Fernox TF1 Sigma Mini Filter 3/4" BSP – Compact Magnetic Boiler Filter for Central Heating Systems
Keep Your Heating System Clean and Efficient
If you’ve ever dealt with boiler sludge, poor circulation, or noisy radiators, you know how frustrating it can be. Over time, heating systems collect magnetite, rust, and debris that can damage components and reduce efficiency.
The Fernox TF1 Sigma Mini Filter 3/4" BSP is designed to help stop that problem before it starts.
This high-performance magnetic central heating filter captures harmful debris before it reaches your boiler, pumps, or valves. The result is better efficiency, longer system life, and fewer costly repairs.
Whether you’re a heating engineer installing a new system or a homeowner protecting an existing one, this compact filter is a reliable solution.
Why Choose the Fernox TF1 Sigma Mini Filter?
The Fernox TF1 Sigma Mini is trusted by installers because it combines powerful filtration with a compact design. Unlike bulky system filters, the Sigma Mini is built to fit easily into tight spaces while still delivering excellent debris capture.
Key Benefits
Powerful Magnetic Filtration – Captures magnetite and sludge that can damage boilers and heating components.
Hydronic Particle Separation – Removes both magnetic and non-magnetic debris from the system.
Compact Design – Ideal for tight installations where space is limited.
3/4" BSP Connections – Compatible with many domestic heating systems.
Quick & Easy Cleaning – The removable magnet allows fast servicing without dismantling the unit.
Improves System Efficiency – Cleaner water helps improve circulation and heating performance.
Extends Boiler Life – Helps protect heat exchangers, pumps, and valves.
Designed for Modern Heating Systems
The TF1 Sigma Mini Filter was engineered with installers in mind. It delivers strong filtration performance without taking up valuable space around the boiler.
The filter works by combining magnetic filtration for magnetite, hydrodynamic separation for non-magnetic debris, and easy service access for quick maintenance.
This helps keep your central heating system running smoothly year after year.
Product Specifications
Product
Fernox TF1 Sigma Mini Filter
Connection Size
3/4" BSP
Type
Magnetic central heating system filter
Application
Domestic heating systems
Installation
In-line filter for central heating pipework
Maintenance
Quick-clean magnetic core
Brand
Fernox
What Problems Does This Filter Help Prevent?
Many heating issues come from system contamination. Installing a Fernox TF1 Sigma Mini can help reduce the risk of:
Boiler breakdowns caused by sludge
Blocked heat exchangers
Circulation problems
Cold spots on radiators
Pump damage
Reduced heating efficiency
Who Is This Product For?
The Fernox TF1 Sigma Mini Filter 3/4" BSP is ideal for:
Heating engineers and installers
Boiler replacement installations
Central heating upgrades
Homeowners protecting their boiler
Landlords maintaining heating systems
If you're installing a new boiler, adding a magnetic filter is one of the best ways to protect your investment.
Installation Made Simple
One thing installers appreciate about the TF1 Sigma Mini is how easy it is to fit. The compact body and flexible orientation mean it can be installed vertically or horizontally depending on the pipe layout.
Maintenance is also straightforward:
Isolate the filter
Remove the magnet
Flush out captured debris
Replace the magnet and close
The whole process takes just minutes.
Why Magnetic Filters Are Important for Boilers
Modern boilers have narrow heat exchangers, which makes them efficient but also more vulnerable to sludge. Without a filter, magnetite can build up and lead to reduced heating performance, higher energy bills, and expensive repairs.
A magnetic system filter like the Fernox TF1 Sigma Mini acts as a first line of defence.
Why Fernox Is Trusted by Installers
Fernox is one of the most respected brands in central heating water treatment and system protection. Installers trust Fernox because their products are built for professional use, tested for long-term reliability, and designed to improve heating efficiency.
The TF1 Sigma range is widely used in both new installations and system upgrades.
Key Features at a Glance
Compact magnetic system filter
High-performance debris capture
Suitable for 3/4" BSP pipe connections
Quick cleaning magnetic core
Ideal for tight boiler installations
Protects boilers and heating components
Improves heating efficiency
Frequently Asked Questions
Do I need a magnetic filter for my boiler?
Most heating professionals recommend installing a magnetic system filter to help prevent sludge build-up and protect modern boilers.
How often should the filter be cleaned?
It is usually cleaned during annual boiler servicing, although heavily contaminated systems may need more frequent attention.
Can this be installed on existing heating systems?
Yes, the TF1 Sigma Mini can be installed on both new and existing central heating systems.
