We use the Grundfos Solar 15-65 B for closed loop and open loop solar hot water systems. Plumbing repairs on the saxon system can be tricky but we have
had plenty of experience in fixing these systems over the last 8 to 9 years.
The Grundfos 15-5B circulating pump was bought into the country and used with the Saxon closed loop Solar Power SP4002 solar hot water system. It has a
higher head capacity then the Grundfos Solar 15-20 CIL. The Grundfos 15-20 CIL is not a suitable replacement pump for the Viking pump used in the Solar
Power SP4002 hot water system.
Saxon solar hot water systems are no longer made. However, we have managed to secure a quantity of the Grundfos
Solar 15-65 B circulating pumps as replacement parts. This pump can be used with similar solar hot water systems made by Solar Power and Solar
Land that made use of the Saxon tank.
Solar Hot Water Repairs QLD repair solar hot water systems on the Sunshine Coast but also from Brisbane to Hervey Bay. For all solar hot water enquiries please call 0455 265 539 or email firstname.lastname@example.org.
The Grundfos Solar 15 65 B solar hot water circulating pump is an OEM pump that has been supplied to replace the viking solar hot water pump in the
Saxon SP4002 Solar Power solar hot water system.
The viking pump is no longer made. See below information on the controller used with the original pump.
The controller measures the temperature of a roof mounted collector and the temperature of a water storage tank. When the tank temperature is low and the
collector is hot, the controller will turn on the pump to recirculate water from the tank through the collector. Water passing through the collector
will be heated from the sun.
If the water in the tank is already hot, then the pump will not run regardless of how sunny and lovely the day is.
This system is not a pure solar system. It is a boost system that aims to reduce but not eliminate gas or electricity use. It is most cost effective with
paired with an off-peak electric system, where solar will be the only source of heat during the day and electricity will be used at night.
Temperature Sensor Inputs
The controller requires either 2 or 3 temperature sensors, depending upon the type of tank.
Most installations will use 2 temperature sensors. One sensor will be placed in the water tank and be connected to the Tank Bottom input. The other sensor will be placed up at the collector and be connected to the Solar Collector input.
The 85°C/75°C link should be REMOVED for the 2 sensor system.
In the 2 sensor system, the pump will only operate if the collector is hot and the tank temperature is below 82°C. It will turn the pump off when
the tank temperature reaches 85°C.
Other installations that have a lower temperature water tank use 3 temperature sensors. Two sensors are placed in the water tank, one near the
bottom the other near the top. This is to ensure no part of the tank ever gets too hot. They are connected to the Tank Bottom and Tank Top inputs. The third sensor will be placed up at the collector and be connected to the Solar Collector input.
The 85°C/75°C link should be INSTALLED for the 3 sensor system. Do not remove the link as the tank may be damaged and is costly
In the 3 sensor system, the pump will only operate if the collector is hot and the tank temperature is below 71°C. It will turn the pump off when
the tank temperature reaches 74°C. Only the bottom sensor is used to determine if the pump should turn on, but it will turn off when either
sensors detects it's too hot.
The three sensor system also supports frost prevention. If the collector temperature falls below the defrost threshold, the pump will turn on to
pump hot water from the tank through the collector coils to protect them from the effects of the water freezing in the tubing. Pumping will
continue for at least 15 minutes, unless a sensor fault is detected.
The indicator LED may help diagnose faults. It indicates the following things: