Camus Hydronics DFH/W1100, Installation, Operation And Service Manual

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Care should be taken to maintain required water velocity
based on water condition as follows:
11.8 TEMPERATURE RISE AT FULL FIRING
RATE
1 The pump must run continuously when the burner is
firing.
2 With the pump running and the burner in the water
heater or hot water supply boiler in the off cycle, the
Return/Inlet
temperature and Supply/Outlet
temperature readings on the display should read
approximately the same temperatures.
3 Turn the hot water heater on and allow time for the
temperature to stabilize. Check the temperature rise
when the burner is firing at 100% of rated input.
4 Compare the temperature rise on the display with the
required temperature rise at the required flow rate
based on water condition (Soft, Normal, and Hard).
Should adjustment be needed, proceed as follows:
If the temperature rise is too high, the water velocity is
too low. Adjust as follows:
1
Check for flow restrictions. Check for debris in strai
2 ners
3 Check diameter and equivalent length of the piping
between the storage tank and hot water heater.
4 Be sure all valves are open between the hot water
heater and the storage tank. Ensure that all ball valves
are fully ported.
5 Check the pump to be sure it is running properly and
that the pump motor is running in the proper direction.
6 Be sure the pipes between the hot water heater and
storage tank are not more than a total of 80 equivalent
feet between supply and return lines. If maximum
equivalent length for the specified pipe diameter is
exceeded, larger diameter pipe may have to be
installed to achieve correct flow and temperature rise.
7 Common manifold piping for multiple unit installations
will require larger minimum pipe sizes and tank
circulating tapping to ensure proper flow.
If the temperature rise is too low, the water velocity is
too high. Adjust as follows:
1
Temperature rise can be increased by slowly closing
the flow control valve (globe valve or flow setter) in the
outlet piping from the hot water heater to the storage
tank to achieve the proper temperature rise.
2 Sustained high water velocity and low temperature rise
may result in pitting or erosion of the copper tubes in
the heat exchangers. This is a non-warrantable failure.
Temperature rise must be properly adjusted to achieve
the specified flow rate.
The required temperature rise and the recommended pump
size are based on the heating of potable water with normal
hardness. For DHW applications with other than normal
hardness, choose a pump for the local water hardness
conditions. Alternatively, soften the water to normal levels.
Damage to the heat exchanger as a result of scaling or
corrosive water conditions in non-warrantable.
CAUTION
Temperature rise cannot be adjusted when the burner is
firing at less than 100% of input rate.
11.9 WATER HEATERS
Incorrect piping of the cold water supply to the system may
result in excessive low temperature operation causing
condensate formation on the primary heat exchanger and
operational problems. The cold water supply piping must be
installed in the discharge piping from the heater to the
storage tank. This allows the cold water to be tempered in
the storage tank before entering the heater.
The manufacturer recommends the use of a properly sized
thermostatic mixing valve to supply domestic hot water at
temperatures less than 140°F (60°C). Storing the water at a
higher temperature and thermostatically mixing the water
will decrease the size of the storage tank and increase the
available quantity of mixed hot water. Caution! Adequate
care MUST be taken to prevent potential scald injury when
storing water at 140°F (60°C) and hotter.
•
Piping components connected to the water heater for a
space heating application shall be suitable for use with
potable water.
•
Toxic chemicals, used for boiler treatment, shall not be
introduced into the potable water used for space
heating
•
A water heater which will be used to supply potable
water shall not be connected to any heating system or
component(s) previously used with a non-potable
water heating appliance
•
When a system requires water for space heating at
temperatures higher than required for other uses, a
means such as a mixing valve shall be installed to
temper the water for those uses in order to reduce
scald hazard potential.
CAUTION
Adequate care MUST be taken to prevent potential scald
injury when storing water at 140°F (60°C) and hotter.
WARNING
Should overheating occur or the gas supply fail to shut off,
do not turn off or disconnect the electrical supply to the
pump, instead, shut off the gas supply at a location
external to the appliance.