Hydraulic valve kit instructions

Hydraulic valve kit instructions

Figure 1

Contents list

Drawing pos Quantity Size(Diameter) Description Position Causes of damage notes
105 2 19mm 3-way valve mechanism O-rings Left & right porting cone large Insufficient inhibitor
106 1 22mm Hydraulic valve-pump body union O-ring Pump body / hydraulic connection Frost and insufficient inhibitor
107 1 20mm By-pass-3-way valve union O-ring Bypass/porting block Change if required
108 2 25.3mm CH flow and return O-ring ¾” Brass flow and return connection Change if required
109 2 27mm 3-way valve external O-ring (1 already fitted to valve) Left & right-side porting block Insufficient inhibitor
110 1 17.3mm By-pass O-ring Bypass/diaphragm housing Insufficient inhibitor
112 2 17.8mm DHW in/out O-ring ½” Brass hot & cold connection Frost
117 2 6mm 3-way valve axis O-ring Left & right porting cone small Insufficient inhibitor
119 1 n/a Hydraulic valve-pump body union clip Clip pump body / hydraulic assembly Change if required
115 2 17mm Plate exchanger special joint ½” Hot and cold plate heat exchanger Frost and insufficient inhibitor
116 2 20mm Plate exchanger special joint ¾” Flow & return plate heat exchanger Frost and insufficient inhibitor
118 1 n/a 3-way valve spindle Spindle between left and right porting block Insufficient inhibitor
151 1 M5X75 Hydraulic valve screw Diaphragm housing Change if required
120 1 n/a Complete hydraulic valve n/a n/a

Advisory guidance for reassembly

  • WRAS approved silicone grease will be required
  • Ensure primary circuit is flushed and cleaned before replacing any parts
  • The primary circuit water needs to be 25% filled with Fernox Alphi 11 (combined antifreeze inhibitor mix) for minimum protection for central heating system components with a frost protection of -11 degrees centigrade
  • If the flat plates on the DHW heat exchanger have popped out the DHW heat exchanger will need to be replaced

O-ring/seal replacement instructions

  • Remove hydraulic assembly
  • Remove the 3 long screws securing the plate heat exchanger (MCB2160) to the black plastic components of the hydraulic assembly
  • Remove the clip joining the brass housing part of the complete hydraulic valve to the right of the porting block
  • Now separate the complete hydraulic valve from the porting block – Figure 2
  • Remove the clip between the flow block and the porting block – Figure 2

  • Replace the 3-way valve spindle (No.118) ensuring the brass spacer is cleaned and slid onto the 3-way valve spindle from the longest end up against the cirr clip on the 3-way valve spindle – Figure 4

  • Replace O-rings on porting cones, drawing numbers (105 x 2 and 117 x 2) – Figure 3

  • Reassemble right porting (with new O-rings) on to the new 3-way valve spindle
  • Fit O-ring (No.109) on flow block side – Figure 1

  • Fit the 3-way valve spindle with the right-hand porting slid on to the 3-way valve spindle into the right-hand side of the porting block
  • Fit the left porting onto the spindle through the left side porting block
  • Reassemble the right-hand side of the porting block to the complete hydraulic valve sliding the clip back in and ensuring the O-rings (No.109 & 110) are securely fitted
  • Fit spring and brass steering wheel shaped spring guide onto flow side of hydraulic assembly
  • Clamp together ensuring O-ring (No.109) is securely fitted. Then slide the clip home. Replace seals (Nos. 115 x 2 & 116 x 2) onto the plate heat exchanger. Now mount the hydraulic assembly onto the plate heat exchanger ensuring the seals are seated inside the main body – Figure 1 using the screws, (the right-hand screw No. 151) may need replacing if you had a very early complete hydraulic valve with a short screw
  • Now add a small amount of silicone grease to the flow restrictor and refit into the cold inlet on
  • Replace O-rings (Nos 112 x 2 & 108 x 2) onto the hydraulic inlet unions (MCB2345) attached to the base plate (MCB2420) of the boiler – Figure 1
  • Refit complete hydraulic assembly back into boiler. Please use O-ring (No. 106) & clip (No.119) for connection to the pump body – Figure 1

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