TemperZone TZT-100 - Water Circulation Management; Water Flow Switch Function; Circulation Pump Operation Requirements

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Heat Pump Water Heaters
MWP Series
Water Circulation
Water Flow Switch
A water ow switch is installed internally in each Thermoshell
®
.
The purpose of ow switch is to permit the product to heat only
if there is water ow through product.
The switch enables the operation of the MWP unit when
connected to any water circulation system.
The supplied TZT-100 thermostat located inside the product will
not function unless the product has power supply and the ow
switch has a closed circuit (conrming there is ow through the
product).
As there will be a minimum number of hours of operation
required to initially heat pool water and maintain pool water
temperature, the heat pump pool water circulation pump needs
to have a time clock control set/adjusted to accommodate the
minimum hours of operation required.
Initial heat-up of any pool will require a pool cover tted (ideally)
and heat pump circulation pump set to 24/7 operation until the
pool water has reached target set point and cycled off. The time
clock settings for pool water circulation pump hours-of-
operation then needs to be set to allow the product to maintain
a set pool temperature.
The run-hours to maintain pool water set point will depend upon
how the product has been sized to meet the heating
requirements, and seasonal requirements. (Refer Unit Selection
guide as part of manual to determine theoretical run hours for
pool heating).
Note: There can be unseasonal weather events that can affect
the required run-hours to maintain pool water temperature.
This may require an extension of pool water circulation pump
run-hours to compensate for the additional energy losses from
pool water, which affects pool water temperature.
Flow Switch Troubleshooting
The ow switch detects ow through product and in some rare
cases this ow switch may bounce on and off (reducing heat
output) due to air getting into system, causing inadequate ow.
Identify where air pockets could be occurring and bleed the
pipework to enable the heat pump to be able to operate as
intended. If the heat pump has operated ne previously, but ow
rate is now preventing ow switch making control circuit, carry
out a back wash and rinse of lter system and clean any
skimmer baskets in pool and pre-lters of pump to see if this
improves ow rate of circulation pump. If all fails, consult your
pool pump installer to ensure adequate ow is provided to heat
pump during heating period.
Pool water circulation via filtration system pump
In many pool heating applications the pool ltration pump is
also the circulation pump for the heat pump installed. This
pump has to run a minimum of hours per day, because of
minimum ltration requirements and incorporated chlorinating
control of pool water. If the ltration times have to be adjusted
above set hours of ltration system circulation pump, consult
the installer of chlorinating system to ensure run times does not
affect the chemical balance of pool being heated.
Pool water circulation via separate circulation pump
In some installations there are requirements for a designed
separate heating circulation pump system servicing heat pump
and pool installed. This will require an additional pump, powered
and controlled separately by others, to only activate when pool
heating set point temperature is below set point for required
pool temperature. Ensure that heat pump TZT-100 thermostat is
set at or above desired pool temperature, when using this form
of heating circulation.