Maintenance; Maintenance Requirements; Safety Valve Operation; Strainer - Ecodan 150 Standard Installation And Servicing Instructions

MAINTENANCE

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
expansion vessel 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 Heat Pump maintenance.
After any maintenance, please complete the relevant service interval record documentation for the installation.
INSPECTION
The immersion heater boss can be used as an access for inspecting the cylinder internally.

SAFETY VALVE OPERATION

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. NOTE: Water discharged may
be very hot!
Repeat the above procedure for the expansion relief valve.

STRAINER

Turn off the cold water supply, Heat Pump and immersion heater. The lowest hot water tap should then be opened to depressurise
the system. Remove the pressure reducing cartridge to access the strainer mesh. Wash any particulate matter from the
strainer under clean water. Re-assemble ensuring the seal is correctly fitted. DO NOT use any other type of sealant.
DESCALING IMMERSION HEATER(S)
Before removing the immersion heater, the unit must be drained. Ensure the water, electrical supply and Heat Pump are OFF
before draining. Attach a hosepipe to the drain cock having sufficient length to take water to a suitable discharge point below
the level of the unit. Open a hot tap close to the unit and open the drain cock to drain the unit.
IMMERSION HEATER REMOVAL
Open the cover to the immersion heater housing and disconnect wiring from immersion heater over-temperature cut-out.
Remove the over-temperature cutout by pulling from the terminal connections on the immersion heater. Unscrew immersion
heater backnut and remove immersion heater from the unit. A key spanner is supplied with the cylinder unit for easy removal/
tightening of the backnut(s). Over time, the immersion heater gasket may become stuck to the mating surface. To break
the seal, insert a round bladed screwdriver into one of the pockets on the immersion heater and gently lever up and down.
Carefully remove any scale from the surface of the element. DO NOT use a sharp implement as damage to the element
surface could be caused. Ensure sealing surfaces are clean and seals are undamaged, if in doubt fit a new gasket.
Replace immersion heater ensuring the (right angled) element hangs vertically downwards towards the base of the unit. It
may be helpful to support the immersion heater using a round bladed screwdriver inserted into one of the thermal control
pockets whilst the backnut is tightened. Replace over-temperature cutout rod into pocket. Replace the immersion heater
over-temperature cutout by carefully plugging the two male spade terminations on the underside of the thermostat head into
the corresponding terminations on the element. Rewire, check, close and secure immersion heater housing cover.
EXPANSION VESSEL CHARGE PRESSURE
Remove the dust cap on top of the vessel. Check the charge pressure using a tyre
de-pressurised) should be 0.35MPa (3.5 bar). If it is lower than the required setting it should be re-charged using a tyre pump
(Schrader valve type). DO NOT OVER-CHARGE. Re-check the pressure and when correct replace the dust cap.
RE-COMMISSIONING
Check all electrical and plumbing connections are secure. Close the drain cock. With a hot tap open, turn on the cold water
supply and allow unit to refill. DO NOT switch on the immersion heater or Heat Pump until the unit is full. When water flows
from the hot tap, allow to flow for a short while to purge air and flush through any disturbed particles. Close hot tap and then
open successive hot taps in the system to purge any air. When completely full and purged, check system for leaks. The
heating source (immersion heater and Heat Pump) can then be switched on.
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pressure gauge. The pressure (with system