Diverter valves
If you require domestic hot water and heating, 2 x 2 port diverter valves are required, you need
to supply these and they need to be 28mm diameter.
Glycol / anti-freeze
In Monobloc heat pumps the water goes outside the building. The unit can protect itself from
freezing up, but if the power goes off there is a risk that the unit will freeze causing damage.
To prevent this, we recommend putting propylene glycol mixture in the system. It is important
that the glycol concentration is adequate to protect the unit, if the unit freezes up there will be
no warranty. Manufacturer dependant, a mix of 25% is normal for UK conditions.
Adding too much glycol is not a good idea as it increases the water pump power and slightly
reduces the capacity of your system.
Heat meters
If you are using more than one heat source, heat pump + boiler you MUST measure the heat
produced by the heat pump and the electricity used. This is essential for RHI. The heat meter
goes in the return to the heat pump with a sensor in the flow. The electricity meter must
measure only the power consumed by heat pump. See hybrid drawings.
The Cylinder
If you want to heat water with a heat pump you need a dedicated heat pump cylinder.
The cylinder needs to be installed less than 15m from the control box to allow for the
temperature sensor cable. Note the size and weight of the cylinder. Full installation
instructions will be included with the cylinder.
Ideally Cylinders should only be used IF the coil area is more than 2.5m
2
. Smaller coils give very
long recovery times and increase usage of the immersion heater. Cylinders can be pressurised
or open vented. We can work out the run cost for you if you tell us the coil size.
What the Unit Comes With and What You Will
Need
