Fernox F4 Central Heating Leak Sealer 500ml

By Fernox Product code: 92490 Pack size: Each

£11.98 was £16.98 Exc. VAT £9.98
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Product Details

Seals small leaks and weeps which may cause pressure loss and/or boiler breakdown.


An internal leak sealer developed for use throughout a central heating system to seal small, inaccessible leaks and weeps which may cause pressure loss and boiler breakdown. Once dispersed within the system, the product finds the area of oxygen ingress and forms a polymer to seal the pinhole. Effective within 1-24 hours after application, the unique sealing efficiency of this water treatment chemical has been proven to prevent blockages or restrictions within the boiler or vulnerable system components such as pumps and safety devices. A leak can be quickly and efficiently sealed, without the need for a complete system drain down.

• Ideal for reducing pressure loss from sealed systems
• Seals most weeps and small inaccessible leaks
• Compatible with all metals and materials commonly used in central heating systems
• One 500ml recyclable bottle treats up to 130 litres of system water (16 radiators) and the equivalent of 250m2 of underfloor systems.

Technical Specification
Brand Fernox
Safety Data Sheet click here
Volume (L) 0.5
Delivery details
 

DELIVERY OPTIONS (UK mainland only)

Next Day Delivery – £5.00 or FREE for orders over £25

  • Order before 9pm Monday to Thursday for next business day delivery
  • Order Friday to Sunday before 6pm for Monday delivery
  • Orders placed after Sunday at 6pm will be delivered the following Tuesday
Pre-12pm Delivery – £10.00 or £5.00 for orders over £25, to arrive before 12pm on the scheduled days above

Saturday Delivery – £10.00 or £5.00 for orders over £25 & FREE for orders over £75 (order by 6pm Friday)

Sunday delivery – £10.00 or £5.00 for orders over £25 & FREE for orders over £75 (order by 4pm Saturday)

Times may vary for items being delivered directly from the supplier. For more information, please visit our delivery information page Items over 30kg can only be delivered next Business Day Mon-Fri. Orders placed after 9pm Thursday will be delivered the following Monday
More about Delivery & Returns
Click & Collect details

Collection Details

We are fully open and delighted to welcome our customers into our branches. Our opening times are 7am-8pm Monday-Friday, 7am-7pm Saturday and 9-4pm Sunday

We advise that you check your local branch is open on the branch locator page, before you visit.

Once you have placed your order online, we’ll have it ready for you at the branch you have selected in as little as 5 minutes. We will hold your order for 14 days, after which we will automatically generate a refund to the payment type you used to place the order.

Please wait for your text or email before coming to collect it and be aware that we will still have health & safety measures in place, so we ask that you observe the branch guidelines.

Don’t forget your mobile number – Please ensure that your mobile number is added so that we can text you when your order is ready to collect.

Reviews
Fernox F4 Central Heating Leak Sealer 500ml is rated 4.7 out of 5 by 72.
Rated 5 out of 5 by from This works! Basically it works! One application and an annoying seepage, stopped!
Date published: 2021-07-27
Rated 5 out of 5 by from Leak sealer It works simple as that ! Had my doubts as had small leak from towel rail to thermostat valve, not even a welded joint so rather than draining and tightening fixture tried this and it solved the problem - Simples
Date published: 2021-07-17
Rated 4 out of 5 by from Straight forward to use Works well. Fixed my leak.
Date published: 2021-07-14
Rated 5 out of 5 by from Excellent job Did the job and helped reseal the system and keep the pressure up....
Date published: 2021-07-13
Rated 5 out of 5 by from Retired plumber Excellent stopped leaking system after a couple of hours. Retired plumber
Date published: 2021-06-24
Rated 5 out of 5 by from FERNOX F4 Easy To Use Easy to use just read the instructions on the back.
Date published: 2021-06-21
Rated 5 out of 5 by from It really works - great peace of mind I was skeptical about this and had tried some Fernox external leak seal that just didn’t do the job. A radiator tail was weeping ever so slightly, perhaps one drop every few hours, but it would have been difficult to nip-up or bind with PTFE since it was soldered to a succession of end feed copper joints I didn’t fancy disturbing. I used a syringe and some tubing to extract around 500ml from the same towel radiator that had the leak and squeezed this stuff in, which is not too easy as it’s as viscous as 100W oil! I ran the system for a few hours and the leak was still apparent. However, within 48 hours it had dried up and not yet returned so this product gets 5 stars from me.
Date published: 2021-06-15
Rated 5 out of 5 by from Great product great price Best product for small leaks and keep pump running to ensure circulation around whole system and isolate/de-isolate radiators in turn over 24 hours for best results.
Date published: 2021-06-14
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