♨️ Laing / Goulds E5 SilentFlo Circulation Pump – 3/4″ Smooth Barb
Ultra-compact, whisper-quiet circulation for continuous spa operation
💧 Product Overview
The Laing E5 Fixed Speed Pump is a compact circulation pump designed for continuous operation in spas and hot tubs, providing efficient water flow with exceptionally low energy consumption. Drawing just 0.2A and consuming only 0.039 kW (39W), this ultra-efficient pump is engineered for economical 24/7 operation whilst keeping running costs to an absolute minimum.
With an ultra-compact body measuring just 135mm × 90mm × 115mm, the E5 is one of the smallest circulation pumps available, making it ideal for installations where space is at a premium. The ¾-inch smooth barb connections provide easy integration with standard spa plumbing using flexible vinyl hose.
The E5 is specifically designed as a direct replacement for the Watkins SilentFlo® 5000 and SilentFlo 5002 circulation pumps (part numbers 74428 and 74427), making it the perfect choice for Hot Spring, Tiger River, and other Watkins-manufactured spas. The pump is supplied without a power cord, allowing you to reuse your existing 3-core cable from the old pump.
✨ Key Features
✅ Ultra-Low Power Consumption – Just 0.039 kW (39W) / 0.2A for minimal running costs
✅ Ultra-Compact Design – Tiny 135mm × 90mm × 115mm footprint
✅ Single Speed Operation – Fixed speed for consistent, reliable circulation
✅ SilentFlo Replacement – Direct replacement for Watkins SilentFlo 5000 and 5002
✅ ¾-Inch Smooth Barb – Easy connection to flexible vinyl hose
✅ Continuous Operation – Designed for 24/7 spa circulation
✅ Efficient Water Flow – Effective circulation with minimal power draw
✅ No Cord Supplied – Use your existing 3-core cable
✅ Dual Brand Heritage – Laing / Goulds quality engineering
🔧 Technical Specifications
| Specification | Value |
|---|---|
| Pump Type | Circulation Pump – Fixed Speed |
| Brand | Laing / Goulds |
| Model | E5 SilentFlo |
| Motor Power | 0.039 kW (39W) |
| Horsepower | 0.05 HP |
| Speed Settings | Single Speed (Fixed) |
| Amperage | 0.2 A |
| Plumbing Size | ¾ inch (3/4″) |
| Connection Type | Smooth Barb |
| Cord Type | Not supplied – use existing 3-core cable |
| Length | 135 mm |
| Width | 90 mm |
| Height | 115 mm |
⚡ Electrical Requirements
| Electrical Specification | Requirement |
|---|---|
| Power Output | 0.039 kW (39W) |
| Horsepower | 0.05 HP |
| Full Load Amps | 0.2 A |
| Cord Type | Not supplied |
⚠️ IMPORTANT ELECTRICAL SAFETY:
All electrical work must be carried out by a qualified electrician in accordance with UK wiring regulations (BS 7671). Hot tubs require RCD protection (30mA). Ensure proper earthing and bonding of all electrical components. The pump is supplied without a power cord – your existing 3-core cable can be reused from your old circulation pump.
🔗 Compatibility Guide
This Pump Specifications:
📍 Model: Laing / Goulds E5 SilentFlo 📍 Connection: ¾ inch (3/4″) Smooth Barb 📍 Power: 0.039 kW (39W) / 0.2A 📍 Dimensions: 135mm × 90mm × 115mm
Replaces:
This pump is a direct replacement for:
- Watkins SilentFlo® 5000 (Part No: 74428)
- Watkins SilentFlo 5002 (Part No: 74427)
Compatible Spa Brands:
Suitable for spas that use the Watkins SilentFlo circulation system, including:
- Hot Spring Spas
- Tiger River Spas
- Other Watkins-manufactured hot tubs
Connection Note:
The ¾-inch smooth barb connections are designed for use with flexible vinyl hose. Secure connections with appropriate hose clamps for a leak-free seal.
