---
title: "Hydronic Heating Boilers in 2026: Repair, Replace or Switch to a Heat Pump"
date: 2026-09-06T07:00:00+10:00
author: Darren Burch
canonical_url: "https://sogeo.com.au/blog/hydronic-heating-boilers-repair-replace-or-switch"
section: Pages
---
![Stiebel Eltron Heat Pump]()

#  Hydronic Heating Boilers in 2026: Repair, Replace or Switch to a Heat Pump 

Your gas boiler is ageing, gas prices keep climbing, and Victoria is moving away from household gas. This guide walks through your three options honestly: repairing the boiler you have, replacing it with another gas unit, or switching to a hydronic heat pump that keeps your radiators. With the real numbers for each path.

 

 

 

 **Short version first.** If your hydronic heating boiler is under ten years old and has a minor fault, repair it. If it is older, or the heat exchanger is going, you have a fork in the road: another gas boiler at $5,500 to $9,000 installed depending on capacity, or a heat pump swap from $15,000 that keeps your radiators and runs at less than half the cost on your bills. This guide walks through all three options honestly, including the arithmetic.

## Why Everyone Is Suddenly Searching for Hydronic Boilers

Searches for hydronic heating boilers in Victoria have spiked hard this winter, and it is not hard to see why. A generation of gas boilers installed through the 2000s and 2010s is reaching end of life at the exact moment Victoria is winding down household gas. Gas tariffs keep climbing, new gas connections are already banned for new homes, and every boiler owner who gets a repair quote this winter is quietly asking the same question: do I really want to buy another one?

If your boiler is on its way out, you have three options. Here is the honest version of each. And if you are new to [hydronic heating](https://sogeo.com.au/blog/understanding-exactly-how-hydronic-heating-systems-work-the-basics-for-homeowners) itself, our homeowner guide covers how the system works.

## Option 1: Repair the Boiler You Have

If your boiler is under about ten years old and the fault is a component, a repair is usually the right call: pumps, sensors, valves, ignition parts and printed circuit boards are all replaceable. A boiler with a failing heat exchanger is a different story. That is the heart of the unit, the repair approaches the cost of a new boiler, and it is the point where money spent on the old unit is money wasted. The same is true when faults start arriving yearly: you are no longer maintaining a boiler, you are subscribing to one.

## Option 2: Replace It with Another Gas Boiler

A like-for-like gas boiler swap costs roughly $5,500 to $9,000 installed at 2026 Melbourne market rates, depending on the kilowatt rating: a standard 30kW unit typically lands between $5,500 and $6,500, with larger-capacity boilers pushing toward the top of the range. It is the cheapest number on the table today, and it deserves an honest health warning, because it is usually the most expensive decision over time.

Buying a new gas boiler in 2026 means signing up for another 15 or so years of gas bills, on a fuel whose price has risen consistently and whose future in Victorian homes is officially limited. It means paying the annual gas supply charge for the life of the unit. And it means that when the phase-out tightens, you own the appliance the market is moving away from. There are situations where it still makes sense: a rental with a short horizon, a home about to be sold, a budget that genuinely cannot stretch this year. For an owner planning to stay, the arithmetic below rarely favours it.

## Option 3: Switch to a Hydronic Heat Pump

This is the option the market is moving toward, and the reason is arithmetic, not ideology. A SóGeo gas-boiler-to-heat-pump swap that keeps your existing radiators starts at $15,000. Most installs run higher with home size, scope, hot water integration and any emitter or insulation upgrades the heat-loss calculation identifies. One thing we will tell you straight that many guides will not: there is currently no Victorian rebate for hydronic space-heating heat pump systems. The well-known programs cover hot water heat pumps, which are a separate measure, so if your project includes an eligible hot water upgrade they can apply to that part of the work. If a hydronic program opens, we will update this the week it happens.

