PFG Series 7 Gas-fired Water Boiler — Boiler Manual

External heat exchangers

The PFG boiler can be used with a storage tank/heat exchanger unit for domestic hot water. The boiler/tank combination should be installed and wired in accordance with the tank manufacturer’s instructions, which will also show any additional components required. A zone valve or separate circulator must be installed to regulate the production of hot water.

Freeze protection

Use antifreeze especially made for hydronic systems. Inhibited propylene glycol is recommended.

Do not use automotive, ethylene glycol or undiluted antifreeze. Severe personal injury, death or substantial property damage can result.

50% solution provides protection to about -30°F

Local codes may require a back-flow preventer or actual disconnect from city water supply.

Determine quantity according to system water content. Boiler water content is listed on page 23.

Follow antifreeze manufacturer’s instructions.

Using with refrigeration system

The boiler must be installed so that chilled medium is piped in parallel with the heating boiler with appropriate valves to prevent the chilled medium from entering the boiler. Consult I=B=R Installation and Piping Guides.

If boiler is connected to heating coils located in air handling units where they can be exposed to refrigerated air, gravity circulation during the cooling cycle must be prevented with flow control valves or other automatic means.

Part Number 550-110-641/0605

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Weil-McLain PFG-7 manual External heat exchangers, Freeze protection, Using with refrigeration system