⚙️ Installation Requirements
Pump Dimensions:
| Dimension | Measurement |
|---|---|
| Length | 135 mm |
| Width | 90 mm |
| Height | 115 mm |
Plumbing Connections:
| Connection | Size | Type |
|---|---|---|
| Inlet | ¾ inch | Smooth Barb |
| Outlet | ¾ inch | Smooth Barb |
Installation Notes:
⚠️ Use ¾” vinyl hose with metal pipe clamps for secure connection
⚠️ Heat vinyl pipe ends before fitting to barbs for better seal
⚠️ Pump must be installed below water level (flooded suction)
⚠️ Never run the pump dry
⚠️ Ensure proper electrical bonding to earth
⚠️ Pump supplied without cord – reuse existing cable or purchase separately
💡 Ultra-compact design fits in the tightest equipment bays
💡 Direct replacement for SilentFlo pumps – same mounting and connections
🛠️ Maintenance Guide
Routine Maintenance:
| Task | Frequency | Notes |
|---|---|---|
| Check for leaks | Monthly | Inspect barb connections and hose clamps |
| Inspect hose clamps | Monthly | Tighten if necessary |
| Verify pump operation | Weekly | Ensure pump is running when expected |
| Check water flow | Monthly | Verify adequate circulation |
| Inspect vinyl hose | Quarterly | Replace if cracked or deteriorated |
Warning Signs – Consider Replacement If:
- Unusual noise or vibration
- Motor fails to start
- Noticeably reduced water flow
- Motor overheating
- Pump trips the circuit breaker
🎯 Ideal Applications
| Application | Suitability | Notes |
|---|---|---|
| ♨️ Hot Tub Circulation | Yes | Primary application for 24/7 circulation |
| ♨️ Spa Filtration Loop | Yes | Continuous filtration and heating |
| ♨️ SilentFlo 5000 Replacement | Yes | Direct drop-in replacement |
| ♨️ SilentFlo 5002 Replacement | Yes | Direct drop-in replacement |
| ♨️ Hot Spring Spas | Yes | Common OEM circulation pump |
| ♨️ Tiger River Spas | Yes | Common OEM circulation pump |
| ♨️ Ultra-Compact Installations | Yes | Smallest footprint at 135×90×115mm |
| ♨️ Energy-Conscious Spas | Yes | Ultra-low 0.2A / 39W consumption |
❓ Frequently Asked Questions
Q: What is the power rating of this pump? A: The Laing E5 is rated at 0.039 kW (39W) / 0.05 HP, making it one of the most energy-efficient circulation pumps available.
Q: How much current does this pump draw? A: The E5 draws only 0.2A, making it extremely economical to run 24 hours a day.
Q: Is this the correct replacement for my SilentFlo pump? A: Yes, the Laing E5 is a direct replacement for the Watkins SilentFlo® 5000 (part number 74428) and SilentFlo 5002 (part number 74427).
Q: What size are the plumbing connections? A: The pump uses ¾-inch (3/4″) smooth barb connections, designed for use with flexible vinyl hose.
Q: Does this pump come with a power cord? A: No, the pump is supplied without a power cord. You can reuse your existing 3-core cable from the old pump, or purchase a new cable separately.
Q: What are the dimensions of this pump? A: The E5 measures 135mm (length) × 90mm (width) × 115mm (height), making it extremely compact.
Q: What spa brands use this pump? A: The E5 SilentFlo is commonly used as a replacement in Hot Spring, Tiger River, and other Watkins-manufactured spas.
Q: Is this pump suitable for continuous 24/7 operation? A: Yes, the Laing E5 is specifically designed for continuous operation in spa circulation systems.
Q: How do I know if my circulation pump needs replacing? A: Signs include the motor failing to start, unusual noises, reduced water flow, or the pump tripping the circuit breaker.
