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Honeywell L641A Cylinder Stat

Product Code: 40051
Honeywell L641A Cylinder Stat
Product Code: 40051
Bi-metallic sensor. Surface-mounted. Control for boilers and wet central heating. Conforms to 89/336/EEC and 73/23/EEC. EN 60730.


  • Suitable for Uninsulated & Foam-Lagged Cylinders
  • Fixing Strap Included
  • Double Insulated
  • 1 Year Guarantee
  • Suitable for Uninsulated & Foam-Lagged Cylinders
  • Fixing Strap Included
  • Double Insulated


Switch/contact rating: 4A resistive. 2A inductive. SPDT. Temperature range: 40°-80°C. H x W x D: 85 x 45 x 55mm.
€27.95 Incl. 20% VAT
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Additional Information
Technical Specification
  • Brand : Honeywell
  • Manufacturing Standards : Building Regs Compliant, Conforms to 89/336/EEC and 73/23/EEC
  • Product Height : 85 mm
  • Product Type : Cylinder Stat
  • Zoning Level : One
  • Insulation Type : Double-Insulated
  • Central Heating Control Type : Thermostats
  • Model No : L641A
  • Product Width : 45 mm
  • Temperature Range : 40 to 80 °C
  • Product Depth : 55 mm
  • Pack Size : 1
  • Suitable System : Suitable for Uninsulated / Foam-Lagged Cylinders
  • Compatible Boiler Type : All Boilers
  • Manufacturer Guarantee : 1 Year Guarantee
  • Pieces in Pack/Case : 1
  • Mount Type : Surface-Mounted
  • Sensor Type : Bi-Metallic Sensor
Product Contents
Delivery & Returns


Standard delivery: €15

Free delivery on all orders over €70.00

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Hopefully you won't need to return an item, however, if you do, it is our aim to make this as simple as possible. By following the guidance below you can help us to help you when a product is not what you expected, or is faulty. Your statutory rights are not affected by this guidance.


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Honeywell L641A Cylinder Stat is rated 4.5 out of 5 by 16.
Rated 5 out of 5 by from Simple, reliable and robust. Damaged the previous 10 year old thermostat by mistake. This is a direct replacement, simple to fit straight out of the box.
Date published: 2017-01-15
Rated 5 out of 5 by from Perfect replacement Bought this product to replace an older faulty one. Simple to install the new unit to the existing wiring (3 wires) and now all working as it should do!
Date published: 2016-12-14
Rated 5 out of 5 by from Seems v good Replaced a twenty-year old Potterton t.stat. Quick and easy. three wires to connect. Needed no earth. Looks robust plastic and metal.. Well-designed terminals and cable clamp. I checked the set temp with an IR thermometer and it was controlling to within a degree or so of the set temp.
Date published: 2016-09-22
Rated 4 out of 5 by from Honeywell Cylinder Stat. I have always used Honeywell stuff for central heating system controls and the cylinder stat is an easy wire, easy fit unit that I know will give good reliable service to my customer which is all you want for a business life free from call- backs.
Date published: 2016-09-09
Rated 5 out of 5 by from Quality item This is a like for like replacement purchase. I fitted the original one thirty years ago need I say more!
Date published: 2016-06-27
Rated 5 out of 5 by from Easy fix thermostat Could not be simpler to fit comes with instruction which are so easy to follow just 2wires to connect set temperature on dial job done
Date published: 2016-03-07
Rated 4 out of 5 by from Just works Replaced like for like unit, easy job took 10mins and works just fine.
Date published: 2016-01-30
Rated 5 out of 5 by from Honeywell L641A Cylinder Stat Used to replace older Honeywell Stat, Easy to replace just fit ex cables to new stat, fit the new strap in place and switch on. Works well.
Date published: 2015-09-03
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