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Best Danfoss radiator thermostat

Updated: October 2026

You are replacing a Danfoss head, and the listing with 550 reviews or the one priced at £280 can look like the winner before you have checked what either product is. The best Danfoss radiator thermostat in this amazon.co.uk set depends on a spare-head job, not on review count and not on the highest price. Our [Danfoss thermostat comparison](/hub/thermostats/danfoss-thermostat) holds seven listings. Three of them are radiator heads. This page says who each head is for, and who should leave the Eco and the TP5000Si on the shelf. Figures are the GBP shelf prices and star lines in that comparison. We did not run a lab test. A qualifying purchase can earn us a commission at no extra cost to you.

You are replacing a Danfoss head, and the listing with 550 reviews or the one priced at £280 can look like the winner before you have checked what either product is.

Our top picks

Danfoss Danfoss Redia RA click

Best overall

Danfoss Danfoss Redia RA click
9.6/10about £16.99
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Danfoss Danfoss RAS-C2

Rank 2

Danfoss Danfoss RAS-C2
9.4/10about £30.18
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Danfoss Danfoss Eco 014G1115

Alternative

Danfoss Danfoss Eco 014G1115
7.6/10about £33.95
View offer
On this page
  1. 1.The criterion
  2. 2.Redia and RAS-C2
  3. 3.Why the Eco is not the pick
  4. 4.The £280 listing

The criterion

Best value here means the lowest price that still matches a Danfoss RA click valve and has a large UK review count behind an easy swap. That is the Redia. Top pick, among the mechanical heads, means the RAS-C2, because UK reviews describe it as an easier replacement than the older TRV, even though you pay more. Those labels are editorial, not a laboratory ranking. The Eco’s 550 reviews would win a count contest, and the TP5000Si’s 4.3 from 394 reviews would win a wall-stat contest. Neither contest is a spare head for a Danfoss RA valve. If you are not sure you need a head at all, the Danfoss thermostat buying guide separates heads from wall stats. If the head will not click on, read Danfoss RA or M30. A higher number on the dial is a setting question, on how to set a Danfoss thermostat, not a reason to change model.

Redia and RAS-C2

The Danfoss Redia, code 015G5120, is £16.99 with 4.8 from 235 reviews. The bullets describe a liquid sensor and a tool-free click onto a Danfoss RA valve. UK reviews describe the same sequence: set the head to 5, push it on, then set the number. The store record lists an RA-click connection and EN 215. That is the manufacturer’s claim, not a test we repeated. A 0.2 K band, an 18-minute response and up to 2% against traditional liquid heads are listing claims. An attribute block that mentions Wi-Fi, 230 V and a battery does not match a liquid head. The Danfoss RAS-C2, code 013G6040, is £30.18 with 4.7 from 73 reviews. UK reviews call it easier to fit and remove than an older TRV. The bullets claim a head-only change in under 30 seconds, with no leakage if the valve body stays in place. The Danfoss page describes an RA connection and a positive shut-off. Shut-off is that page’s claim, not a line in the amazon bullets. Choose the RAS-C2 when you want that sensor. Choose the Redia when the valve is already an RA click and you want the lower price. A cracked head on a click body does not need the Eco’s batteries or a £280 wall stat.
Danfoss Danfoss Redia RA click

Testsieger

Danfoss Danfoss Redia RA click
9.6/10about £16.99
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Why the Eco is not the pick

The Danfoss Eco, code 014G1115, is £33.95 and 3.8 from 550 reviews. The sample is the largest in the set, and the rating is why it is not the top pick for a spare head. UK reviews mention slow Bluetooth unless you are close, or you press the button or turn the ring, plus overshoot and an E6 fault. Danfoss support puts Bluetooth at about 10 m, so this is not a control for when you are away. The box includes adaptors for Danfoss bodies and, in the bullets, for M30 or M28. People use it to hold a bedroom cooler while the rest of the heating stays on. Buy it only if you want that schedule in the same room. If you only need a cracked head replaced, the Redia does that for £16.99 without batteries. Up to 30% energy savings, and 95% of radiators, are listing lines. We did not measure a bill.

