Danfoss RA or M30
Updated: October 2026
You are at the radiator with the old head in your hand, and the new Danfoss box does not say whether it will click or whether it needs a threaded ring. Danfoss RA or M30 is that choice. An RA click head will not become an M30 head if you push harder, and an M30 nut will not click onto an RA body. This page matches the mount you can see to the listings in our [Danfoss thermostat comparison](/hub/thermostats/danfoss-thermostat). It is not a dial guide and it is not a Building Regulations page. Once the thread is known, the [buying guide](/hub/thermostats/danfoss-thermostat/sub/danfoss-thermostat-buying-guide) picks the product. Prices below are GBP on amazon.co.uk. We did not fit these heads in a lab. A qualifying purchase can earn a commission at no extra cost to you.
You are at the radiator with the old head in your hand, and the new Danfoss box does not say whether it will click or whether it needs a threaded ring. Danfoss RA or M30 is that choice.
You are at the radiator with the old head in your hand, and the new Danfoss box does not say whether it will click or whether it needs a threaded ring. Danfoss RA or M30 is that choice. An RA click head will not become an M30 head if you push harder, and an M30 nut will not click onto an RA body. This page matches the mount you can see to the listings in our Danfoss thermostat comparison. It is not a dial guide and it is not a Building Regulations page. Once the thread is known, the buying guide picks the product. Prices below are GBP on amazon.co.uk. We did not fit these heads in a lab. A qualifying purchase can earn a commission at no extra cost to you.
Our top picks
| Badge | Product | Connection | Fitting | Power | Note | Price | Offer |
|---|---|---|---|---|---|---|---|
| Best overall |  Danfoss Danfoss Redia RA click | Danfoss RA | RA click, no tools | None in the bullets | 9.6 | about £16.99 | View offer |
 Danfoss Danfoss RAS-C2 | Danfoss RA; M30 not named | Head swap, under 30 seconds claimed | None in the bullets | 9.4 | about £30.18 | View offer | |
| Alternative |  Danfoss Danfoss Eco 014G1115 | Danfoss bodies plus M30 or M28 adapters | Adapters for Danfoss, M30 or M28 | 2 AA | 7.6 | about £33.95 | View offer |
Two mounts
Look at the valve neck, not at the brand on the old plastic. An RA click body takes a head that pushes on. UK reviews of the Redia describe setting the head to 5, pushing it on, then turning it down. There is no threaded nut doing the clamping. M30x1.5 is the threaded metal ring many UK radiators use. A Drayton Wiser adaptor note from Schneider describes M30x1.5 as the common UK thread and Danfoss RA as the less common one. The two mounts are not the same part. A React datasheet lists RA click and M30x1.5 under different references. React is not one of the seven listings here, so do not order a React code from this paragraph. If the old head is seized on, do not guess. A stuck pin or a weeping nut is where a heating engineer takes over. A photo of the bare neck saves a return that a star rating cannot.
Which listing matches
The Redia, code 015G5120, at £16.99, is RA click in the bullets and on the Danfoss store record. The raw listing does not say it fits M30. UK reviews praise the click-on swap. They are not an M30 test. If your valve has a threaded ring, this is the wrong ASIN, however attractive 4.8 from 235 reviews looks. The best value in the wider comparison only holds when the mount matches. The RAS-C2, code 013G6040, at £30.18, is described as a head swap with a built-in sensor. The amazon raw file does not name M30. The Danfoss page for 013G6040 says an RA connection. Buy it as an RA head, not as a universal spare. Positive shut-off is on that Danfoss page, not in the amazon bullets. UK reviews that call it easier than an older TRV are still RA-head comments, not a thread conversion. The Eco, code 014G1115, at £33.95, is the listing whose bullets claim adaptors for Danfoss bodies and for M30 or M28. The Danfoss store record for this code lists adaptors for RA, RAV, RAVL and M30. That is why it is the only head in this set to open when the neck is not a plain RA click. It is still a Bluetooth head with a 3.8 rating from 550 reviews, not a free pass. The best Danfoss radiator thermostat page says when that compromise is worth it. After it is on, the number you set is covered in how to set a Danfoss thermostat.
