Heatrae Sadia Megaflo Eco 125DD, Manual

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9. Maintenance
9.1 General
Maintenance requirements
Unvented hot water systems have a continuing
maintenance requirement in order to ensure safe
working and optimum performance. 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.
Similarly cleaning of the strainer element and
replacement of the air in the internal expansion volume
will help to prevent possible operational faults.
The maintenance checks described below should be
performed by a competent person on a regular basis,
e.g. annually to coincide with boiler maintenance.
After any maintenance, please complete the relevant
Service Interval Record section of the Benchmark
Checklist on page 35 of this document.
9.2 Standard inspection & maintenance
operations
Inspection
The immersion heater boss can be used as an access
for inspecting the cylinder internally.
Safety valve operation
CAUTION
Water discharged may be very hot!
`
Manually operate the temperature/pressure relief
valve for a few seconds.
`
Check water is discharged and that it flows freely
through the tundish and discharge pipework.
`
Check valve reseats correctly when released.
`
Repeat the above procedure for the expansion
relief valve.
Strainer
`
Turn off the isolating valve prior to the Pressure
Reducing Valve or the main stop cock to the
system.
`
Open the lowest hot tap in the system to relieve the
system pressure.
`
Using a spanner unscrew the pressure reducing
cartridge and remove the moulded housing. The
strainer will be removed with the cartridge.
`
Wash any particulate matter from the strainer
under clean running water.
`
Replace the strainer and screw the Pressure
Reducing Valve cartridge into the moulded housing.
`
Close hot tap, turn on isolating valve or main stop
cock to the system. Check for leaks.