Supplied By www.heating spares.co Tel. 0161 620 6677
26
Part No. 5000893
6.17 Descaling the Heating Unit
6.16 Heating Unit - Mersey/Medway
a. Gain general access - See 6.2.
b. Drain the appliance - See 6.8.
c. Remove the 2 screws securing the
energy cut-off device to the heating unit
(located top front left).
d. Disconnect the 2 unions.
e. Remove 4 screws securing the unit to the
chassis.
f.
Carefully pull the unit from the top and lift.
DO NOT lose the 'O' rings and washers.
g. Remove the primary flue, secured by 4
screws (2 front, 2 rear).
a. Gain general access - See 6.2.
b. Drain the appliance - See 6.8.
c. Remove the heating unit - See 6.16.
Note:
On the Thames model it will be
necessary to blank off the thermostat
phial housing with a suitable plug.
d. Invert the heating unit on a suitable
bench or table.
e. Using rubber tube and acid resisting
tanks, assemble as shown in Fig.48.
f.
Fill the upper container with a proprietary
brand of descalent or a solution of 10
parts water to 1 part hydrochloric acid.
The water should preferably be hot, then
add ACID to WATER, not water to acid.
g. Adjust the pinch cock and allow the fluid
to slowly pass through the heating unit
into the collecting tank.
h. Continue the process until the fluid
ceases to bubble. It may be necessary to
replenise the solution.
i.
Disconnect and thoroughly wash out the
heating unit with clean water.
WARNING:
ACID/WATER SOLUTION
MUST BE USED WITH EXTREME
CAUTION. TAKE CARE NOT TO SPLASH
ONTO SKIN OR INTO THE EYES. WASH
ANY AFFECTED AREAS WITH LARGE
AMOUNTS OF COLD WATER AND
SEEK MEDICAL ADVICE. CARRY OUT
THE FOLLOWING OPERATION OUT OF
DOORS. ACID/WATER SOLUTION CAN
DAMAGE FURNISHINGS ETC.
Replacement Of Parts
Fig. 47
Fig. 48