Order Your Fernox TF1 Sigma Mini Filter Today
Protect your heating system before sludge causes expensive damage.
The Fernox TF1 Sigma Mini Filter 3/4" BSP offers powerful filtration in a compact, installer-friendly design, making it a strong choice for modern central heating systems.
Add it to your system today and enjoy cleaner water, better efficiency, and longer boiler life.
Delivery Times
All our deliveries are made by some of the countries most trusted couriers, including Royal Mail, PacelForce, DHL , Fastway Curriers
For most larger sized deliveries, you will receive a call from the courier an hour before the scheduled delivery time.
Free Delivery
Free delivery when you spend £150+ on all our stocked items, up to the maximum 20kg in weight (UK & Ireland Only) To be eligible for this service, you must place your order before 1pm on the previous day.
Delivery Drop Off
It is important to note that we use external shipping couriers. They are responsible for delivering the item(s) to the kerb-side. They are not responsible for delivering items into your home*.
*Please note, for large orders we advise that you seek assistance from friends or neighbours to assist with moving your order, as often the driver will not be able to assist you. Some items may be delivered on a pallet. It is your responsibility to dispose of the pallet, however, we recommend keeping it for the first 14 days in case you need to return your item(s).
Failed Deliveries
In the unlikely event that delivery is attempted when you are not at home, we will contact you by phone and re-book another time that suits you. Please note, there may be a re-delivery charge added at our discretion, which will be reviewed on a case by case basis.
Direct Deliveries from Distribution Centers
To help you receive your items as quickly as possible, parts of your order may be dispatched directly from a distribution center (Ie) Amazon. If this is the case, you will be contacted directly by them to arrange delivery for the products concerned. Please note, these items will arrive at a different time to products dispatched from our head warehouse. Some distribution centers may take between 2-3 days to deliver items.
Non-Stocked Items
Some items are ordered into our warehouse especially for your orders. This means there may be additional lead times on your order arriving. The estimated delivery time for non-stocked items is 5-7 working days.
For orders that contain a mixture of stock and non-stock items, excluding items delivered directly from distribution centers, we will deliver all items together. We will make you aware of this when we phone or email you to confirm the delivery date. You will be given the option to receive them separately as well, however there may be additional shipping charges.
Shipping Rates
All Orders to the UK & Ireland *ONLY*up to 20kg £150+ is Free
Pallet Rates are priced on application and order... delivery lead times will also vary based on post code.
Returns
Returns are subject too a 50% re-stocking charge.
- Items installed/fitted without professional understanding IE Oftec/SafeGas Registered Installer certificates, invalidate any warranty of said item bought.. This is however is at the companies discretion.
- All products must be inspected within 24hrs. Goods are non-returnable after this period.
To be eligible for a return, your item must be unused and in the same condition that you received it. It must also be in the original packaging.
Several types of goods are exempt from being returned. Goods including but not limited to printed circuit boards, control boxes, chemicals, hazardous materials, flammable liquids or gases. Please ask if you are unsure if you can return your goods.
Some items are not returnable such as PCB Boards and Boilers if they are opened, There also will be a 25% Handling fee for All Items if accepted for return.
To complete your return, we require a receipt or proof of purchase.
Please do not send your purchase back to the manufacturer unless otherwise instructed by Spares Direct.
There are certain situations where only partial refunds are granted (if applicable) Any item not in its original condition, is damaged or missing parts for reasons not due to manufacturer / supplier error Any item that is returned more than 30 days after delivery
Refunds (if applicable) Once your return is received and inspected, we will send you an email to notify you that we have received your returned item. We will also notify you of the approval or rejection of your refund. If you are approved, then your refund will be processed, and a credit will automatically be applied to your credit card or original method of payment, within a certain amount of days.
Late or missing refunds (if applicable) If you haven’t received a refund yet, first check your bank account again. Then contact your credit card company, it may take some time before your refund is officially posted. Next contact your bank. There is often some processing time before a refund is posted. If you’ve done all of this and you still have not received your refund, please contact us at info@sparesdirect.ie
Sale items (if applicable) Only regular priced items may be refunded, unfortunately sale items cannot be refunded.
Exchanges (if applicable) We only replace items if they are defective or damaged. If you need to exchange it for the same item, send us an email at info@sparesdirect.ie and send your item to: Unit 5 Dargan Industrial Park, 62 Dargan Crescent, Belfast BT3 9JP.
