TRVs and Heat Pumps: What You Need to Know (and Why We Often Take Them Out)

If you’ve got a heating system that’s more than a few years old, chances are you’ve got TRVs—thermostatic radiator valves—on most of your radiators. They’ve become standard issue in homes across the UK.

But here’s the thing most installers won’t tell you: when it comes to heat pumps, we often remove TRVs altogether. And no, it’s not a mistake. In fact, it’s key to making your system work properly.

Lockshield Valve

What TRVs Actually Do (and What People Think They Do)

There’s a common myth that turning a TRV from “5” to “2” turns the radiator down in the way a dimmer switch turns a light down. It doesn’t.

Here’s the truth:

• A TRV doesn’t control the temperature of the radiator.

• It controls the temperature of the room at which the valve closes or reopens.

  
  

So when your TRV is set to 3 (about 20°C), it allows water to flow through the radiator until the room reaches that temperature. Then it shuts the flow off.

This is fine when you’ve got a gas boiler running at high temperatures—but with a low-flow, low-temp heat pump, this behaviour can cause problems.

Why TRVs Don’t Work Well with Heat Pumps

Heat pumps work best when water flows continuously and evenly throughout the entire heating system. They don’t "blast" heat into your rads like a boiler. They warm them gently over time, and for that to work, the water needs to circulate without restriction.

TRVs cause problems in three ways:

1. They restrict water flow, reducing heat output and making rooms feel cold.

2. They cause pressure imbalance, especially in larger homes with lots of radiators.

3. They often lead to noisy systems—with rushing, whooshing or vibrating pipes when the system tries to push more water through half-closed valves.

   
   

This is why, for most rooms, we replace TRVs with standard lockshield valves on both sides of the radiator. It keeps the system open, balanced and quiet.

Lockshield Valve

What If You’re Worried About Rooms Getting Too Hot?

Good question—and a fair one.

In heat pump systems, the whole house is typically heated at a steady temperature, which avoids the cycle of overheating and overcooling you may be used to with a boiler. That means:

• Bedrooms stay comfortable without being stuffy

• Living rooms maintain a stable warmth

• You won’t get sudden heat surges—even with big radiators

Still concerned? We do sometimes keep TRVs in specific rooms, like:

• South-facing rooms with lots of glass, where solar gain can spike temperatures

• Bedrooms, where you'd prefer less heat

  
  

In those cases, we don’t use just any old TRV. We use the Altecnic Ecopac - a high-quality, large-aperture TRV that minimises water flow restriction.

Altecnic Ecopac TRV and Lockshield

Summary: What We Recommend

• No TRVs by default: We use lockshields on both ends for optimal flow.

• TRVs only where truly needed, and we use ones that won’t restrict your system.

• Educated choices: Most people misunderstand how TRVs work. We’ll help you use them correctly if you really need them.

• Custom advice for every home: This isn’t one-size-fits-all. We’ll design the system that works best for your rooms, your lifestyle, and your comfort.

  
  
  
  

Not Sure What to Do With Your Radiators?

We’ll tell you straight: some of them may need changing, some may be fine. The only way to know is to do a proper heat loss assessment—and that’s what we do every day. You can read more about radiator choices on this blog.

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 📐 Request a heat loss survey - email info@yourenergyyourway.co.uk

 📩 Or just drop us a message—we're happy to demystify it all