Econo Heat OWB-15 Installation, Operation And Service Instructions - Water Piping Connections

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Installation, Operation, And Service Instructions

1. 

OWB-9, OWB-15, and OWB-25 boilers are shipped complete with circulating pump.  

To make the piping connections to the boiler ready to connect to the system piping, 

the following will also be required at a minimum: 

1 – Air Purger (same size as supply pipe) 

1 – Pressure reducing Fill Valve 

1 – Expansion Tank (sized to system design requirements) 

1 – Automatic Air Vent 

2. 

The following accessories may also be required, depending upon overall system 

design and code requirements: 

1 –  Low Water Cutoff  may be required if boiler is located above radiation level.  

Check requirements of state or local code bodies and insurance companies.  If 

required use a probe-type designed for water system use and install in tee in 

supply piping above the boiler. 

1 – Manual Reset High Limit----Required by some state or local codes.  Also 

required if system is to comply with ASME code. 

1 – Backflow Preventer----- Required by many State and local codes. 

3. 

Additional circulating pumps or zone valves may also be required if the system is to 

be multi-zone or if it is to include a domestic hot water storage tank with coil. 

WARNING 

The expansion tank must be properly sized to system requirements.  An under-sized 

expansion tank will cause system water to be lost through the relief valve and make-up 

water to be introduced through the fill valve.  Continual introduction of fresh water into 

the system will cause mineral build-up in the boiler sections and eventual section failure. 

4. 

There are two types of expansion tanks used, the closed type and the pre-pressurized 

diaphragm tank  Most new installations use the diaphragm type tank, however some 

installations still employ the closed type tank. 

(a)

Piping Connections with closed type expansion tank----See Figure 16.  Piping 

from tee in supply to tank should be 3/4 inch.  If horizontal piping is 

employed, pipe must be pitched up toward tank 1/4 inch per foot. 

WATER PIPING CONNECTIONS