Unwanted goods or Failed deliveries of items bought If for any reason you order from us and the item has been shipped, but you no longer wish to have the item, the goods should be returned to us at the consumers cost. The price of goods will be refunded upon delivery/inspection (please note carriage cost will NOT be refunded. This also applies to missed deliveries/collection of goods from currier depot.
Shipping To return your product, you should mail your product to: Unit 5 Dargan Industrial Park, 62 Dargan Crescent, Belfast BT3 9JP.
You will be responsible for paying for your own shipping costs for returning your item. Shipping costs are non-refundable. If you receive a refund, the cost of return shipping will be deducted from your refund.
Depending on where you live, the time it may take for your exchanged product to reach you, may vary.
If you are shipping an item over £50, you should consider using a trackable shipping service or purchasing shipping insurance. We don’t guarantee that we will receive your returned item.
Fernox TF1 Sigma Mini Filter 3/4" BSP – Compact Magnetic Boiler Filter for Central Heating Systems
Keep Your Heating System Clean and Efficient
If you’ve ever dealt with boiler sludge, poor circulation, or noisy radiators, you know how frustrating it can be. Over time, heating systems collect magnetite, rust, and debris that can damage components and reduce efficiency.
The Fernox TF1 Sigma Mini Filter 3/4" BSP is designed to help stop that problem before it starts.
This high-performance magnetic central heating filter captures harmful debris before it reaches your boiler, pumps, or valves. The result is better efficiency, longer system life, and fewer costly repairs.
Whether you’re a heating engineer installing a new system or a homeowner protecting an existing one, this compact filter is a reliable solution.
Why Choose the Fernox TF1 Sigma Mini Filter?
The Fernox TF1 Sigma Mini is trusted by installers because it combines powerful filtration with a compact design. Unlike bulky system filters, the Sigma Mini is built to fit easily into tight spaces while still delivering excellent debris capture.
Key Benefits
Powerful Magnetic Filtration – Captures magnetite and sludge that can damage boilers and heating components.
Hydronic Particle Separation – Removes both magnetic and non-magnetic debris from the system.
Compact Design – Ideal for tight installations where space is limited.
3/4" BSP Connections – Compatible with many domestic heating systems.
Quick & Easy Cleaning – The removable magnet allows fast servicing without dismantling the unit.
Improves System Efficiency – Cleaner water helps improve circulation and heating performance.
Extends Boiler Life – Helps protect heat exchangers, pumps, and valves.
Designed for Modern Heating Systems
The TF1 Sigma Mini Filter was engineered with installers in mind. It delivers strong filtration performance without taking up valuable space around the boiler.
The filter works by combining magnetic filtration for magnetite, hydrodynamic separation for non-magnetic debris, and easy service access for quick maintenance.
This helps keep your central heating system running smoothly year after year.
Product Specifications
Product
Fernox TF1 Sigma Mini Filter
Connection Size
3/4" BSP
Type
Magnetic central heating system filter
Application
Domestic heating systems
Installation
In-line filter for central heating pipework
Maintenance
Quick-clean magnetic core
Brand
Fernox
What Problems Does This Filter Help Prevent?
Many heating issues come from system contamination. Installing a Fernox TF1 Sigma Mini can help reduce the risk of:
Boiler breakdowns caused by sludge
Blocked heat exchangers
Circulation problems
Cold spots on radiators
Pump damage
Reduced heating efficiency
Who Is This Product For?
The Fernox TF1 Sigma Mini Filter 3/4" BSP is ideal for:
Heating engineers and installers
Boiler replacement installations
Central heating upgrades
Homeowners protecting their boiler
Landlords maintaining heating systems
If you're installing a new boiler, adding a magnetic filter is one of the best ways to protect your investment.
Installation Made Simple
One thing installers appreciate about the TF1 Sigma Mini is how easy it is to fit. The compact body and flexible orientation mean it can be installed vertically or horizontally depending on the pipe layout.
Maintenance is also straightforward:
Isolate the filter
Remove the magnet
Flush out captured debris
Replace the magnet and close
The whole process takes just minutes.
Why Magnetic Filters Are Important for Boilers
Modern boilers have narrow heat exchangers, which makes them efficient but also more vulnerable to sludge. Without a filter, magnetite can build up and lead to reduced heating performance, higher energy bills, and expensive repairs.
A magnetic system filter like the Fernox TF1 Sigma Mini acts as a first line of defence.
Why Fernox Is Trusted by Installers
Fernox is one of the most respected brands in central heating water treatment and system protection. Installers trust Fernox because their products are built for professional use, tested for long-term reliability, and designed to improve heating efficiency.
