SUBMERSIBLE RAINWATER HARVESTING
Davey RainBank KRBS2 Submersible Rainwater Pump System
The Davey RainBank KRBS2 is a higher-output domestic rainwater harvesting system that combines Davey's automatic RainBank mains-water switching technology with a D53A/B submersible pump installed inside the rainwater tank.
When usable rainwater is available, the system gives the tank supply priority. If rainwater becomes unavailable, RainBank automatically allows mains water to supply the connected rainwater fixtures. Davey also designs the system to maintain mains-water availability during an electrical interruption.
Davey rates the KRBS2 configuration at approximately 63 litres per minute at 200kPa, positioning it above the smaller KRBS1 for properties requiring greater flow or pressure capability.
Installed Today can offer the KRBS2 as supply only or through eligible supplied-and-installed pathways in Brisbane and Gold Coast service areas, subject to rainwater-tank suitability, mains connection, pipework, tank access, electrical supply and the intended fixture demand.
Davey KRBS2 at a glance: RainBank automatic rainwater/mains switching, D53A/B submersible in-tank pump, approximately 63L/min at 200kPa as a KRBS2 system, higher-pressure and higher-flow Davey selection category, automatic mains backup, built-in dual-check backflow protection, 3/4-inch RainBank mains inlet and outlet connections, 1-inch rainwater inlet and a manufacturer-listed 36-month RainBank system warranty.
CURRENT MODEL
What Is the Davey RainBank KRBS2?
The KRBS2 is one of Davey's current RainBank systems designed specifically for use with a submersible pump located inside the rainwater tank.
Davey's current submersible range includes the smaller KRBS1 with a D42A/B pump and the higher-output KRBS2 with a D53A/B pump.
KRBS2
Standard submersible RainBank configuration using the D53A/B pump.
KRBS2/20
Davey also identifies a KRBS2/20 version with an extended 20-metre lead for installations requiring additional cable length.
HOW RAINBANK WORKS
How Does the KRBS2 Switch Between Rainwater and Mains?
RainBank is a dual-source water-control system. Rainwater is used as the preferred source whenever the tank and pump can supply the connected fixtures.
If tank water is unavailable, the system allows mains water to continue supplying those fixtures without the household needing to manually change valves.
The RainBank design does not re-pump mains water through the rainwater pump. Mains water passes through the controller as the backup source.
- Rainwater receives priority when available
- Automatic mains-water backup when rainwater is unavailable
- Mains-water availability during electrical interruption
- No manual source-changeover required during normal operation
- No re-pumping of mains water through the submersible pump
SYSTEM PERFORMANCE
How Much Water Can the KRBS2 Supply?
Davey rates the complete KRBS2 configuration at approximately 63L/min at 200kPa.
That operating point is more useful for comparing RainBank kits than quoting the pump's unrestricted maximum flow by itself.
Do not confuse pump maximum flow with KRBS2 system performance. The D53A/B pump alone is capable of up to approximately 130L/min under low-head conditions, while Davey's KRBS2 selection figure is 63L/min at 200kPa.
HIGHER-PRESSURE APPLICATIONS
Is the KRBS2 Suitable for Double-Storey Homes?
Davey's RainBank selection guide places the KRBS2 in its higher-pressure and higher-flow category and includes it among options for longer pipe runs and selected double-storey residential applications.
That does not mean every double-storey property automatically suits a KRBS2.
The final available pressure and flow depend on pipe size, vertical lift, pipe length, fittings, fixture demand and the number of outlets operating together.
Multiple Fixtures
The higher-output configuration provides more hydraulic capacity than the KRBS1 where several rainwater outlets may operate.
Longer Pipe Runs
The D53A/B pump provides greater head capability where the rainwater pipework extends further from the tank.
Two-Storey Applications
Davey includes KRBS2 in its higher-pressure selection guidance, with final suitability determined from the actual hydraulic layout.
D53A/B SUBMERSIBLE PUMP
What Pump Does the KRBS2 Use?
The current KRBS2 is paired with Davey's D53A/B high-pressure submersible drainage pump.
