Dru G20, Installation Manual

English

I NS TAL LAT ION M ANUA L

2.12 Does appliance switch off
exactly 22 sec after
servomotor starts running?

2.19 Replace gas control
(thermo-electric valve does not
shut down quick enough because
of some permanent magnetism)

2.14 Does main burner go out
after 'some time'?

2.18 Can fire be switched off?

2.20 Perfect!
You have a well functioning
fire

2.16 Is flame picture OK?

2.13 Check cross lighting main
burner and 2nd thermocouple
system.

Measure voltage of 2nd
thermocouple
-

Check voltage in mV, 22 sec
after servomotor starts to run,
c.q. just before fire goes out.
Glass window to be mounted!

-

Measure between black wire +
earth point on gas control.

-

Requirement: voltage >5 mV
after rectification actions.

Voltage 0 mV
-

2nd couple defective.

-

Cross ligting main burner very
slow. Take actions "Cross
lighting too slow" (see below),
before taking any further
action!!

Voltage <1,8 mV
-

Cross ligting main burner too
slow. Take actions "Cross
lighting too slow" (see below),
before taking any further action!

-

2nd couple barred. Check:
- 2nd couple free of vermiculite,
chips or pebbles;
- position of logs or pebbles;
- burner holes under 2nd couple
open.

-

2nd couple defective (cross
lighting OK, but voltage creeps
up too slow).

-

Flames instable, see 2.15.
Rectify, before any other action
is taken!!

-

Burner pressure (too high or too
low).

-

2nd couple not positioned
correctly in flame.
Bend into correct position (see
manual).

-

2nd thermocouple positioned
correctly (see manual). Bend
into flame (only if cross lighting
and flame picture are OK!! See
2.17).

Voltage > 1,8 mV
-

Receiver defective. Replace.

Cross lighting of main burner too
slow
Measure the time in sec from start
running of servomotor till the flame
reaches the 2nd couple.
Requirement: the flame must be in
position at the 2nd couple <10 sec.
If not, check:
-

2nd couple free from
vermiculite, chips or pebbles;

-

position of logs or pebbles;

-

burner holes (locally) blocked.
Remove vermiculite dust.

-

vermiculite missing or not
evenly distributed across
burner(s);

-

chips on burner;

-

lack of combustion air. See 2.15.

-

cross lighting in low setting
(possible when thermostat
function is used).

2.15 Check
Gas supply
-

Supply pressure does not
drop away as main burner (or
other appliance) lights,
causing pilot flame to shorten.

-

Burner pressure (too high or
too low).

Flames instable (suffocating, lack
of air).
Dancing flames on burner.
Lack of combustion air. Check:
-

flue system permissible;

-

proper flue terminal used,
make should be 'DRU';

-

terminal correctly sited on
roof or wall relative to
obstructions;

-

integrity of flueing system (no
interruptions, not barred,
cobwebs);

-

air inlet guides;

-

flue restrictor/damper;

-

throttle rings.
See manual for specific
requirements.

PowerVent®
Possibly not enough draught. Check
if pressure difference set too high.
Consult PowerVent® installation
manual.

Pilot burner
-

Pilot burner dirty. Weak pilot
flame being drawn away by
flames main burner.
Clean with compressed air.
See 2.04.

2.17 Check
Flames: too low
-

Supply pressure does not
drop away as main burner or
other appliances in the
building light, causing flames
to shorten.

-

Burner pressure (too low).

-

False air: Check soundness
glass window gasket/
soundness of the connection
of the glass panes of
two/three sided appliances
(no slots allowed).

Flames: too high
-

Line pressure.

-

Burner pressure.
Flames: no even distribution
or
out on part of the burner(s)

-

Position of logs or pebbles.

-

Burner holes (locally) blocked.
Remove vermiculite dust.

-

Vermiculite not distributed
evenly across burner(s).

-

Adjustment of throttle ring(s).

Flames: too blue/too yellow or
sooting
-

Air inlet guides.

-

Flue restrictor/damper.

-

Adjustment of throttle ring(s).

Flames: suffocating: lack of air
You see dancing flames on burner,
seeking for air. See 2.15.

Flame picture 'restless'
Indication of too much draught.
Check:
-

adjustment of appliance
damper and air inlet guides);
vertical flue length allowed
(<12 m);

-

window glass not mounted
gas tight.

PowerVent®? Check:
Possibly too much draught. Check:
-

Pressure difference set too
high.

-

Silicon pressure measurement
hoses leaking.

Consult PowerVent® installation
manual for more info.

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UK