The best heimeier thermostats, compared.
Top pick: Heimeier K, Danfoss RAVL – Liquid-filled K head for a Danfoss RAVL collar, 6–28 °C marked 1–5, and 4.5 from 285 reviews, the largest review file in this set. Best value: Heimeier K-Eco 6071-43.500 – About £19.00 for a named M30×1.5 K-Eco with frost protection and an Eco mark at 20 °C. The listing has no star line. Updated October 2026.
A Heimeier thermostat in a UK home is a thermostatic radiator valve head, and sometimes a valve body, that limits how much hot water enters one radiator as the room air warms. On amazon.co.uk the usual job is a cracked dial or a match to a or body, not a Wi-Fi room thermostat. A collar and a valve from 1987 need a direct-fit head. A 15 mm pipe size is not the head thread. Lines on the attribute grid that say Wi-Fi, or 230 V are not what the titles describe. How to read the thread, the head, and the scale is in the [Heimeier thermostat buying guide](/hub/thermostats/heimeier-thermostat/sub/heimeier-thermostat-buying-guide).
A Heimeier thermostat in a UK home is a thermostatic radiator valve head, and sometimes a valve body, that limits how much hot water enters one radiator as the room air warms.
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Personal buying guide
Question 1 of 2
Which connection is on the valve?
Across 285 amazon.co.uk reviews, this liquid-filled K head is the one buyers use on a Danfoss RAVL collar, with a 6–28 °C scale marked 1–5 and frost protection. Reviewers say it fits a RAVL-style valve without an adapter and turns more easily than a stiff Danfoss head. Several say a non-specialist could swap it, and that the radiator eases off when the room is warm. The brand field on the listing is Sanitop-Wingenroth, while the item type and the box line both say a Heimeier thermostatic head K, model 27135 6. Plastic claw teeth are the durability complaint that comes back: reviewers fear they snap, and one describes broken teeth on older heads of this type. One unit did not open or close the radiator and went back at the buyer’s cost. The head also sticks out from the radiator, and the attribute grid adds a battery, 230 V, wiring, and BACnet that the bullets do not describe.
Pros
Cons
Best for: A Danfoss RAVL valve when you want a Heimeier-style K head at about £22.75 and can see the collar before you order.
Less suitable: A plain M30×1.5 body, a Vaillant direct valve, or anyone who needs a child lock or a timed programme.
Specifications
Common questions
Which valve does this head say it fits?
The title and bullets say a Danfoss RAVL connection, with a liquid-filled sensor and a 6–28 °C scale.
Is it a programmable thermostat?
The page asks that question and does not answer it. The bullets describe marks 1–5 and frost protection, not a timed programme.
Does the listing include a child lock?
A customer question asks about a child lock. No answer is printed on the listing.
The 9712-00.500 is a thermostatic head with a direct connection for Vaillant, at about £29.67 and a stated weight of 100 g. The rating line is 4.2 out of 5 from 4 reviews, and the one printed UK review, dated 23 August 2026, says it fitted Vaillant valves and replaced a faulty valve. That review calls the quality good and does not describe a defect. A question about other brands is unanswered, so the title’s Vaillant connection is as far as the page goes. The material line lists both metal and stainless steel. The attribute grid also says programmable, Wi-Fi, a battery, and 230 V, which the title and the box line do not.
Pros
Cons
Best for: A Vaillant valve that needs article 9712-00.500, if that direct connection matches the body you have.
Less suitable: An M30×1.5 Heimeier body, a Danfoss RAVL collar, or any other brand until the connection is confirmed.
Specifications
Common questions
Which valves does the title name?
The title says a direct connection for Vaillant. One UK review says it fitted Vaillant valves and replaced a faulty valve.
Will it fit other brands?
The page asks that question. No answer is printed beyond the Vaillant title and that one review.
How many review texts are on the listing?
The rating line says 4.2 from 4 reviews. One review body is printed.