The D53A/B is designed for clean rainwater and uses a closed centrifugal impeller, corrosion-resistant stainless-steel components and automatic thermal-overload protection.
| D53A/B Pump Specification |
Manufacturer Detail |
| Maximum Pump Flow |
Approximately 130L/min |
| Maximum Total Head |
Approximately 45m |
| Maximum Submergence |
12m |
| Maximum Pumped Water Temperature |
40°C |
| Maximum Soft Solids |
Approximately 1.9mm |
| Pump Outlet |
1-inch BSP female |
| Supply |
220–240V AC, 50Hz, single phase |
| Full-Load Current |
Approximately 5.7A |
| Input Power |
Approximately 1.31kW |
| Motor Output |
Approximately 0.84kW |
| Pump Protection |
IPX8 |
| Standard Pump Lead |
Approximately 10m |
| Net Pump Weight |
Approximately 16.5kg |
SUBMERSIBLE DESIGN
Why Put the Pump Inside the Rainwater Tank?
With the KRBS2, the pressure pump operates submerged in the stored rainwater instead of sitting beside the tank.
This configuration removes the main pump motor from the above-ground area around the tank and can reduce the amount of pump noise experienced outside.
It also removes the suction-lift arrangement required by many surface pumps because the submersible pump pushes water from inside the tank.
- Pump located inside the rainwater tank
- Reduced above-ground pump footprint
- Reduced exposed pump noise
- No conventional surface-pump suction line
- Automatic pump float incorporated into the submersible arrangement
TANK WATER LEVEL
Does the KRBS2 Need a Separate Tank Float Switch?
The KRBS2 installation method uses the float system incorporated with the submersible pump.
Davey's installation instructions therefore state that there is no need to drill the tank solely to fit the separate RainBank level switch normally used with some surface-pump configurations.
The float needs enough unobstructed space within the tank to move correctly and detect the available water level.
RAINBANK CONTROLLER
What Does the RainBank Controller Do?
The RainBank unit sits outside the tank in an accessible position and manages the relationship between the rainwater pump, mains-water backup and connected rainwater fixtures.
The controller incorporates source-control components, dual-check backflow protection, operating indication and a manual-start function for commissioning or fault checks.
For a KRBS2 installation, the submersible pump remains inside the tank while the RainBank controller remains accessible for plumbing connection, inspection and servicing.
RAINBANK CONTROLLER SPECS
RainBank Operating Limits
| RainBank Specification |
Manufacturer Detail |
| Maximum Mains Flow Through Controller |
100L/min |
| Maximum Pump Flow Through Controller |
100L/min |
| Maximum Mains Pressure |
600kPa |
| Maximum Pump Pressure |
600kPa |
| Maximum Pump Current |
10A |
| Continuous Water Temperature |
Maximum 50°C |
| Minimum Water Temperature |
1°C |
| Maximum Ambient Temperature |
50°C |
| Mains Water Inlet |
3/4-inch BSP male |
| Rainwater Inlet |
1-inch BSP male |
| Outlet |
3/4-inch BSP male |
| Controller Supply |
220–250V AC, 50Hz |
| Maximum Full-Load Current |
10A |
| Controller Enclosure |
IP23 |
POWER CONNECTION
How Is the KRBS2 Powered?
The RainBank controller connects to a suitable mains power outlet, while the D53A/B pump connects to the dedicated pump socket on the RainBank controller.
This allows RainBank to control when the pump operates.
The pump should not be permanently plugged directly into the household power point during normal RainBank operation. Davey's installation instructions require the pump to connect through the RainBank controller so the system can control pump operation and prevent unnecessary continuous running.
Where a suitable electrical outlet already exists, the appliance connection is straightforward. Any new power point, circuit alteration or fixed electrical installation work needs to be separately assessed.
MAINS-WATER BACKUP
What Happens When the Rainwater Tank Is Empty?
When the available rainwater falls below the pump's operating level, RainBank allows the connected fixtures to receive water from the mains supply instead.
The system is designed so the household does not need to manually operate a changeover valve each time the tank runs dry.
When suitable rainwater becomes available again, normal rainwater-priority operation can resume.
POWER OUTAGES
What Happens During a Power Failure?
Davey designs RainBank to provide mains-water backup during electrical interruptions.
