Before you can fit your Radiator Valve ORIGINAL, you need to take off the existing valve head that sits on your radiator. This guide walks you through it, step by step.
Good to know before you start
You are only removing the control head — the part you turn to set the temperature. The valve body stays screwed into the radiator, and no water will escape. Your heating system stays sealed the entire time.An adjustable radiator valve has two parts. The valve body is the brass fitting fixed to the radiator and pipework, with a spring-loaded pin that controls the hot water. On top sits the valve head (the knob or thermostatic head) that pushes this pin as you turn it.
Your Smart Radiator Thermostat replaces the old head, doing the same job automatically. You just unscrew the head to expose the valve body's connection ring underneath.
Take a moment to identify your valve first
Valve heads attach in different ways depending on the brand — some clip on, some use a threaded ring nut, and some are held by a small grub screw. Look closely at where your head meets the valve body so you know which of the methods below applies to you.
Step-by-step: removing the old head
Turn the valve fully open
Rotate the existing head anticlockwise all the way to its highest number (or the open/sun symbol). This releases the tension on the internal pin and makes the head far easier to detach.
Find how your head is fixed on
Look at the joint between the head and the radiator. It will be one of these:
Threaded ring nut — a knurled collar or nut where the head meets the body.
Grub screw — a small screw or plastic clip on the side of the head.
Push/clip fit — no visible nut; the head simply clips over the body.
Loosen the fixing
For a ring nut (A): turn the nut anticlockwise. Start by hand; if it won't budge, wrap a cloth around it and use an adjustable spanner gently. Only loosen the nut that holds the head — leave the larger nut that joins the body to the radiator alone.
For a grub screw or clip (B): loosen the screw a few turns (you usually don't need to remove it completely) or release the clip.
For a push fit (C): no tools needed — move straight to the next step.
Lift the head straight off
With the fixing loose, pull the head straight up and away from the valve body. You may feel light resistance from the internal pin — that's normal. Set the old head aside somewhere safe.
Keep the old parts
Store the head, nut and any adapter together in a labelled bag. If you ever move home or return the smart thermostat, you'll want to put the original back.
Check the exposed valve body
You should now see the valve body with a small metal pin in the centre and a threaded connection ring around it. Give the ring a quick wipe with your cloth to clear any dust or limestone. This threaded ring is exactly where your Smart Radiator Thermostat (or its adapter) will screw on.
Confirm the pin moves freely
Gently press the central pin with a fingertip and let it spring back. It should move smoothly. If it feels stuck — common on older radiators that haven't been touched in a while — see the troubleshooting section below before fitting the new thermostat.
⚠️ Important — do not touch these
Never loosen the large nut that connects the valve body to the radiator or the pipe, and don't try to unscrew the body itself. Those joints hold back the water in your system. Removing them is a plumbing job and could flood the room. You only ever need to remove the head.
The ring nut is stuck and won't turn
Older nuts can seize over time. Wrap a cloth around it for grip, hold the valve body steady with one hand, and apply steady pressure with an adjustable spanner anticlockwise. Avoid sudden force. If it still won't move, stop and contact a heating professional rather than risk damaging the valve.
The centre pin is stuck down and won't spring back
This happens when a pin has been held closed for a long time. Grip the pin with pliers padded by a cloth and ease it out with gentle, repeated pulls — never yank it. Once it moves freely again, your valve ORIGINAL will be able to control it properly.
Water dripped out when I removed the head
This should not happen when you only remove the head. If you see water, you have likely loosened the body-to-radiator joint instead. Retighten it immediately and contact a qualified heating engineer before continuing.
Installing the Radiator Valve ORIGINAL
Now that the old head is off and the valve body is exposed, you're ready to mount your Radiator Valve ORIGINAL. This part takes just a few minutes and needs no tools.
Before you begin
Keep the small parts bag, the adapters and the adapter identification cards from the box within reach. If you removed your old head more than a few minutes ago, quickly re-check that the central pin on the valve body still springs back freely (see the previous section).
Step 1 — Identify your valve body
The Thermostatic Valve ORIGINAL uses a standard M30 Ă— 1.5 thread and ships with 6 adapters in the box, covering most radiator valve body types on the market.
If your valve body already has an M30 × 1.5 thread, screw the Valve ORIGINAL directly onto it — no adapter required. This covers the majority of radiator valves in Europe, so there's a good chance you can skip straight to Step 3.
On the other hand, the quickest way to know what you're dealing with is the adapter identification cards included in the box:
if your valve body has threads, the adapter identification is the plastic one with diameters.
If your valve body doesn’t have threads, you can use the adapter identification with the different silhouettes.
Hold the adapter up against your valve body until one matches the thread and/orshape. If you're still unsure, the table below lists the most common brands.
An add-on is a small cylindrical plastic extension included in the box. Fit it whenever the adaptor is RAV or M28x1.5 — it's needed with certain adapters because the valve body's pin sits too deep for the motor to reach on its own. The add-on simply lengthens that reach so the thermostat can press the pin fully.
Adapters sold separately
A few less common valve bodies need an adapter that isn't in the box: 28 Ă— 1 and 30 Ă— 1 (sold in packs of 5). Order the matching one before continuing if your valve falls into this group.
⚠️ Not compatible: Pettinaroli valve bodies cannot be used with the Valve ORIGINAL. If you have one of these, keep your original manual head fitted and get in touch with our support team about alternatives.
Step 2 — Fit the adapter (if required)
Take the adapter that matches your valve from the table above.
If the "Add-on required?" column says Yes, click the small plastic add-on into the adapter first.
Slide the adapter over the valve body and turn it clockwise until it's hand-tight.
Give the adapter a gentle wiggle to confirm it's seated squarely and won't wobble.
Tip: Never force an adapter that doesn't want to thread on. If it resists after a turn or two, it's the wrong one — back it off and try the next size. Cross-threading can damage both the adapter and the valve body.
Step 3 — Mount the Radiator Valve ORIGINAL
Make sure the thermostat is in its fully open (retracted) state before mounting. If you are not sure, take away and put back on the batteries: the product will reboot and set the motor to the fully opened position.
Line the thermostat up straight with the valve body (or adapter) and hand-turn the coupling ring clockwise.
Tighten until it's firm by hand — no spanner needed. The connection should feel solid with no play, but you should never have to force it.
Check that the Radiator Valve sits level and the display faces a direction you can read comfortably. You can adjust the display position by gently turning the valve without moving the coupling ring. You can adjust the orientation of the display later on if needed.
Good to know
The coupling ring is designed to be tightened by hand only. Using tools risks stripping the thread or cracking the housing, and it isn't necessary for a watertight, secure fit — remember, no water passes through this joint.
Congratulations, you can now finalize your installation throughout the app!
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