The 95% line
The Eco listing claims adaptors for 95% of radiators. That percentage is a marketing line. This comparison did not survey UK housing stock, and a Danfoss RA body plus an M30 body in the same house is already enough to show why one head shape fails. If the adaptor in the Eco box does not match the neck you can see, the claim has not helped you. Do not file the thread off, and do not wrap tape around a click collet to make it feel tight. Picture a terrace where the front room still has the original Danfoss click valve and a later extension radiator was fitted with a standard M30 body. The Redia belongs on the first radiator only. The Eco’s adaptor pack is the listing that even claims to cover the second, and only if the piece in the box actually matches. RAV and RAVL appear on the Eco store record as further Danfoss patterns. They are not a reason to force the Redia collet onto a valve that looks different. The wall stats in the same comparison never solve this. The TPOne, the RET2001, the TP5000Si at £280 and the BasicPlus2 are not radiator heads. A high review count on the TP5000Si does not put an RA collet or an M30 nut in the box.
If it will not mount
Stop before the plastic creaks. An RA head that will not push home is either on the wrong body, or the pin is not free. Press the pin with a firm finger. It should travel in and spring back. A UK Eco review treats that check as part of fitting. If the pin stays down, a new head will not open the radiator, and forcing the collet can damage the valve. If water is present, do not loosen the nut to have a look. Draining is not described here because it is a heating engineer’s job once the system has to be opened. A Danfoss nut on an older valve is not the same as an RA click, even when the metal says Danfoss. The Redia sequence of setting the head to 5 and pushing is for a click head. It will not convert a threaded union. Match what you can see, order that listing, and only then set the number. RAS-CK is a Danfoss pattern you may see in older catalogues. It is not an ASIN in this comparison, so do not treat a forum mention of it as one of these seven products.
Common questions
How do I tell RA click from M30?
RA click pushes on after you set the head to the fitting position. UK Redia reviews describe set to 5, push, then turn down. M30x1.5 uses a threaded ring that a nut clamps. If you can see a screw thread on the valve neck, do not order a click-only head. If you can see a smooth Danfoss click collar, do not expect an M30 nut to lock onto it.
Will the Redia fit an M30 valve?
The bullets and the Danfoss store record for 015G5120 specify RA click. They do not say M30. Pushing harder will not cut a thread. At £16.99 and 4.8 from 235 reviews it is the best value when the valve really is RA click, and the wrong product when it is not.
Does the RAS-C2 listing name M30?
No. The raw amazon file does not name M30. The Danfoss page for 013G6040 describes an RA connection. Treat it as an RA head at £30.18, and use the Eco only if you need the adaptor claim and you accept the Eco’s review themes.
Which product in this set includes adaptors?
The Eco, code 014G1115. The bullets claim adaptors for Danfoss bodies and for M30 or M28. The store record also lists RA, RAV, RAVL and M30. The Redia and the RAS-C2 do not make that claim. The wall thermostats are irrelevant to the neck of the valve.
Is 95% of radiators a measured figure?
It is a listing claim on the Eco. We did not measure it. An adaptor that does not match the valve in front of you is a mismatch, whatever the percentage says. The rating of 3.8 from 550 reviews is a separate reason to read the faults before you rely on the box to cover every radiator in a UK terrace.
What if the old head is a Danfoss nut rather than a click?
Then the Redia click sequence does not apply. Danfoss has used more than one mount, which is why RA and M30 appear as separate codes on a React datasheet even though React is not in this set. Identify the thread, or ask an engineer if the head will not come off. Do not assume every Danfoss head fits every Danfoss valve.
Can I force a click head onto the wrong body?
No. If it will not seat, it is the wrong mount or the pin is seized. Forcing it risks the collet and will not make an RA head into an M30 head. Check that the pin springs back. If it does not, or the valve weeps, stop and call a heating engineer rather than draining the system from a guide.
Related pages
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.
- BEAMA Part L 2022 heating controls (retrieved 17 October 2026)
- Danfoss GB, Part L (retrieved 17 October 2026)
- BSI, BS EN 215:2019 (retrieved 17 October 2026)
- Danfoss Eco data sheet (retrieved 17 October 2026)
- Danfoss Eco support (retrieved 17 October 2026)
- Danfoss RAS-C2 013G6040 (retrieved 17 October 2026)
- Danfoss Redia 015G5120 (retrieved 17 October 2026)
- IET Part P FAQ (retrieved 17 October 2026)