Do Heat Pumps Need Servicing?

(What Most People Get Wrong)

Heat pumps are often sold as “low maintenance” systems.

That’s technically true… but also dangerously misleading.

Low maintenance does not mean no maintenance — and in many cases, heat pumps actually require more specialist attention than traditional systems to run efficiently.

The problem is, a lot of homeowners are never told this.

The Biggest Myth: “Heat Pumps Don’t Need Much Servicing”

You’ll hear it all the time:

“They’ve got fewer moving parts than a boiler”

That’s true.

But what’s usually left out is this:

A heat pump is a fully integrated system — not just a box outside your house.

It relies on:

• Correct system design

• Accurate flow rates

• Balanced emitters

• Proper controls setup

• Efficient hot water production

If any of those are wrong, the system can still “work”… but perform badly.

And that’s exactly what we see every day.

The Real Problem: Not All Servicing Is Equal

The “Quick Tick Box” Service

Many services today focus almost entirely on the outdoor unit:

• Clean the coil

• Check the fan

• Look at electrics

• Tick a few boxes

Done in 30–45 minutes.

The problem?

That’s only a fraction of the system.

A Heat Pump Is Not Just the Outdoor Unit

A proper service should include:

• The cylinder

• Internal pipework

• Pumps and flow rates

• Controls and settings

• System performance

Ignoring the indoor side is like servicing a car by only checking the tyres.

Installers vs Service Engineers (The Truth)

This is where things get interesting.

Two Different Skillsets

• Installers focus on getting systems fitted and running

• Service engineers focus on diagnosing, measuring, and optimising

You’ll find some engineers who are excellent at both.

But in many larger companies:

• Installation teams are under time pressure

• Servicing is treated as a quick follow-up job

• Engineers may not fully understand system performance

In some cases, the same company that installed the system is servicing it.

Which raises a fair question:

Are they going to identify their own mistakes?

The Commissioning Problem

A huge number of heat pumps were:

• Rushed in during the grant boom

• Poorly commissioned

• Left running on default settings

We regularly see:

• Incorrect flow rates

• Poor delta T

• Oversized or undersized systems

• Badly set weather compensation

The system runs…

But not efficiently.

And that costs money every single day.

What Manufacturers Actually Say

This is where the “low maintenance” myth really falls apart.

Most manufacturers require annual servicing to maintain warranty.

• Annual servicing is often a condition of warranty validity

• Missing services can void warranties completely 

• Typical warranties last 5–10+ years, but only if maintained properly

Some even include servicing in installation packages specifically to protect the warranty.

That tells you everything.

What MCS & Industry Guidance Says

The Microgeneration Certification Scheme (MCS), alongside the Energy Saving Trust, sets the standards for heat pump installations in the UK.

Their guidance makes it clear:

• Systems must include maintenance requirements and servicing provisions 

• Installers should follow best practice across the full system lifecycle 

• Proper servicing supports performance, compliance, and consumer protection

In simple terms:

Servicing isn’t optional — it’s part of the system design.

How Much Should a Heat Pump Service Cost?

This is another area where people get caught out.

Typical UK pricing:

• £150–£300 for a basic service

• £250+ from manufacturers like Vaillant

But here’s the key point:

A proper full-system service takes time.

If someone is:

• In and out in under an hour

• Only checking the outdoor unit

• Not measuring performance

You’re not getting a full service.

Why Heat Pump Servicing Often Costs More Than Boilers

There’s no combustion, no flue, and fewer safety checks.

So why is it more expensive?

Because:

• It’s a performance-based system

• Requires measurement and analysis

• Involves the entire heating system

• Needs optimisation, not just inspection

A gas boiler either works… or it doesn’t.

A heat pump can be:

• Working

• But inefficient

• And costing you far more than it should

  
  

The Hidden Cost of Poor Servicing

This is the big one.

A poorly serviced heat pump can:

• Run at lower efficiency (higher bills)

• Cycle incorrectly

• Struggle with hot water

• Wear components faster

• Develop faults earlier

Even small issues like:

• Slightly low flow rate

• Incorrect curve settings

• Poor insulation

Can have a huge impact over time.

What About Grants and Protection?

There are currently:

• Grants to install heat pumps (Boiler Upgrade Scheme)

• But no grants to fix or replace a poorly performing system

Once it’s in — it’s your responsibility.

And if:

• The installer disappears

• The system wasn’t set up properly

• The warranty is invalid

You’re left with the bill.

What Should a Proper Service Include?

A real service should involve:

System Performance

• Flow rates (heating + hot water)

• Delta T measurements

• Pressure checks

Outdoor Unit

• Coil condition

• Fan operation

• Electrical checks

Indoor System

• Cylinder performance

• Immersion heater

• Pipework insulation

Controls & Optimisation

• Weather compensation

• Heating curves

• Schedules and settings

Not just a quick visual check.

Final Thoughts

Heat pumps are brilliant when they’re set up and maintained properly.

But the idea that they’re “fit and forget” is one of the biggest myths in the industry.

The reality is:

• They require regular, proper servicing

• They need ongoing optimisation

• And when neglected, they can cost far more to run

If you’ve invested thousands into a heat pump, it makes sense to protect that investment.

Because with heat pumps…

How it’s set up and maintained matters just as much as the unit itself.