Location Of Controls - Raypak B0507 Owner's Manual And Installation Instructions

ELECTRONIC THERMOSTAT
On/Off Models
On/Off type water heaters are fitted with an Eliwell IC902 electronic thermostat that has a temperature sensor
located in the inlet side of the water heater header. This type of thermostat is used where the system load is
constant (e.g. hot water supplied from a storage tank or in floor slab heating).
NOTE: If the water heater is connected to a storage tank with a tank thermostat fitted, the water heaters electronic
thermostat set point should be set 5º higher than the tank thermostat setting.
Modulating Models
Water heaters with modulating operation are fitted with an RWF55 adjustable electronic thermostat that has a
temperature sensor located in the outlet side of the water heater header. This type of thermostat is used where the
system load is variable e.g. Mechanical Heating. The electronic thermostat will cycle the burner from full fire to 30%
and then off.
GAS CONTROL
On/Off Models Natural Gas 507-992 & Propane 507-1922
On/Off type water heaters models 507-992 (natural gas) and models 507 - 1922 (propane gas) are fitted with a
Brahma GVC30 double block gas valve.
On/Off Models Natural Gas 1142-4224 and Propane 2004-4224
On/Off type water heaters models 1142-4224 (natural gas) and 2004-4224 (propane gas) are fitted with a Siemens
VGD series double block gas valve and Siemens SKP15 and SKP25 (SKP25.003) actuators.
Modulating Models
Modulating type water heaters are fitted with a Siemens VGD series double block gas valve that has Siemens
SKP15 and SKP25 (SKP25.703) actuators. Modulation is done via a Siemens SQS37 modulating motor. The
RWF55 electronic thermostat controls the modulating motor so that the gas rate modulates to match the required
heating load. Modulating water heaters are usually installed on a heating system with radiators or a fan coil.
HIGH LIMIT THERMOSTAT
The high limit thermostat is a manual reset over temperature thermostat that will
automatically switch off and shut down the water heater in the event of a temperature
control or water flow fault. When the system water temperature has cooled sufficiently,
the high limit thermostat can be manually reset as follows:
1. Using a flat bladed screwdriver, unscrew and remove high limit reset lever cap
located on front of high limit.
2. Use the screwdriver to lift the high limit reset lever to the up position as depicted
in the illustration shown opposite.
3. Replace high limit reset lever screw cap.
FLOW SWITCH
A flow switch is provided with the
water heater and is wired to prevent
operation of the main burner in the
event of no water flow.
RATING LABEL
The rating label details the model
number, serial number, gas type,
burner pressure, water pressure and
electrical specifications of the water
heater. The rating label is located
behind the access panel on the inside
left hand side of the water heater.

LOCATION OF CONTROLS

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