Maintenance - andrews MAXXflo CWH30/200 Installation Manual, Operation And Maintenance Manual

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SECTION XX • XXXXXXXXX SECTION 7 • MAINTENANCE

MAINTENANCE

At least once a year, the following works must be
carried out:
1. Check the CO percentage and adjust if necessary,
2
(see page 33).
2. Check the output at full load by measuring the gas
usage. If this deviates more than 15% from the
nominal value (see Section 2, Technical Details) then
this is an indication of dirt or blockages in the flue gas
extraction channel, the air supply channel or the
condensation extractor.
3. Switch off the electricity supply. Check the
condensation extraction and rinse the condensation
tray and condensation extraction with clean pipe
water. An opening has been provided for this on the
top of the condensation tray, see Fig 16. When no
more impurities come out then the condensation
extraction is clean.
4. Check the ionisation electrode. This must be straight
and clean (light residue is normal).
Fig 16 – Flushing Point
5. Flush the water heater tank by opening the drainage
tap. Let water flow out of the water heater until no
more chalk residue comes out with the water. In areas
with hard water, it is necessary to flush out the water
heater more frequently.
6. If the water heater is to be drained for any reason, first
take the water heater out of operation and then
proceed as follows:
a. Turn off the water tap in the cold water supply
b. Open one of the warm water taps that can be
found at a point higher that the water heater in order to
bleed the warm water pipe section. If the water heater
is set up above the level of the drainage points, it will
be necessary to open the warm water connection to
let the appliance run empty.
c. Open the drainage tap of the water heater so the
appliance runs empty. Be careful, the water flowing out
can be very hot!
7. The storage tank should be inspected annually and
cleaned if required. To gain access, first drain the tank
as above. Disconnect any pipework connections to
allow removal of the tank cover, including the pipes
from the T&P valve (the valves should be left in position
in the inspection cover), remove sixteen M10 bolts and
washers securing the cover at the top. Lift off the
cover, retain the O ring seal for refitting; alternatively, a
new seal may be required. When refitting the cover,
locate the O ring in the groove and fasten cover using
the bolts and washers. Do not over-tighten; the torque
setting should be 60Nm.
Burner and exchanger
The burner and exchanger do not normally need to be
cleaned. If there is a suspicion of dirt then the exchanger
should be opened on the bottom. New gaskets must
always be used when assembling. The top of the
exchanger must never be opened.
The hot surface igniter is a vulnerable part that should
only be removed if it has to be replaced.
Only original parts recommended by the manufacturer
can be used as replacement parts. Components that are
sealed may not be changed or dismantled.