The rainwater pump cannot operate without electrical supply, so rainwater pumping stops during the outage. The RainBank source-control arrangement allows mains water to continue supplying the connected RainBank fixtures.
A power outage does not mean the submersible pump keeps operating. It means the RainBank system can maintain water to the connected fixtures by using mains-water backup instead.
BACKFLOW PROTECTION
Does RainBank Include Backflow Protection?
The RainBank controller incorporates a dual-check backflow-protection valve as part of its source-control assembly.
The completed property installation still needs to be assessed for any additional backflow requirements created by the tank type, installation layout or local plumbing conditions.
This is particularly relevant for unusual tank arrangements, below-ground installations and properties where the existing rainwater plumbing has been altered.
CLEAN RAINWATER
What Type of Water Is the D53A/B Designed to Pump?
Davey describes the D53A/B as a high-pressure drainage pump for clean rainwater and neutral-pH clean water.
The pump can tolerate only relatively small soft solids and should not be treated as a dirty-water or sludge pump.
Davey's RainBank installation guidance recommends good tank-water management, including first-flush treatment and filtration or straining where appropriate, to help stop debris entering the pump and RainBank controller.
Heavy sediment, sludge, abrasive grit and dirty tank water can shorten pump life or block system components. Tank condition should be checked before installing a replacement KRBS2.
DRINKING WATER
Does the KRBS2 Make Rainwater Safe to Drink?
No. A RainBank pump and mains-changeover controller do not treat stored rainwater or make contaminated tank water potable.
Davey's manufacturer material identifies components as suitable for contact with safe drinking water, but that is different from saying the KRBS2 purifies rainwater.
Whether rainwater can be used for drinking depends on the source, collection system, tank condition, treatment, filtration, disinfection, plumbing design and requirements applying to the property.
The KRBS2 is primarily marketed for rainwater-harvesting applications such as toilets, laundry, exterior taps and irrigation.
COMMON APPLICATIONS
What Can the KRBS2 Supply?
Toilets
Rainwater can be supplied to compatible toilet cisterns with automatic mains backup when the tank cannot supply them.
Laundry
The RainBank system can supply compatible laundry connections where the plumbing has been designed for the rainwater system.
Garden & Irrigation
The higher-output D53A/B configuration can support selected garden taps and irrigation loads where system pressure and flow are adequately sized.
TANK ACCESS
Will the D53A/B Pump Fit Through Your Tank Access?
Tank access needs to be checked before ordering a submersible pump system.
The D53A/B has an approximate overall height of 535mm and weighs approximately 16.5kg.
The tank opening must allow the pump to be safely installed and later retrieved for servicing without using the electrical lead as a lifting cable.
Davey instructs installers not to lower or retrieve the pump using its electrical lead. The installation needs an appropriate method of positioning and recovering the pump for future maintenance.
CONTROLLER LOCATION
Where Should the RainBank Controller Be Installed?
The controller should remain readily accessible outside the tank for operation, inspection and servicing.
Davey's installation information provides a wall-mounting option and requires the controller to be installed in the correct horizontal orientation.
The location also needs to remain protected from unsuitable weather exposure and close enough to the required plumbing and electrical connections.
Where RainBank components are installed inside a building, the manufacturer requires consideration of possible plumbing leakage and appropriate drainage protection.
WATER PRESSURE
What Mains-Water Pressure Can RainBank Accept?
The RainBank controller has a manufacturer-listed maximum mains-water pressure of 600kPa.
If property pressure exceeds the allowable RainBank operating limit, suitable pressure control is required before the controller.
The installer should also confirm that available mains pressure and flow are sufficient for the fixtures when the system is operating in mains-backup mode.
FILTRATION & TANK CONDITION
Should the Rainwater Be Filtered Before RainBank?
Davey's installation guidance recommends measures to reduce debris entering the rainwater system, including first-flush devices and a suitable strainer where required.
The manufacturer's plumber guidance references a 200-micron Y strainer as a useful protection measure in applicable installations.
Existing tanks containing significant sediment should be assessed before fitting a new pump because debris can affect the pump, controller and downstream valves.
