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🔥 Take control of your hot water like a pro—effortless, secure, and smart!
The Honeywell L641A1039 Cylinder Thermostat is a compact, surface-mounted device designed for precise manual temperature control of domestic hot water cylinders. Featuring a snap action SPDT micro switch, tamperproof settings, and easily accessible wiring terminals, it enables quick installation and reliable operation of heating pumps or zone valves. Trusted for its durability and efficiency, this thermostat offers a modern solution to optimize your home’s hot water system while saving energy and installation costs.
| ASIN | B003DTIWGO |
| Backlight | No |
| Best Sellers Rank | 45,603 in DIY & Tools ( See Top 100 in DIY & Tools ) 59 in Thermostats 4,950 in Electrical |
| Brand Name | Honeywell |
| Colour | White |
| Connectivity Protocol | Wi-Fi |
| Connectivity Technology | Wired and Wi-Fi |
| Control Method | Touch |
| Control Type | Button Control |
| Controller Type | knob,manual |
| Customer Reviews | 4.6 4.6 out of 5 stars (748) |
| Display Type | manual |
| Finish Type | Mixed |
| Global Trade Identification Number | 05023220200093 |
| Included Components | Cylinder Stat |
| Item Type Name | Cylinder Stat |
| Manufacturer | Honeywell |
| Material Type | Plastic |
| Model Name | Cylinder Stat |
| Model Number | L641A1039 |
| Mounting Type | Surface Mount |
| Number of Batteries | 2 AA batteries required. |
| Power Source | AC |
| Product Style | Modern |
| Special Features | Manual Setting Knob, Tamperproof Temperature Setting |
| Specific Uses For Product | Indoor use only |
| Temperature Control Type | Manual |
| Unit Count | 1.0 count |
| Voltage | 230 Volts |
M**G
Honeywell cylinder thermostat.
Easy to fit and nice and compact unit to replace old type thermostat. Works well and temperature dial easy to adjust.
R**D
Easy as 1-2-3 and cheaper here than local stores
Fitted in place of British Gas CS1 (which is the same as a Drayton RTS3) which was asking for hot water constantly and wouldn't switch off. Normally we only have the water programmed on for an hour a day but one day left it on by mistake and I noticed the water was insanely hot / the boiler was heating it constantly! The existing hole in my tank's insulation was wide enough although I did scrape a little extra clearance with the end of the screwdriver. I also used the existing wire band as this saved faffing around altering the one included here. After isolating the electrics, I opened up both 'stats, took a photo of the wiring in the old one and simply connected the wires to the same terminals in this unit. It was literally as easy as 1-2-3! If you can wire a plug, you can wire one of these up. The price here - approx £15 including delivery - was half the price of Screwfix / Toolstation and judging by the reviews this item is more reliable than my previous 'stat (although I suspect the old one was 10+ years old). All in all it's an easy fix. My wife tried to convince me to call a plumber. I saved a call-out, an 'hour's' labour (it took me 15 mins!) charge and no doubt a significant mark up on the item (which they may have paid £30 + for!) - so around £60 in total savings! I'll pocket the £60 to spend on more interesting things. Easy as 1-2-3.
A**R
Thermostat
Great value. Easily fitted to tank
K**R
Replacement for a very old one
Works well
"**"
Excellent customer support
This is an excellent product and the support is great, it arrived on time. Recommended
I**R
Honeywell stat - does the job
Replaced a 30 year old honeywell tank stat 140 - 180 F which finally gave up the ghost, hope this one lasts as long. Easy to fit and has far closer temp control than the old one, always happy with honeywell equipment, reliable and well made.
J**.
Simple mechanism
I bought this to replace a suspect existing tank thermostat. The unit comprises of a bimetal strip mechanically connected to a microswitch with a normally on and normally off set of contacts. The unit is held to the hot water tank by a stretchy "curtain" wire which is a little tricky to attach as you need three hands. This unit is meant for contact to a copper cylinder as I assume attaching it to fibreglass or pre insulated type would not work properly.
K**G
Good price
A good price and works well.
Trustpilot
1 month ago
3 days ago