OSO 20 RD - User Manual

20 RD
20 RI
IM/5a
Installation details
The OSO unvented unit is designed for use with supply pressure up to 16 bar. For pressures over
16 bar an additional pressure reducing valve must be fitted in the supply pipe to the unit.
Wall mounting brackets are available for OSO unvented units 100-170 litres capacity.
Components supplied with the unit for site fitting
(See also page 2 for component list)
*
Multibloc valve, includes pressure reducing valve, line strainer, balanced cold water take off,
(for shower or bidet only) check and expansion valve.
*
Tundish
*
1/2''F x 15 x 15 tee piece.
*
Flexible hose.
*
3/4'' x 22mm Elbow / Drain Cock.
*
Commissioning valve, 1/2'' BSP male.
*
Motorised valve (indirect only).
Components factory fitted
*
Immersion heater(s).
*
Thermostats / thermal cut-out.
*
Temperature and pressure relief valve.
This manual gives detailed advice for installation and should be read carefully
prior to fitting any unvented unit. Where components are supplied only for
indirect units, this is clearly shown.
This OSO cylinder must be installed by a competent person and be installed in
compliance with the OSO Installation and Maintenance Instructions, all current
legislation, codes of practice and regulations governing the installation of
unvented hot water cylinders in force at the date of installation.
-1-
PLEASE LEAVE THIS MANUAL WITH THE OSO UNIT AFTER INSTALLATION
INSTALLATION MANUAL
PRODUCT REF.
HEIGHT
DIAMETER
WEIGHT EMPTY
MAX WEIGHT FULL
100
720
580
34
132
900
580
40
163
1150
580
48
215
125 170
1400
580
60
261
210
1600
580
64
303
250
2090
580
82
397
330
DIMENSION AND WEIGHTS TABLE 1
00142040-06 IM/5
Health and Safety
Manual Handling Operations Regulations 1992 defines manual
handling as: “any transporting or supporting of a load (including the
lifting, putting down, pushing, pulling, carrying or moving thereof) by
hand or bodily force”. The Regulations set no specific requirements
such as weight limits. However common sense still has to be used
based on an ergonomic approach for each individual.
20S (IM) 16pp ISSUE 8

Summary

Health and Safety Precautions

Cold Water Supply Installation

Commissioning and Draining

Safety and Maintenance Guidelines

Installation and Servicing Instructions

Cold Water Inlet Control (Multibloc)

Details on fitting the combined pressure reducing, check, and expansion valve.

Maintenance Procedures

Spare Parts Identification

Lists and part numbers for replacement components.

Tundish and Discharge Pipework Installation

Guidelines for installing the tundish and discharge pipework.

Electrical Installation

Immersion Heater Electrical Setup

Wiring and safety for immersion heaters in direct and indirect units.

Motorised Valve Installation

Installation and function of the motorised valve for indirect units.

S Plan Wiring Layout

S Plan System Schematic

Y Plan Wiring Layout

Y Plan System Schematic

OSO Fault Finding Guide

No Water Flow From Hot Taps

Troubleshooting steps for lack of hot water flow.

Water From Hot Taps Is Cold

Diagnosing and fixing issues with cold water from hot taps.

Intermittent Water Discharge

Addressing problems causing sporadic water discharge.

Continuous Water Discharge

Solutions for persistent water discharge issues.

Excessive Hot Water From Taps

Steps to diagnose and resolve excessively hot water.

Increased Volumes and High Pressure Operation

Alternative Discharge Options

Secondary Return System

OSO 20 RD Specifications

General

Volume	20 liters
Power	2000 W
Voltage	230 V
Frequency	50 Hz
Protection	IP24
Heating Element	Copper
Temperature Control	Thermostat
Safety Features	Pressure Relief Valve