23
1. general information
6.1 Servicing instructions
To ensure effi cient safe operation, it is recommended that the
water heater is serviced annually by a competent person.
Before starting any servicing work, ensure both the gas and
electrical supplies to the water heater are isolated and the
water heater is cool.
Before and after servicing, a combustion analysis should be
made via the fl ue sampling point.
After servicing, preliminary electrical system checks must
be carried out to ensure electrical safety (i.e. polarity, earth
continuity, resistance to earth and short circuit).
A
NNUAL
M
AINTENANCE
C
HECKLIST
1.
Visually check the appliance for correct installation;
2.
Check the appliance for correct operation;
3. Check
the
fl ue and fl ue installation for correct siting,
installation and that it is in good condition;
4.
Remove the casing as described in Section 6.1.2;
5.
Check the operation of the safety devices;
- Air pressure switch
- Overheat thermostat
- Ionisation (fl ame detection)
6.
Remove and clean the water fl ow switch;
7.
Remove and clean the electrodes with an emery cloth;
8.
Remove and clean the fan;
9.
Remove and clean the burner injectors;
10. Replace all components, turn on the appliance and check
correct operation;
11. Check the gas inlet pressure and correct working
pressures (high and low fi re) as described in Section 4.4;
12. Check the gas rate;
13. Check the water fl ow rate;
14. Check the combustion CO/CO
2
as described below;
15. Advise the customer of the correct use of the appliance;
16. Complete the necessary paperwork.
C
HECKING
C
OMBUSTION
1. Check the gas inlet pressure and correct working
pressures (high and low fi re) as described in Section 4.4);
2.
Check the gas rate;
3. Check
the
fl ue and fl ue installation for correct siting,
installation and that it is in good condition;
4.
Before combustion analysis check, operate the appliance
for 10 minutes to ensure it is up to temperature;
5. Turn on the fl ue gas analyser and remove the fl ue gas
analysis test point on the fl ue accessory;
6.
Operate the appliance at maximum pressure as described
in Section 4.2. Let the fl ue gas analyser stabilise and
check the CO/CO
2
ratio;
7.
Operate the appliance at minimum pressure as described
in Section 4.2. Let the fl ue gas analyser stabilise and
check the CO/CO
2
ratio;
8.
A reading greater than 0.004 is a good indication that the
appliance combustion assembly is in need of a service
(see action points below);