The £280 listing

The Danfoss TP5000Si at £280 is not a radiator thermostat. The title says hardwired, not RF, and UK reviews describe a swap onto the original backplate. A 4.3 rating from 394 reviews does not mount this on the valve. The price is an outlier next to a TPOne at £32.49. Attribute lines that say Wi-Fi, and a model-name field that says TPOne, conflict with the title. If your job is a like-for-like wall-stat replacement and this price is acceptable, it belongs on the main page as a wall stat. If your job is a head, leave it. The TPOne, the RET2001 and the BasicPlus2 WT-D do not clamp onto a radiator neck either.

Common questions

Which head is the best value?
The Redia at £16.99, if the valve is a Danfoss RA click. It has 4.8 from 235 reviews, and UK texts describe a tool-free swap. It is a poor buy on an M30 thread, which the bullets do not claim to fit, and it has no programme. Compared with the RAS-C2 you save money and you give up the RAS-C2 sensor.
Why is the Eco not the top pick when it has 550 reviews?
Because the rating is 3.8, and the written UK reviews describe slow Bluetooth, overshoot and an E6 fault. Review count shows how many people bought it, not that the spare-head job is solved. It remains the head to consider when you want a schedule on one radiator and you will be in the room to use the app.
Is the RAS-C2 worth more than the Redia?
It is worth the extra if you want that sensor and the reviews that call the swap easier than an older TRV. The gap on these listings is £30.18 against £16.99. It is not worth it if you only need the cheapest RA click head, which is the Redia, or if your valve thread is unnamed. The Danfoss page mentions positive shut-off; the amazon bullets in this file do not, so do not pay the difference for a feature the listing did not state.
Does a high star rating on the TP5000Si make it the best Danfoss thermostat?
No, not for a radiator. It is a hardwired room thermostat at £280 on this listing, with 4.3 from 394 reviews. That can matter if you are replacing the same wall stat. It does not mount as a TRV head, and the title says it is not RF.
What should I skip if I only need a spare head?
Skip the Eco if you do not want batteries, Bluetooth or a schedule, and skip every wall stat, including the £280 TP5000Si, the TPOne, the RET2001 and the BasicPlus2. Between the two liquid heads, skip the RAS-C2 if the Redia’s RA click match and £16.99 are enough. Skip the Redia if the valve is not RA click.
Who should buy the Eco anyway?
Someone who wants one radiator on a daily pattern or a holiday setback, controlled from a phone in the same room, and who accepts 3.8 from 550 reviews. The adaptors are the practical reason, when the valve is not a plain RA click the Redia can use. If the pin does not spring back, fit nothing until that is fixed.

Related pages

Heating schedule mistakes

Danfoss thermostat

Danfoss thermostat buying guide: head, Eco or wall

How to set a Danfoss thermostat: dial and wall stat

Danfoss RA or M30: which radiator head will mount

Room thermostat or TRV and the England boiler pattern

Sources

Public UK sources for Approved Document L, BS EN 215, Danfoss product data, and Part P. Listings are the amazon.co.uk captures for these seven ASINs, not a live reload on 17 October 2026. Prices on amazon.co.uk move.

  1. BEAMA Part L 2022 heating controls (retrieved 17 October 2026)
  2. Danfoss GB, Part L (retrieved 17 October 2026)
  3. BSI, BS EN 215:2019 (retrieved 17 October 2026)
  4. Danfoss Eco data sheet (retrieved 17 October 2026)
  5. Danfoss Eco support (retrieved 17 October 2026)
  6. Danfoss RAS-C2 013G6040 (retrieved 17 October 2026)
  7. Danfoss Redia 015G5120 (retrieved 17 October 2026)
  8. IET Part P FAQ (retrieved 17 October 2026)