ Washable fi lter –
no ongoing costs
■ Audible, visible alarm
if water accumulates in
fi lter bowl
■ Visible fi lter through
the bowl – dirty
deposits can be seen
■ Fuel actually used
by the engine is also
fi ltered
7/
Before installing the FDG1120, I ‘dry fi tted’
it. The system is installed upstream of the
engine’s existing primary fi lter
The FDG1120
installed on
the front
bulkhead of
my engine
compartment
- the pump is
behind the
engine
I mounted
the water
detection
system
alarm by
the main
battery
switches
and Europe can be biodiesel. The problems
start once the fuel is dispensed into our fuel
tanks. For motorists and commercial users who
replenish their tanks regularly there is little
risk. For those of us who do not use a tank
of fuel every six weeks, the risk of diesel bug
infestation rises.
My 36hp Bukh engine only sips at the 260
litres of diesel in my tank; I only use half a tank
every season. The unused fuel sits over the
winter while the biodiesel attracts moisture,
allowing the bug to develop.
Add a bit of water condensation
and the bottom of the tank
provides what the fuel bug
needs for an orgy of proliferation
and fi lter blockage.
Buying fuel from a reputable
source and keeping tanks full
helps, but a fuel polishing
system is a more reliable way to stay bug free.
Fuel-Guard’s system is centred on its FDG100
fi lter, which has a 30-micron stainless steel
fi lter element and water separator. The FDG1120
has a water sensor, the polishing kit includes a
pump and a collection of fuel hose, stop valves,
T-pieces and connectors. All I needed to add
was my choice of electronic timer and a couple
of connector adaptors and hose barbs to suit
my rather ancient fi ttings.
With planning and forethought, installation
was child’s play. I connected the system via a
T-piece and stop valves to the existing primary
fi lter on the forward engine bulkhead. The
‘polishing arm’ off the T- piece was connected
by the supplied fuel hose to the pump screwed
The FDG1120
Polishing kit with
water detection
system, as supplied
by Fuel-Guard
to the side bulkhead, and this polishing
return was fed into the fuel return line via
another T-piece and stop valves.
The next step was wiring the electrical
supply for the pump, timer and water sensor.
I connected the timer and power supply to
the house ‘bypass’ fuses alongside the bilge
pump supply – this system
preserves the gas alarm and
bilge pump, when the house
battery isolator is turned off.
I’ve set the timer to turn on
for two hours a week. When
the system is running I hear a
reassuring buzz from the pump
and the splash of the returning
fuel. I do have to remember to turn off the
timer and turn the stopcocks to ‘Engine’
when I arrive on the boat – and similarly, on
leaving, the timer must be activated and the
stopcocks set to ‘Polish’.
How often the fi lter will need to be
cleaned remains to be seen – it is washable –
and any separated water can just be drained
away at the bottom of the fi lter.
CONS
■ It would be wise to
continue to use
fuel additives
■ The valve positions
need to be changed on
arriving/leaving
the boat
■ The pump is audible
when polishing fuel –
though this may
be a good point!
‘With a little
planning,
the installation
was child’s play’
PHOTOS: JONTY PEARCE