🏆 Why Choose the Laing E5 SilentFlo Circulation Pump
✅ Ultra-Efficient – Just 0.2A / 39W for minimal running costs
✅ Most Compact – Tiny 135mm × 90mm × 115mm footprint
✅ Direct Replacement – Drop-in for SilentFlo 5000 and 5002
✅ Proven Quality – Laing / Goulds engineering heritage
✅ Easy Installation – Same connections as original pump
✅ 24/7 Reliable – Designed for continuous operation
✅ Whisper Quiet – SilentFlo name says it all
🤝 Why Buy From Parts4Tubs
✅ UK-based company with expert local support
✅ Fast UK delivery options available
✅ Knowledgeable advice from spa industry specialists
✅ Competitive pricing
✅ Full warranty support
✅ Replacement cables and hose clamps available
✅ Easy returns within 30 days
✨ Summary
The Laing / Goulds E5 SilentFlo Circulation Pump is an ultra-compact, highly efficient circulation pump designed for continuous 24/7 operation in spas and hot tubs. Drawing just 0.2A at 0.039 kW (39W / 0.05 HP), this is one of the most energy-efficient circulation pumps available. The ultra-compact dimensions (135mm × 90mm × 115mm) make it ideal for tight installations. Features ¾-inch smooth barb connections for easy plumbing integration. Direct replacement for Watkins SilentFlo® 5000 (74428) and SilentFlo 5002 (74427) circulation pumps, making it the perfect choice for Hot Spring, Tiger River, and other Watkins-manufactured spas. Supplied without power cord – your existing 3-core cable can be reused.
Filters Sort Reset Apply
The hot tub industry doesnt make it easy for you when you are trying to match up the size of the unions (the part that screws your pipe work onto the pumps) Below you can see the physical sizes of the collars, and how they relate to the actual union size you need. So a measurement of 2.5", edge to edge on the collar of the pump is actually a 1.5" union - confusing - absolutely! If you are not sure, give me a shout!
Hot Tub Pump Collar & Union Size Chart
Hot Tub Pump Collar & Union Size Chart
Imperial & Metric Specifications
Union Size
Collar Size
Thread OD
Union OD
O-Ring Size
1.5"
Female Buttress
Thread (FBT)
2.5" / 64mm
(Tip to Tip)
Measurement
2-1/2"
64mm
2-13/16"
71mm
2-5/16" OD
59mm
2"
Female Buttress
Thread (FBT)
3.1" / 78mm
(Tip to Tip)
Measurement
3-1/16"
78mm
3-3/8"
81mm
2-15/16" OD
75mm
2.5"
Female Buttress
Thread (FBT)
3.6" / 91mm
(Tip to Tip)
Measurement
3-5/8"
91mm
4-1/4"
108mm
3-7/16" OD
87mm
Important Notes
The union "size" (1.5", 2", 2.5") is nominal and doesn't correspond to any actual measurement.
Collar size is measured from thread tip to thread tip on the pump outlet.
Most hot tub pumps use Female Buttress Thread (FBT) - 98% of applications.
O-ring gaskets may vary between manufacturers - measure your existing gasket for accuracy.
How do I Replace a Hot Tub Pump?
Here's a general step-by-step guide on how to replace a hot tub pump. Keep in mind that the specific steps may vary depending on your hot tub's make and model, so it's essential to consult your hot tub's manual for model-specific instructions. If you're not comfortable with this procedure, it's a good idea to seek professional assistance.
Materials You'll Need:
- Replacement pump
- Pipe wrench
- Adjustable wrench
- Screwdriver
- Pipe sealant (thread tape or plumber's putty)
- PVC primer and cement (if you have PVC plumbing)
- Teflon tape (for threaded connections)
Procedure:
- Turn Off the Power: Before you begin, ensure the hot tub's power supply is turned off at the circuit breaker or disconnect switch. Safety should always be a priority when working with electrical components.
- Drain the Hot Tub: If your hot tub is not already empty, you'll need to drain it. Follow your hot tub's manual or manufacturer's instructions for proper draining. (You might not need to do this if you can lock the pump off with the gate valves)
- Locate the Pump: Identify the location of the existing pump in your hot tub. It's usually located near the equipment area or in a designated pump compartment.
- Disconnect the Electrical Wiring: Carefully disconnect the electrical wiring from the old pump. This typically involves removing the electrical conduit cover, unscrewing wire nuts, and disconnecting the wires from the terminals. Be sure to note the wire connections or take a picture for reference when connecting the new pump.
- Disconnect the Plumbing: Depending on your hot tub's plumbing setup, you'll need to disconnect the plumbing connections to the pump. Use a pipe wrench or adjustable wrench to loosen and remove the fittings. Be prepared for some water spillage when disconnecting the plumbing.
