Description
This is a compact two‑piece radiator valve pack intended for conventional pumped central‑heating systems. It pairs a thermostatic radiator valve (the TRV2) with a manual lockshield that has an integrated drain‑off port (the LS1DO). Together they let you control the heat from a single radiator while giving you a simple way to isolate and drain that radiator for balancing, repair or replacement without emptying the whole system.
The thermostatic head uses a liquid sensor to modulate flow through the radiator as room temperature changes, and the lockshield provides the balancing and isolation function you expect from a wheel‑head or lockshield valve but with the added convenience of a drain‑off outlet built into the body.
Key specifications
- Temperature range (TRV): 7°C to 28°C
- Pipe compatibility: 10–15 mm pipework; 15 mm compression connection on the lockshield
- Radiator connection: standard 1/2″ BSP tail
- Max working pressure: 10 bar
- Body finish: chrome‑plated (pack variant descriptions include finish options)
- Pack contents: TRV2 thermostatic valve and LS1DO lockshield with drain‑off
How it works and what the parts do
The TRV2 is a conventional liquid‑filled thermostatic valve head mounted on an angled valve body. The liquid element expands or contracts with temperature, moving the valve pin to reduce or allow flow through the radiator. The head is reversible and can be mounted vertically or horizontally, and it includes a frost protection setting below 7°C. The TRV is intended to fit into standard radiator tails (1/2″ BSP) and suit 10–15 mm pipework.
The LS1DO replaces the conventional lockshield. It functions as a manual isolation/balancing valve but has a built‑in drain‑off port so water can be bled from the individual radiator when needed. That drain‑off saves a great deal of time during radiator replacement, local repairs or when flushing a system because you don’t need to drain the full heating circuit.
Installation, compatibility and practical notes
This pack is designed for fully pumped domestic systems and for use with typical radiator tails and 15 mm compression pipework. The valve bodies are bidirectional, so they can be installed on either flow or return and accommodate most site pipe runs. The TRV has a working range geared towards normal room temperatures (7–28°C), and the lockshield is supplied with a removable “witches’ hat” cap so it can operate either as a locked‑down balancing valve or as a wheel‑head when access is required.
Because the pack relies on standard 1/2″ BSP radiator tails and 15 mm compression connections, it is suitable for the majority of UK domestic installations. However, it is not a universal solution for larger radiators that use non‑standard tails, or for systems using larger pipework diameters; check pipe and tail dimensions before ordering.
Maintenance and the advantage of drain‑off
The standout practical benefit is the drain‑off port on the lockshield. For a plumber or heating engineer this is a useful time‑saver: you can isolate and drain a single radiator to replace valves, install a new radiator, flush debris or rebalance the installation without turning off and draining the entire system. The drain‑off is particularly handy in multi‑storey properties or where the boiler and header are in a remote location.
Routine maintenance on TRVs is straightforward: occasionally move the head through its range to prevent sticking, and ensure the lockshield remains accessible and capped if you want to keep it tamper‑resistant. As with any thermostatic device, the head senses air temperature — avoid covering it with curtains or radiator cabinets that interfere with accurate control.
Advantages and limitations
- Advantages: simple pairing of TRV and drain‑off lockshield; easy single‑radiator draining; reversible installation; standard connections for typical UK pipework.
- Limitations: designed for 10–15 mm pipework and up to 10 bar working pressure — not suitable for larger commercial pipe sizes; finish/colour variants exist so check the supplied finish if appearance is important.
In short, this is a practical, no‑nonsense valve pack for domestic or small commercial pumped heating systems where you want thermostatic control at the radiator and the convenience of local draining. It’s a sensible choice for installers and householders who need straightforward temperature regulation plus easier servicing and radiator swaps without major system downtime.