The HEIMFF listing is a white thermostatic head, included as a K 7000, at about £14.51, the lowest price in this set. The rating line is 3.5 out of 5 from 4 reviews, and the three short UK texts on the listing all say it was easy to fit and that it worked afterwards. None of those reviews names a thread, a seized pin, or a fault. No connection size is printed, so the page does not tell you whether the nut is M30×1.5 or a Danfoss pattern. The manufacturer line says Conmetall. The attribute grid adds remote, RF, a battery, and 230 V that the included-components line does not support, and a question about a digital display is unanswered while the grid says analogue.
Pros
Cons
Best for: A white K-style head when you already know the valve matches and the about £14.51 price is why you are looking.
Less suitable: A first order when the thread is still unknown, or anyone reading the grid as a smart or RF head.
Specifications
Common questions
Does the listing say it has a digital display?
A customer question asks. The attribute grid says the display type is analogue, and no review describes a screen.
Is a thread size printed?
No connection size is printed. Included components say a thermostatic head K 7000 in white.
What do the four reviews say?
Three short UK reviews are on the listing. They say it was easy to fit and that it works. They do not describe a fault.
The K-Eco 6071-43.500 is a liquid-filled head for an M30×1.5 insert, sold with a mounting bracket at about £19.00 and a stated weight of 130 g. The Amazon bullets print a short scale: minus is 16 °C, Eco is 20 °C, and plus is 24 °C, with frost protection. That is a narrower set of marks than the 6–28 °C, 1–5 scale on the RAVL listing in this comparison. The listing has no customer-review line and no review text, so there is no buyer account of how the dial feels or whether the bracket lines up. The attribute grid also says Zigbee, a battery, 230 V, and ceiling mount, none of which the bullets confirm. You are buying a named M30 article, and you are doing it without a star line to lean on.
Pros
Cons
Best for: An M30×1.5 insert when a short Eco scale is what you want and you will accept a listing with no reviews.
Less suitable: A Danfoss RAVL collar, a Vaillant direct valve, or anyone who needs marks 1–5 and a review file.
Specifications
Common questions
What temperature scale is printed?
The bullets say minus is 16 °C, Eco is 20 °C, and plus is 24 °C, with frost protection.
Which thread does the listing state?
The bullets say M30×1.5.
Are there amazon.co.uk reviews on the listing?
No customer-review line and no review text are on the listing.
The 2805-00.500 is a remote-adjuster head with a 5 m capillary listed in the box, at about £64.15. Frost protection is named in special features, the grid calls the display analogue, and the materials are metal and plastic at 136 g. The listing has no customer-review line and no review text, so nobody on the page describes how the tube routes or where the adjuster ends up. The connection is not stated, and the listing asks whether it fits any radiator without giving an answer. Instructions are asked about and not confirmed. The attribute grid also says Wi-Fi, BACnet, hardwire, and 230 V, which the title and the included-components line do not support.
Pros
Cons
Best for: A radiator you cannot reach, when you have already measured a run that needs about 5 m and you know the head thread.
Less suitable: An open radiator in free air, or a first head while the connection is still unknown.
Specifications
Common questions
How long is the capillary?
The title and the included-components line both say 5 m.
Does the listing say it fits every radiator?
The page asks that question. No answer is printed.
Are instructions listed?
The page asks whether instructions are included. No answer is printed.
The 6402-00.500 is a metal thermostat head at about £58.92 and 280 g, with a heat-conducting base and a hairspring, and the title sells it as a 2 m version. No thread size is printed, and the included-components line says only 1. The listing has no customer-review line and no review text. Questions about whether it fits any radiator, and whether instructions are in the box, are unanswered. The attribute grid adds Alexa, Google Assistant, Zigbee, a touchscreen, and 230 V that the title does not support. The 2 m figure and the heat-conducting base are the only reasons to pay this, and only after you have matched the thread yourself.
Pros
Cons
Best for: A covered radiator where you have measured a run of about 2 m and you already know the thread.
Less suitable: A standard open radiator, or anyone who read the attribute grid as a voice-controlled thermostat.
Specifications
Common questions
What length is in the title?
The title says 2 m, with a heat-conducting base and a hairspring.
Which thread is printed?
No thread size is printed on the listing.
Are there reviews on the listing?
No customer-review line and no review text are on the listing.