SUPPLY ONLY
Buy the Davey RainBank KRBS2 Supply Only
Choose supply only where an appropriately licensed plumber or suitable rainwater-system installer is already arranged.
The product-only price does not automatically include:
- Plumbing installation
- Tank modifications
- Mains-water pipework alterations
- Additional rainwater pipework
- New isolation valves or fittings
- Pressure-control equipment
- Additional filtration
- Electrical outlet or circuit work
- Existing pump or controller removal
- Tank cleaning
- Difficult-access work
- Off-site disposal
SUPPLY & INSTALL
Davey RainBank KRBS2 Supplied & Installed
Eligible Brisbane and Gold Coast customers can select a supplied-and-installed pathway where the existing rainwater tank, mains connection and property plumbing suit the KRBS2.
Tank & Pump Check
Tank access needs to suit safe installation and future retrieval of the D53A/B pump, with enough space for its automatic float system to operate.
Hydraulic Check
Pipe size, outlet demand, vertical lift and pipe length need to suit the KRBS2's available pressure and flow.
Mains & Power Check
The RainBank controller needs a suitable mains-water backup connection and compatible electrical supply within the installation arrangement.
INSTALLATION AREAS
KRBS2 Installation in Brisbane & Gold Coast
Installed Today can provide supplied-and-installed pathways across eligible Brisbane and Gold Coast service areas where the required rainwater-system installation scope is available.
Brisbane
Gold Coast
Additional work can apply where tank access needs modification, existing pumps need removal, pipework requires rerouting, mains-water plumbing needs alteration, pressure control is required, a new electrical outlet is needed or the existing rainwater system requires repair before commissioning.
KRBS1 VS KRBS2
What Is the Difference Between KRBS1 and KRBS2?
| Specification |
KRBS1 |
KRBS2 |
| Submersible Pump |
D42A/B |
D53A/B |
| Davey Flow at 200kPa |
Approximately 40L/min |
Approximately 63L/min |
| Pump Maximum Flow |
Approximately 120L/min |
Approximately 130L/min |
| Pump Maximum Head |
Approximately 32m |
Approximately 45m |
| Higher-Pressure Selection |
Lower-output option |
Davey higher-pressure / higher-flow selection |
The KRBS1 can suit lower-demand applications, while the KRBS2 adds substantially greater pressure capability and more flow at the 200kPa comparison point.
AUTOMATIC RAINWATER WITH MAINS BACKUP
Why Choose the Davey RainBank KRBS2?
The KRBS2 combines a higher-output Davey submersible pump with automatic RainBank source control in a system designed specifically for domestic rainwater harvesting.
Its defining manufacturer figures include 63L/min at 200kPa in the KRBS2 configuration, a D53A/B pump capable of up to 45m head, automatic rainwater priority, automatic mains backup and built-in dual-check backflow protection.
It is particularly relevant where a property needs more pressure or flow than Davey's smaller submersible RainBank option and where placing the pump inside the rainwater tank is preferable to using an external surface pump.
WARRANTY
Davey RainBank KRBS2 Warranty
Davey's current RainBank with Submersible Pumps product listing states a 36-month manufacturer warranty period.
Warranty remains subject to Davey's applicable conditions, correct product selection, suitable water quality, correct installation and operation within the manufacturer's limits.
Standalone component warranty periods shown elsewhere in Davey's pump range can differ from the warranty shown for the complete RainBank submersible-system product.
COMMON QUESTIONS
Questions About the Davey RainBank KRBS2
Is the KRBS2 Still a Current Davey Product?
Yes. Davey currently lists KRBS2 within its RainBank with Submersible Pumps range.
What Pump Does the KRBS2 Use?
The KRBS2 is paired with Davey's D53A/B submersible high-pressure pump.
How Much Flow Does the KRBS2 Provide?
Davey lists approximately 63L/min at 200kPa for the KRBS2 configuration.
What Is the Maximum Flow of the D53A/B Pump Itself?
The standalone D53A/B pump is rated to approximately 130L/min. This is not the same as its 63L/min KRBS2 operating point at 200kPa.
What Is the Maximum Pump Head?
The D53A/B has a manufacturer-listed maximum total head of approximately 45 metres.