The TF1 Sigma range is widely used in both new installations and system upgrades.
Key Features at a Glance
Compact magnetic system filter
High-performance debris capture
Suitable for 3/4" BSP pipe connections
Quick cleaning magnetic core
Ideal for tight boiler installations
Protects boilers and heating components
Improves heating efficiency
Frequently Asked Questions
Do I need a magnetic filter for my boiler?
Most heating professionals recommend installing a magnetic system filter to help prevent sludge build-up and protect modern boilers.
How often should the filter be cleaned?
It is usually cleaned during annual boiler servicing, although heavily contaminated systems may need more frequent attention.
Can this be installed on existing heating systems?
Yes, the TF1 Sigma Mini can be installed on both new and existing central heating systems.
Order Your Fernox TF1 Sigma Mini Filter Today
Protect your heating system before sludge causes expensive damage.
The Fernox TF1 Sigma Mini Filter 3/4" BSP offers powerful filtration in a compact, installer-friendly design, making it a strong choice for modern central heating systems.
Add it to your system today and enjoy cleaner water, better efficiency, and longer boiler life.
Delivery Times
All our deliveries are made by some of the countries most trusted couriers, including Royal Mail, PacelForce, DHL , Fastway Curriers
For most larger sized deliveries, you will receive a call from the courier an hour before the scheduled delivery time.
Free Delivery
Free delivery when you spend £150+ on all our stocked items, up to the maximum 20kg in weight (UK & Ireland Only) To be eligible for this service, you must place your order before 1pm on the previous day.
Delivery Drop Off
It is important to note that we use external shipping couriers. They are responsible for delivering the item(s) to the kerb-side. They are not responsible for delivering items into your home*.
*Please note, for large orders we advise that you seek assistance from friends or neighbours to assist with moving your order, as often the driver will not be able to assist you. Some items may be delivered on a pallet. It is your responsibility to dispose of the pallet, however, we recommend keeping it for the first 14 days in case you need to return your item(s).
Failed Deliveries
In the unlikely event that delivery is attempted when you are not at home, we will contact you by phone and re-book another time that suits you. Please note, there may be a re-delivery charge added at our discretion, which will be reviewed on a case by case basis.
Direct Deliveries from Distribution Centers
To help you receive your items as quickly as possible, parts of your order may be dispatched directly from a distribution center (Ie) Amazon. If this is the case, you will be contacted directly by them to arrange delivery for the products concerned. Please note, these items will arrive at a different time to products dispatched from our head warehouse. Some distribution centers may take between 2-3 days to deliver items.
Non-Stocked Items
Some items are ordered into our warehouse especially for your orders. This means there may be additional lead times on your order arriving. The estimated delivery time for non-stocked items is 5-7 working days.
For orders that contain a mixture of stock and non-stock items, excluding items delivered directly from distribution centers, we will deliver all items together. We will make you aware of this when we phone or email you to confirm the delivery date. You will be given the option to receive them separately as well, however there may be additional shipping charges.
Shipping Rates
All Orders to the UK & Ireland *ONLY*up to 20kg £150+ is Free
Pallet Rates are priced on application and order... delivery lead times will also vary based on post code.
Returns
Returns are subject too a 50% re-stocking charge.
- Items installed/fitted without professional understanding IE Oftec/SafeGas Registered Installer certificates, invalidate any warranty of said item bought.. This is however is at the companies discretion.
- All products must be inspected within 24hrs. Goods are non-returnable after this period.
To be eligible for a return, your item must be unused and in the same condition that you received it. It must also be in the original packaging.
Several types of goods are exempt from being returned. Goods including but not limited to printed circuit boards, control boxes, chemicals, hazardous materials, flammable liquids or gases. Please ask if you are unsure if you can return your goods.
Some items are not returnable such as PCB Boards and Boilers if they are opened, There also will be a 25% Handling fee for All Items if accepted for return.
To complete your return, we require a receipt or proof of purchase.
Please do not send your purchase back to the manufacturer unless otherwise instructed by Spares Direct.
There are certain situations where only partial refunds are granted (if applicable) Any item not in its original condition, is damaged or missing parts for reasons not due to manufacturer / supplier error Any item that is returned more than 30 days after delivery
Refunds (if applicable) Once your return is received and inspected, we will send you an email to notify you that we have received your returned item. We will also notify you of the approval or rejection of your refund. If you are approved, then your refund will be processed, and a credit will automatically be applied to your credit card or original method of payment, within a certain amount of days.
