Can you replace a hydronic heating GAS boiler with a heat pump?

Hydronic systems are widely recognized as one of the most efficient heating and cooling solutions, and you’ve likely already heard of their reputation if you’re reading this. Now, you may be wondering whether you can swap out your hydronic heating gas boiler for a heat pump.

The short answer is yes, you can. However, there are several important factors to consider when exploring this option to ensure a heat pump is a suitable choice for your home's location, budget, and current heating system.

This article will delve into these key aspects, highlighting the advantages and potential challenges of using heat pumps.

Important considerations when replacing a boiler with a heat pump

1. Required water temperature

Gas boilers often run at 60–80°C.
Most heat pumps run best at 30–50°C.

This is not ideal for radiators unless oversized.

2. System compatibility

What additional components may you require to the system to be operational.

• Sometimes a low loss header, expansion tank or circulating pump

3. Space for the outdoor unit

You’ll need:

• An outdoor heat pump unit (like an AC condenser) with good air flow

• A solid plinth structure

• Sometimes a buffer tank

4. Electrical capacity

The home may need:

• A dedicated heat-pump circuit

• In some cases, an electrical panel upgrade

But heat pumps use far less electricity than electric resistance heaters.

5. Costs verse Savings Investment

• Higher initial investment

• Often 30–70% lower running coats than gas

• Lifespan is similar to a boiler (12–20 years)

• Local regulations and incentives

6. Environmental Benefit

Heat pumps reduce:

• Gas combustion

• CO₂ emissions

• Indoor safety risks (no carbon monoxide)

• If your electricity is renewable → near-zero-carbon heating.

SO Should you replace your boiler with a heat pump?

Yes, you can replace a hydronic gas boiler with a heat pump, and it often works extremely well — but only if your home meets certain conditions.
For many homes it’s a smart long-term upgrade, but it is not ideal for every building without adjustments.

You are a good candidate if most of these are true:

1. Your radiators or underfloor heating can run at low temperatures

2. You have space for a heat pump unit.

3. Your home is reasonably insulated.

4. You want lower running costs

5. You want to reduce carbon emissions