Is the Pump Inside the Tank?
Yes. The KRBS2 is Davey's submersible RainBank configuration, with the D53A/B installed inside the rainwater tank.
Does It Need a Separate Tank Float Switch?
The KRBS2 installation uses the float control associated with the submersible pump, so Davey's installation pathway does not require the separate RainBank tank float used on some surface-pump arrangements.
Does RainBank Use Rainwater First?
Yes. Rainwater is the preferred water source whenever a suitable rainwater supply is available.
What Happens When the Tank Runs Empty?
RainBank automatically allows mains water to supply the connected fixtures.
What Happens During a Power Outage?
The submersible pump stops because it has no electrical power, while RainBank's mains-backup arrangement allows mains water to remain available to the connected fixtures.
Does It Have Built-In Backflow Protection?
Yes. Davey identifies a built-in dual-check valve within the RainBank system. The complete installation may still require additional backflow provisions depending on the property and tank arrangement.
Can It Supply Toilets?
Yes. Toilets are one of Davey's core RainBank applications.
Can It Supply the Laundry?
Yes. Davey also markets RainBank for compatible laundry rainwater applications.
Can It Be Used for Garden Irrigation?
Yes, where the irrigation flow and pressure requirements fall within the capability of the KRBS2 and the property's pipework.
Is It Suitable for a Double-Storey House?
Davey places KRBS2 in its higher-pressure selection category and includes it in guidance for longer pipe runs and selected double-storey applications. Final suitability depends on the hydraulic layout and required outlet flow.
What Is the Maximum Mains Pressure Through RainBank?
The RainBank controller operating limit is 600kPa.
What Size Is the Mains Connection?
The RainBank mains-water inlet is 3/4-inch BSP male.
What Size Is the Rainwater Connection?
The RainBank rainwater inlet is 1-inch BSP male.
What Size Is the RainBank Outlet?
The outlet is 3/4-inch BSP male.
What Electrical Supply Does the Pump Use?
The D53A/B uses 220–240V AC, 50Hz single-phase power and has a manufacturer-listed full-load current of approximately 5.7A.
Where Does the Pump Plug In?
The pump connects to the pump socket on the RainBank controller, and the RainBank controller connects to the property's suitable power outlet.
How Deep Can the D53A/B Be Submerged?
Davey lists a maximum submergence of approximately 12 metres.
Is the KRBS2 for Dirty Water?
No. The D53A/B is intended for clean rainwater or similar clean neutral-pH water and should not be treated as a sludge or dirty-water pump.
Does the KRBS2 Make Rainwater Drinkable?
No. The pump and RainBank controller move and manage water sources; they do not purify the tank water.
What Is the KRBS2/20?
Davey identifies KRBS2/20 as the extended-lead version of the KRBS2, with a 20-metre lead for suitable installations.
What Is the Warranty?
Davey's current RainBank with Submersible Pumps product page lists a 36-month warranty, subject to manufacturer terms.
Can I Buy the KRBS2 Supply Only?
Yes. Supply only suits customers who already have a suitable licensed installer arranged.
Can Installed Today Install the KRBS2?
Eligible Brisbane and Gold Coast properties can select a supplied-and-installed pathway where the tank, plumbing, mains backup, electrical supply, fixture demand and access are suitable.
FINAL CHECK
Is the Davey RainBank KRBS2 Right for Your Property?
The Davey KRBS2 is primarily aimed at domestic rainwater systems needing automatic mains backup together with more pressure and flow capability than Davey's smaller submersible RainBank configuration.
Current manufacturer information pairs it with the D53A/B submersible pump and lists approximately 63L/min at 200kPa for the KRBS2 system, while the pump itself provides up to approximately 45m maximum head.
Before ordering, check the tank access opening, tank cleanliness, pump location, float clearance, pipe lengths and sizes, intended outlets, vertical lift, mains-water pressure, controller location and electrical supply.
For supply only, arrange an appropriately licensed installer. For eligible Brisbane and Gold Coast properties, select the matching supplied-and-installed pathway and any required plumbing, pressure-control, filtration, electrical, removal or access add-ons before checkout.
