Operation instructions

3.10 Recirculation application

Since recirculation through the heater is not permissible, the following drawing is provided to outline a proper recirculation application using the BOSCH PRO water heater with an Ariston minitank. This schematic is for illustration only and must not be used for actual installation without appropriate engineering and technical advice from a professional properly licensed in locality where the installation is made.

4Operation instructions

4.1For your safety read before operating your water heater

Warning: If you do not follow these instructions exactly, a fire or explosion may result causing property damage, personal injury or loss of life.

Fig. 17 Recirculation application

The use of a small electric mini-tank (4-6 gallon size) should be used for this application and designed so the pump will circulate the water through the mini-tank and the building's hot water return loop only. A timed or thermostatically controlled operation of the pump is commonly done. The GWH 425 PN should be plumbed in line before the mini-tank water heater. Contact Bosch Water Heating if further instruction is needed.

Note: Upon initial installation,

iexistence of air in the gas supply line and in the water line may cause some ignition delay. In that case, repeat the ignition process until all the air has been purged.

A.This appliance employs a piezo-igniter to light the pilot burner. When lighting the pilot, follow these instructions exactly.

B.What to do if you smell gas.

WHAT TO DO IF YOU SMELL GAS

BClose gas valve. Open windows.

BDo not try to light any appliance.

BDo not touch any electric switch; do not use any phone in your building.

BImmediately call your gas supplier from a neighbors phone. Follow the gas supplier’s instructions.

BIf you cannot reach your gas supplier, call the fire department.

C. Use only your hand to push in the gas control buttons. Never use tools. If a button will not push in, check to make sure the buttons are being pushed in the proper sequence. Follow these instructions exactly. If control button(s) are jammed, close the heater’s individual manual shutoff valve and call a qualified service technician. Forced or attempted repair may result in a fire or explosion.

D. Do not use this appliance if any part has been under water. Immediately call a qualified service technician to inspect the appliance and to replace any part of the control system and any gas control which has been under water.

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