Overview
The Grundfos UPS 15-20 CIL2 solar hot water 3 speed circulation pump is designed from ground up as a low energy and high efficiency solar pump suited to Australian market's open loop solar hot water systems. The Grundfos 15-20 CIL2 solar hot water pump is one of the most common oem solar hot water pump used in Australia in many pumped solar hot water systems offered by Apricus, Chromagen, Neopower, Aestiva and Therman.
This Grundfos 15-20 CIL2 solar hot water pump by All Plumbing Online is supplied with a complete AW pump kits, including pump unions, solar check valve and flow meter. The AW pump unions reduce the pump's BSP 1" thread to 1/2" with compression fittings, which can readily screw to other valves/fittings as a male thread or be connected to standard 1/2" copper pipe. The AW pump unions' loose nuts make future pump extraction easy during a service or replacement, without needing to touch other connected plumbing works.
The supplied AW flow meter comes as 1-2.5L/min gauge as standard by default. However, a 0.6-1.4L/min flow meter can be supplied by request. The flow meter uses an inbuilt ball valve to open or restrict the flow. The ideal solar hot water flow rate is in the range of 1-2L/min to promote laminar flows for better heat exchange efficiency. This slower flow rate also encourages storage tank hot water stratification by minimizing the water mixing. These data were based on my own engineering work using TRNSYS simulation when I used to calculate STC rebates for many manufacturers as consultant.
The supplied solar rated AW check valve is rated to 250 degrees. The solar check valve plays a vital role in protecting the pump and the glass of the flow meter from the back flow from the solar panels during summer stagnation, during which the flat plats can reach 180 degrees and 220 degrees for evacuated tubes. At this temperature, many other non solar rated check valves will melt and fail the protection.
The Grundfos 15-20 CIL2 pump features 3 power settings of 20W, 25W and 30W for the added flexibility. The pump is IPX4 tested for weather resistant in outdoor conditions. The Grundfos 15-20 CIL2 pump is supplied with a 500mm pre-installed electrical lead with a standard 3 pin plug for a hustle free plug-play style installation.
Due to its relatively low cost and reliability, The Grundfos 15-20 CIl2 pump is a also a popular replacement solar pump to Grundfos single speed UP15-14B PM pump used in Dux and Rinnai.
In a direct flow open loop solar hot water system in Australia, both solar panels and water tanks are pressurized by the mains supply. The pressurized water is present in the solar panels even when the pump is not pumping. Only a low power circulation pump such as Grundfos 15-20 CIL2 is required in such systems. The pump's job is only to overcome the friction and bends in the pipe work, but not to pump heads. Many customers ask if this pump can pump water from wells or swimming pools or saunas to the solar panels. The answer is no, as a more powerful pump will be required to pump heads in these applications.
Installation Notes
- A solar rated check valve MUST be installed above the pump to protect it from the solar panel's back flow. During warranty claims, the photo of the installation MUST be provided to identify this check valve or the warranty will be denied. The back flow in summer from the stagnant solar panels can reach up to 180 degrees for flat plates and 220 degrees for evacuated tubes. Without the check valve, the back flow will burn and deteriorate the internal pump seals. It will appear as a leaky pump if the water chamber seal is broken or it will appear as an electrical fault if the electrical motor side seal is compromised. All Plumbing Online recommends AW or AVG solar check valves, sold separately or as kits with this pump.
-The Grundfos 15-20 CIL2 pump propeller shaft bearings are water lubricated and must be parallel to the ground level. It is ideal to run the pump vertically, with the water flow from bottom to top. When running the pump left to right, the bearings may be at risks of being starved of water lubrication and wear out prematurely.
- For most installations up to 2 story house, speed 1 is sufficient. Spead 2 or 3 is only needed for 3 stories or extra long pipe runs. The idea is to achieve 1-2L/min flow rate with minimum power setting. During my engineering work for Apricus and many other solar hot water manufacturers, this flow rate is found to be most efficient due to the laminar flow property of the water and hot water stratification effect in the water tank. A faster flow will cause turbulence inside the panel's pipe work reducing the heat transfer. A faster flow will also stir up the water tank more, causing the colder water at the bottom to mix with the usable hot water at the top, reducing the overall hot water delivery.
- The flow meter should be fully open during the initial set up. After the water flow becomes stable, the flow meter ball valve can be closed slowly until the 1-2L/min flow rate is achieved. When the flow meter is at fully open position, the pump can usually achieve 3-4L/min flow rate range even on speed 1, which is out of the ideal efficiency range.
Technical Details
- Pump kits Manufacturer: AW
- Thread Size: Unions - BSP 1" 25mm loose nuts to 1/2" 15mm compression fittings with copper olives; Solar Check Valve: BSP 1/2" 15mm.
- SKU: G-15-20-CIL2-AW-SPK1
Package Contents
- Grundfos 15-20 CIL2 with AW unions and solar check valve kits
- Package Weight 1.8kg
Postage
Dispatch next business day. Free local pick up is available.
Warranty
2 year replacement (parts only) warranty from purchase date is offered by All Plumbing Online.
Return Policy
30 days worry free return is offered for peace of mind as per Ebay return policies. All returned items must be complete and in its original packaging.
Contact Us
All Plumbing Online is a local business based in Brisbane, run by an experienced engineer who works as a consultant to the plumbing industry at manufacturers' level. I used to operate my own plumbing company also and can answer any of your plumbing related questions, such as fitments, sizing or just chatting in general for advice. Feel free to drop me an Ebay message.