- Remove the Old Pump: Once the electrical and plumbing connections are detached, carefully remove the old pump from its mounting position. Some pumps may be secured with mounting brackets or bolts.
- Prepare the New Pump: If the new pump is not pre-assembled, you may need to attach fittings, unions, or adapters to match your hot tub's plumbing. Ensure that you use the appropriate sealant or Teflon tape on threaded connections to prevent leaks.
- Mount the New Pump: Position the new pump in the same location as the old one and secure it in place using the mounting brackets or bolts.
- Reconnect Plumbing: Reconnect the plumbing to the new pump, ensuring that all connections are tight and secure. If your hot tub uses PVC plumbing, use PVC primer and cement to bond the connections properly.
- Reconnect Electrical Wiring: Reconnect the electrical wiring to the new pump, following the notes or pictures you took earlier. Make sure all wires are properly connected and secure.
- Turn On the Power: Restore power to the hot tub by switching on the circuit breaker or reconnecting the disconnect switch.
- Test the Pump: Turn on the hot tub's pump to ensure that it's working correctly. Check for any signs of leaks or irregularities in the plumbing connections.
- Refill the Hot Tub: Once you've confirmed that the new pump is functioning properly, refill the hot tub with water.
- Check for Leaks: Inspect the plumbing connections for any leaks. If you find any, turn off the pump, drain the tub again, and reseal the connections as needed.
- Monitor: Keep an eye on the pump and plumbing for the next few days to ensure everything is functioning correctly and that there are no further issues.
Remember that this is a general guideline, and the specific steps may vary based on your hot tub's design. If you're unsure or uncomfortable with any aspect of this process, please do get in touch, happy to help.
How do I know what size hot tub pump I have?
Determining the size of your hot tub pump is an important step when it comes to maintenance or replacement. To find out the size of your hot tub pump, follow these steps:
- Check the Manual: The easiest way to determine the size of your hot tub pump is to consult the owner's manual or user documentation that came with your hot tub. The manual typically contains detailed information about the specifications and components of your hot tub, including the pump.
- Look at the Pump Housing: If you don't have access to the manual or it doesn't provide the information you need, inspect the pump itself. Most hot tub pumps have a label or plate on the pump housing that displays essential details, including the pump's model number, manufacturer, and specifications. You can then send that to me or Google it.
- Measure the Pump: If the label is missing or damaged, you can measure the pump's dimensions. Measure the diameter of the pump's wet end (the part where the water flows) and the length of the wet end. These measurements can help identify the size and capacity of the pump.
- Consult the Manufacturer: If you can't find the information on the pump or in the manual, contact the hot tub manufacturer or a reputable dealer. Provide them with your hot tub's model and serial number, and they should be able to identify the correct pump size for your specific hot tub.
- Online Research: You can also search online using the pump's model number or hot tub's make and model. Many manufacturers provide detailed information about their products on their websites, and you may find specifications for your pump model.
Once you have determined the size and specifications of your hot tub pump, you can proceed with maintenance, repairs, or replacement if necessary. Keep in mind that replacing a hot tub pump with the same size and capacity as the original is crucial to ensure proper water circulation and filtration in your hot tub. If you're unsure about any aspect of this process, get in touch, always happy to help.
Hot Tub Pump Collar & Union Size Chart
| Union Size | Collar Size | Thread OD | Union OD | O-Ring Size |
|---|---|---|---|---|
|
1.5"
Female Buttress
Thread (FBT) |
2.5" / 64mm
(Tip to Tip)
Measurement |
2-1/2"
64mm
|
2-13/16"
71mm
|
2-5/16" OD
59mm
|
|
2"
Female Buttress
Thread (FBT) |
3.1" / 78mm
(Tip to Tip)
Measurement |
3-1/16"
78mm
|
3-3/8"
81mm
|
2-15/16" OD
75mm
|
|
2.5"
Female Buttress
Thread (FBT) |
3.6" / 91mm
(Tip to Tip)
Measurement |
3-5/8"
91mm
|
4-1/4"
108mm
|
3-7/16" OD
87mm
|









