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EHPT Accessories for UK
The procedure and recommendations specified in the cylinder unit installation manual for filling and pressurising the primary
heating circuit of the cylinder unit must be followed.
The heating return pipe and the cold water supply pipe must be provided with tees with a short length of R250 (half hard) copper
tube in the side port.
Fit the double check valve to the pipe from the mains supply pipe using the compression joint, which complies with BS EN 1252-
2, ensuring that the flow through the valve is in the same direction as the arrow on the body.
Fit the ball valve to the pipe from the heating return using the compression joint.
Connect the flexible hose between the double check valve and ball valve and tighten the wing nuts to make water tight joints.
Open both ball valves and fill the system, when the pressure starts to increase on the cylinder unit pressure gauge partially close
the ball valve on the double check valve to control the pressure to that specified by the cylinder unit installation manual.
Once filling and pressurisation have been completed, close both ball valves and remove the flexible hose.
If the flexible hose is removed it is recommended that caps (not supplied) are fitted to both valve connections to prevent any po-
tential leakage.
Maintenance and service
Pressure reducing valve
Under normal circumstances the pressure reducing valve should not require
any maintenance, but regular inspection and cleaning is recommended.
If the strainer or cartridge are damaged replace entire valve.
1. Isolate the water supply to the pressure reducing valve.
2. Unscrew anticlockwise the central calibration screw to decompress the
spring.
3. Remove the plastic cover using a spanner on the hexagon faces.
4. Extract the cartridge with the aid of long nosed pliers to grip the head of
the set screw.
5. Remove the strainer element.
*If the strainer or cartridge are damaged replace item(s) accordingly.
6. Clean the strainer element and cartridge under clean running water.
7. Replace the strainer, cartridge and cover.
8. Turn on the water supply and check for leakage.
9. Re-calibrate the pressure reducing valve. (Rotate it clockwise to
increase the outlet pressure and anticlockwise to reduce it.)
Expansion relief valve
Manually operate (rotate head anti-clockwise) the expansion relief valve to ensure free water flow through discharge port and
connecting pipe.
Expansion vessel
The pre-charge gas pressure must be checked annually to make sure that the expansion vessel is in working order.
If water discharges through the expansion relief valve, it is possible that the expansion vessel's existing gas pre-charge pressure
is too low.
Check this in the following manner:
1. Close the water supply.
2. Drain the sanitary circuit until the pressure is 0 bar.
3. Check the pre-charge.
4. Increase the gas pre-charge pressure with nitrogen/air to 3.5 bar.
Make sure that the pre-charge is not higher than the maximum working pressure.
If the expansion vessel cannot be pressurized, it is possible that the membrane has a leak.
If so, you must then replace the expansion vessel.
D-36
Optional parts
Calibration
screw
Cartridge
Strainer
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