Late or missing refunds (if applicable) If you haven’t received a refund yet, first check your bank account again. Then contact your credit card company, it may take some time before your refund is officially posted. Next contact your bank. There is often some processing time before a refund is posted. If you’ve done all of this and you still have not received your refund, please contact us at info@sparesdirect.ie
Sale items (if applicable) Only regular priced items may be refunded, unfortunately sale items cannot be refunded.
Exchanges (if applicable) We only replace items if they are defective or damaged. If you need to exchange it for the same item, send us an email at info@sparesdirect.ie and send your item to: Unit 5 Dargan Industrial Park, 62 Dargan Crescent, Belfast BT3 9JP.
Unwanted goods or Failed deliveries of items bought If for any reason you order from us and the item has been shipped, but you no longer wish to have the item, the goods should be returned to us at the consumers cost. The price of goods will be refunded upon delivery/inspection (please note carriage cost will NOT be refunded. This also applies to missed deliveries/collection of goods from currier depot.
Shipping To return your product, you should mail your product to: Unit 5 Dargan Industrial Park, 62 Dargan Crescent, Belfast BT3 9JP.
You will be responsible for paying for your own shipping costs for returning your item. Shipping costs are non-refundable. If you receive a refund, the cost of return shipping will be deducted from your refund.
Depending on where you live, the time it may take for your exchanged product to reach you, may vary.
If you are shipping an item over £50, you should consider using a trackable shipping service or purchasing shipping insurance. We don’t guarantee that we will receive your returned item.
Rückerstattungsrichtlinien
Returns
Returns are subject too a 50% re-stocking charge.
- Items installed/fitted without professional understanding IE Oftec/SafeGas Registered Installer certificates, invalidate any warranty of said item bought.. This is however is at the companies discretion.
- All products must be inspected within 24hrs. Goods are non-returnable after this period.
To be eligible for a return, your item must be unused and in the same condition that you received it. It must also be in the original packaging.
Several types of goods are exempt from being returned. Goods including but not limited to printed circuit boards, control boxes, chemicals, hazardous materials, flammable liquids or gases. Please ask if you are unsure if you can return your goods.
Some items are not returnable such as PCB Boards and Boilers if they are opened, There also will be a 25% Handling fee for All Items if accepted for return.
To complete your return, we require a receipt or proof of purchase.
Please do not send your purchase back to the manufacturer unless otherwise instructed by Spares Direct.
There are certain situations where only partial refunds are granted (if applicable) Any item not in its original condition, is damaged or missing parts for reasons not due to manufacturer / supplier error Any item that is returned more than 30 days after delivery
Refunds (if applicable) Once your return is received and inspected, we will send you an email to notify you that we have received your returned item. We will also notify you of the approval or rejection of your refund. If you are approved, then your refund will be processed, and a credit will automatically be applied to your credit card or original method of payment, within a certain amount of days.
Late or missing refunds (if applicable) If you haven’t received a refund yet, first check your bank account again. Then contact your credit card company, it may take some time before your refund is officially posted. Next contact your bank. There is often some processing time before a refund is posted. If you’ve done all of this and you still have not received your refund, please contact us at info@sparesdirect.ie
Sale items (if applicable) Only regular priced items may be refunded, unfortunately sale items cannot be refunded.
Exchanges (if applicable) We only replace items if they are defective or damaged. If you need to exchange it for the same item, send us an email at info@sparesdirect.ie and send your item to: Unit 5 Dargan Industrial Park, 62 Dargan Crescent, Belfast BT3 9JP.
Unwanted goods or Failed deliveries of items bought If for any reason you order from us and the item has been shipped, but you no longer wish to have the item, the goods should be returned to us at the consumers cost. The price of goods will be refunded upon delivery/inspection (please note carriage cost will NOT be refunded. This also applies to missed deliveries/collection of goods from currier depot.
Shipping To return your product, you should mail your product to: Unit 5 Dargan Industrial Park, 62 Dargan Crescent, Belfast BT3 9JP.
You will be responsible for paying for your own shipping costs for returning your item. Shipping costs are non-refundable. If you receive a refund, the cost of return shipping will be deducted from your refund.
Depending on where you live, the time it may take for your exchanged product to reach you, may vary.
If you are shipping an item over £50, you should consider using a trackable shipping service or purchasing shipping insurance. We don’t guarantee that we will receive your returned item.
Info@sparesdirect.ie
02895 434 399
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