What to consider when choosing a solar hot water circulating pump based on the pumps head:
The head rating on a pump is a static rating, and applies to the maximum head in an open loop system, such as pumping up to a roof tank. In the case of circulation through a roof panel and back down a return line, once the system is primed the weight of water falling down the return line is equal to the weight of water in the feed line, and essentially the pump only needs to overcome the total pipe friction in the system. When you take this into account the limitation is more to do with pipe length than the height.
When replacing the pump, it is also a good idea to replace the non return valve with an AVG solar rated non return valve . Most manufacturers require the non return valve to protect the circulating pump for several reasons. If you have time, take a look at the Grundfos 15-20 CIL 2 in our complete pump stations . The pump station housing has been designed to give the Grundfos 15-20 CIL 2 the best possible protection. They come complete with your choice of the RESOL DeltaSol BS/4 or Senztek SolaStat digital controllers and include a full set of sensors and valves.
The Grundfos 15-20 CIL 2 circulating pump can be used as a replacement pump* for all open loop solar systems, both flat plate & evacuated solar hot water systems. The Grundfos 15-20 CIL 2 is from the Grundfos solar range and has been made to last. Below we have listed the major manufacturers to assist with your circulating pump selection.
Flat Plate Solar Hot Water Systems
- Hills Solar
- Bradford Solar
Evacuated Tube Solar Hot Water Systems
- Neo Power
- Hills Solar
- Heavenly Solar
- Endless Solar
- Bambo Direct
The Grundfos 15-20 CIL 2 circulating pump will work with most brands of solar hot water systems. Please check with us if you are not sure.
* some pipework modification might be required
Grundfos 15 20 cil pump orientation Pump orientation may differ depending on installation. Circulating pumps are not designed to be installed externally. However, if installed externally, the Grundfos 15 20 Cil will need to be installed into a weather proof housing. The Grundfos 15 20 Cil comes assembled ready to install into the protective pump station cover, below. If the pump is not being installed into this style of pump station housing, the orientation of the motor will need to be changed. This can easily be changed once installed by undoing the four allen key bolts connecting the pump to the housing, rotating the pump motor so the lead is facing towards the ground with the variable speed switch to the side and not facing up. Make sure the direction of flow is flowing the correct way. Circulating pumps should be installed correctly with the flow flowing vertically and are not to be installed in the horizontal position as this position can cause damage to the pump and is an incorrect installation of the pump. Circulating pumps need to be installed by a licensed plumber. Incorrect installation may void any warranty.