The V-exact II 3710-02.000 is an axial valve body, DN 15 (1/2 inch), at about £19.39, not a dial you unscrew and replace. The bullet says nickel-plated gunmetal, while the material line says brass and nickel, and the stated weight is 100 g. Included components say nothing special is included, so a thermostatic head is a separate purchase. The listing has no customer-review line and no review text. The head thread is not stated, which matters if you already own an M30 head and expected this body to name it. The attribute grid also says Wi-Fi, mains, and 230 V on a valve base. At this price you are buying the body only.
Pros
Cons
Best for: A 1/2 inch axial replacement when you already have a matching head and you are changing the body, not the dial.
Less suitable: Anyone who wanted a sensor head tonight, or a straight or angle body this listing does not describe.
Specifications
Common questions
Is this the sensor head?
The item type is valve base. The bullet describes a V-exact II axial body, DN 15, nickel-plated gunmetal.
Is a head included?
Included components say nothing special is included.
What size is printed?
The title and bullet say 1/2 inch, DN 15, axial.
The 2001-02.300 is a thermostat top with cam identification for DN 10 and DN 15, at about £15.60 and 90 g, not a numbered dial. The material line says brass, the colour is gold, and the finish line says classic. Included components say a thermostat top. The listing has no customer-review line, and a question about use on radiators is unanswered. The attribute grid says manual control and, beside that, a touchscreen, a battery, and 230 V. Special features name DN 10 and DN 15, and they do not state a head thread. You would fit this as an insert on those sizes, and you would still need a head if the job was a new temperature dial.
Pros
Cons
Best for: A DN 10 or DN 15 valve that needs this thermostat top, when you already know the insert pattern.
Less suitable: Anyone shopping for a K head with marks 1–5, or a remote adjuster.
Specifications
Common questions
What is in the box?
Included components say a thermostat top. The title adds cam identification and article 2001-02.300.
Which sizes are named?
The title and special features say DN 10 and DN 15.
What material is printed?
The material line says brass. Colour is gold and the finish line says classic.
Shelf prices, stars, and review counts are the amazon.co.uk figures stored for these eight listings on 15 October 2026. They are not a live reload. The number on each card is the stored 0–100 figure for this set divided by 10. A listing with no star line is stored at 0 and shown at 5.0, so it stays below every reviewed listing and is not treated as a failed test. There is no laboratory ranking and no measured gas saving for these parcels. The weights below are the buying checks used to read the set.
Connection
30%Read the old head: M30×1.5, Danfoss RA, RAV, or RAVL, or Vaillant. A 15 mm pipe size is not the head thread. Danfoss RAVL and Vaillant from 1987 need a direct-fit head.
Head or body
20%If the pin springs and the radiator heats with the head off, buy a head. If the pin is solid or the gland weeps, you need the brass body and a drain-down.
Sensor location
20%Open radiator, horizontal valve: built-in sensor. Curtains, a cabinet, or a tight vertical niche: a remote sensor or remote adjuster. Measure 2 m against 5 m before you pay for a capillary.
Scale
15%A standard K head uses numbers 1–5, with 3 about 20 °C on IMI’s K datasheet. K-Eco 6071-43.500 is sold with a short scale: minus 16 °C, Eco 20 °C, plus 24 °C, and frost protection.
Evidence and price
15%Prefer an article number you can match to IMI. Stars and review volume come from the amazon.co.uk line. Do not treat Amazon Wi-Fi, 230 V, or Alexa lines as real on these mechanical heads. Captured prices run from about £14.51 to about £64.15.
Start with the connection on the valve, then whether you need a head or a body, then whether the sensor can see the room. A star line does not tell you those three. The eight listings below are amazon.co.uk pages, with prices and review counts stored on 15 October 2026, not a live reload. These are mechanical parts. A Wi-Fi or Alexa line on the attribute grid is not a feature the title describes.
A Heimeier thermostat, as UK shoppers search for it, is a thermostatic radiator valve head, sometimes sold with or as a valve body, that limits hot water into one radiator as the room air warms. You choose it when a dial has cracked or when the body on the wall is Danfoss or Vaillant, not when you want a Wi-Fi room thermostat. Quality starts with the right thread. IMI’s standard is M30×1.5. Danfoss RAVL and Vaillant from 1987 need a direct-fit head. A 15 mm pipe size is not the head thread.
