PremierPlus Unvented Hot Water Systems Maintenance and Troubleshooting

Unvented hot water systems have a continuing maintenance requirement in order to ensure safe working and optimum performance.

IMPORTANT: Maintenance of this appliance should only be carried out by a suitably qualified person.

It is essential that the relief valve(s) are periodically inspected and manually opened to ensure no blockage has occurred in the valves or discharge pipework.

Cleaning of the strainer element and replacement of the air in the expansion vessel will help to prevent possible operational faults.

IMPORTANT: Maintenance checks should be performed by a competent person on a regular basis, e.g. annually to coincide with boiler maintenance.

Standard inspection and maintenance operations are found on page 21 of the installation manual pdf.

After any maintenance, please complete the relevant Service Interval Record section of the Benchmark Checklist found on page 26 of the installation manual pdf.

Troubleshooting, Fault Finding and Heatrae Sadia Spare Parts

IMPORTANT: Servicing should only be carried out by competent persons in the installation and maintenance of unvented water heating systems

• Any spare parts used MUST be authorised parts.
• Disconnect the electrical supply before removing any electrical equipment covers.
• NEVER bypass any thermal controls or operate system without the necessary safety valves.
• Water contained in the cylinder may be very hot, especially following a thermal control failure. Caution must be taken when drawing water from the unit.

IMPORTANT: Any work carried out on the unvented water heater and its associated controls MUST be carried out by a competent installer for unvented water heating systems. In case of doubt contact service support.

Fault Finding

The fault finding chart below will enable operational faults to be identified and their possible causes rectified.

Fault	Possible Cause	Remedy
No hot water flow	Mains water supply off	Check and open stop cock
	Strainer blocked	Turn off water supply. Remove strainer and clean
	Cold water combination valve incorrectly fitted	Check and refit as required
Water from hot tap is cold	Direct immersion heater not switched on	Check and switch on
	Direct immersion heater thermal cut-out has operated	Check, reset by pushing button on thermostat
	Indirect programmer set to central heating only	Check, set to domestic hot water programme
	Indirect boiler not working	Check boiler operation. If fault is suspected consult boiler manufacturer’s instructions
	Indirect thermal cut-out has operated	Check, reset by pushing button on thermostat. Check operation of indirect thermostat
	Indirect motorised valve not connected correctly	Check wiring and/or plumbing connections to motorised valve
Water discharges from expansion valve	Intermittently. Expansion vessel charge pressure has reduced below 3.5bar, or set to high	See Maintenance section (found on page 21 of the installation manual pdf) for re-charging of expansion vessel procedure
	Continually. Cold water combination valve pressure reducer not working correctly. Expansion valve seat damaged	Check pressure from cold water combination valve. If greater than 3.5bar replace pressure reducing valve cartridge. Remove expansion valve cartridge, check condition of seat. If necessary fit new expansion valve
Water discharges from T&P relief valve	Thermal control failure CAUTION: Water will be very hot!	Switch off power to immersion heater(s) and shut down boiler. DO NOT turn off water supply. When discharge stops check all thermal controls, replace if faulty
Milky water	Oxygenated water	Water from a pressurised system releases oxygen bubbles when flowing. The milkiness will disappear after a short while

Heatrae Sadia Water Heater Spare Parts

A full range of spare parts are available for the cylinder range from UK Spares. Refer to the technical data label on the unit to identify the model installed and ensure the correct part is ordered. You will need to quote the serial number, which is printed on the data label.

PremierPlus Spares Diagram

1 Immersion heater (lower) 95606984
2 Immersion heater (upper) 95606986
3 Immersion heater gasket 70 351 65
4 Immersion heater backnut 95607869
5 Immersion heater key – not shown 95607861
6 Tundish – not shown 95605838
7 Expansion valve – 6bar 70 360 62
8 Cold water combination valve complete 70 344 68
9 Pressure reducing valve cartridge 3.5 bar 70 360 63
10 Temperature/Pressure Relief Valve 95605810
11 Expansion vessel 12 litre (100,120 and 150 litre models) – not shown 95607863
12 Expansion vessel 18 litre (170 and 210 litre models) – not shown 95607864
13 Expansion vessel 24 litre (250 and 300 litre models) – not shown 95607612
14 Blanking plate assembly – not shown 95605881
15 Nut & olive pack (4 of each) – not shown 95607838
16 Direct combined Thermostat and Thermal cut-out 95612717
17 Indirect combined Thermostst and Thermal cut-out 95612716
18 6 way terminal block 95607933
19 3 way terminal block 95607932
20 2 port motorised valve (22mm connections) – not shown 95605819
21 Terminal shroud 95 606 993
22 Control Cover 95 614 137

Download: Full PremierPlus Installation and Maintenance PDF