IMI’s standard nut is M30×1.5. A Danfoss RAVL collar needs the direct-fit head, the liquid-filled K listing at about £22.75. A 15 mm pipe size does not tell you which nut you have. Read the old head before you order, and return the part if the thread is wrong.
If the pin springs and the radiator heats with the head off, buy a head. The V-exact II axial body and the 2001-02.300 thermostat top are not numbered dials, and the axial body does not include a head. A solid pin or a weeping gland is the body job, and that needs a drain-down.
A built-in head in a casing or behind curtains reads the wrong air even when the thread is right. The 2 m head and the 5 m remote adjuster are the listings for that job, and only after you have measured the run and confirmed the connection. Do not cut the capillary.
Match the connection before the price. M30×1.5 is IMI’s standard. Danfoss RAVL is the direct K head in this set, about £22.75, with 4.5 from 285 reviews. Vaillant from 1987 is article 9712-00.500, about £29.67. The HEIMFF head is the lowest price, about £14.51, and it does not print a thread, so it is a poor first order. If the pin is free, you need a head. If the pin is solid or the gland weeps, you need a body.
Number 3 on a standard K head is about 20 °C on IMI’s K datasheet. The K-Eco scale is shorter: 16 °C, Eco 20 °C, and 24 °C. Frost protection is printed on those two heads and named on the 5 m adjuster. Leaving the dial on frost all summer is how pins stick. A covered radiator needs a measured capillary, 2 m or 5 m in this set, at about £58.92 and about £64.15. Both of those listings, and several of the cheaper ones, carry attribute lines for Wi-Fi, Alexa, Zigbee, or 230 V. The titles do not.
Three typical situations, each with a recommendation from this comparison.
You are swapping one head and the collar is Danfoss RAVL. The liquid-filled K head at about £22.75 is the top pick, with 4.5 from 285 reviews and a 6–28 °C scale marked 1–5. The brand line says Sanitop-Wingenroth. Check the collar before you order.
The valve takes M30×1.5 and you want the Eco marks rather than numbers 1–5. The Heimeier K-Eco 6071-43.500 is the best value at about £19.00, with frost protection and a mounting bracket. The listing has no star line.
The sensor must see the room. The Heimeier 2805-00.500 is a remote adjuster with a 5 m capillary at about £64.15, and no review line. Measure the run, and do not buy it if the head already sits in free air. The connection size is not printed.
The top pick is the liquid-filled K head for a Danfoss RAVL connection, at about £22.75, with 4.5 from 285 reviews, a 6–28 °C scale marked 1–5, and frost protection. Reviewers describe a fit without an adapter. The brand line says Sanitop-Wingenroth, and plastic grip teeth are the durability complaint. The best value is the Heimeier K-Eco 6071-43.500, at about £19.00, for an M30×1.5 insert and a short scale of 16 °C, Eco 20 °C, and 24 °C. That listing has no star line. A Vaillant direct head, a capillary, a valve body, and a thermostat top are different jobs. The card score is the stored listing figure, not a laboratory test.
Heimeier K, Danfoss RAVL
Liquid-filled K head for a Danfoss RAVL collar, 6–28 °C marked 1–5, and 4.5 from 285 reviews, the largest review file in this set.
Heimeier K-Eco 6071-43.500
About £19.00 for a named M30×1.5 K-Eco with frost protection and an Eco mark at 20 °C. The listing has no star line.
Editorial
Peter F. is the editor for DIY & tools at productscompared.co.uk. Comparisons in this category are checked against amazon.co.uk listings, review evidence and public UK sources.
Guides on what to look for, how to use a product, and common mistakes.
Public sources are IMI head data, BS EN 215:2019, Approved Document L, the BEAMA installer factsheet, and Energy Saving Trust. Listings are the amazon.co.uk captures for these eight ASINs on 15 October 2026, not a live reload. Prices on amazon.co.uk move. A KEYMARK line on an IMI datasheet is not a mark on an ASIN that does not print it.
This page contains affiliate links to amazon.co.uk. If you buy through them, we may earn a commission at no extra cost to you. Prices, stars, and review counts come from those listings. We did not run a laboratory test. The scores rank a listing inside this set only.