What you get for the difference is a running cost transformation. The Stiebel Eltron units we install reach a COP of up to 5.40 at the standard rating point: every 1 kWh of electricity delivers roughly 4 to 5 kWh of heat. A typical Melbourne home spends around $900 to $1,350 per year on electricity with a heat pump system, versus around $4,100 per year running the same hydronic system on a gas boiler at current tariffs. Pair it with rooftop solar and daytime running costs can fall close to zero.

**The ten-year view.** Take the boiler route: roughly $5,500 to $9,000 today, plus around $4,100 a year in gas at current usage-heavy tariffs, and gas prices are not standing still. Take the heat pump route: from $15,000 today, plus around $900 to $1,350 a year in electricity. The gap on day one is real. The gap over ten years is tens of thousands of dollars, and it runs in the heat pump’s favour. That is why we call the cheap boiler quote the $6,000 trap in our [cost guide](https://sogeo.com.au/blog/how-much-does-it-cost-to-switch-from-gas-to-hydronic-heat-pumps).

Converting gas hydronic heating to electric? Our [guide to heat pump hydronic heating](/blog/heat-pump-hydronic-heating-melbourne-guide) covers sizing, running costs and why some heat pump installs leave a house cold.

 

 

  01 

 ![Hydronic Radiators]() 

 

### Will a Heat Pump Work with My Existing Radiators?

Usually, yes, and here is a trade secret that works in your favour. When most Melbourne hydronic systems were installed, few installers ran a proper heat-loss calculation. The common practice was a rule of thumb: floor area multiplied by 80 to 100 watts per square metre, or room volume at 35 watts per cubic metre. Those rules overshoot what most rooms actually lose, which means most existing systems are oversized. For a gas boiler, that was just waste. For a heat pump conversion, it is quietly good news: an oversized radiator has more surface area than the room strictly needs, so it can deliver full warmth at the lower water temperatures a heat pump runs best at.

A heat pump earns its efficiency by running cooler water than the 70 degree flow a gas boiler pushes, and surface area is what makes that possible. In practice, a SóGeo room-by-room heat-loss calculation usually confirms that most of your existing radiators can stay exactly where they are. Where a room does need more surface area, we swap the single panel for a double or triple panel of the same length in the same position, so the existing pipework coming through your wall or floor stays untouched and alterations stay minimal. The system is then engineered to hold a seasonal COP (SCOP) of 5 or higher across the year, and never less than 4 even on a demanding retrofit. An installer who quotes a heat pump swap without measuring heat loss is guessing with your efficiency, the same guess that oversized your system the first time. Our [radiators page](https://sogeo.com.au/hydronic-heating-cooling/hydronic-radiators-stylish-energy-efficient-heating-for-your-home) covers panel options.

 

 

  01 

 ![Pump room 2]() 

 

### What About Hot Water?

A hydronic heat pump can also take over domestic hot water with a stainless steel tank, typically adding $4,000 to $5,000 to the project. The hydronic heat pump is far more powerful than a dedicated hot water heat pump: it can reheat the tank in about an hour rather than four or five. One plant room, one electric system, no gas appliances left in the house, and the gas supply charge disappears from your bills entirely.

 

 

  01 

 ![SoGeo Team At Work]() 

 

### Is It Worth It?

SóGeo designs and installs hydronic heating systems across Melbourne. If you’d like a fixed quote for a boiler-to-heat-pump replacement or a new hydronic install, the next step is a site visit and a heat loss calculation.

Every install starts the same way. We come to the property, measure heat loss room by room, walk through your goals for the system, and write a fixed quote against the design. No estimates, no surprises, no pressure.

For a full overview of SóGeo’s hydronic service in Melbourne, see our pillar page on [hydronic heating Melbourne](https://sogeo.com.au/hydronic-heating-cooling). For the next-level read on heat pumps themselves, see our page on [air-source hydronic heat pumps](https://sogeo.com.au/air-source-heat-pumps). For boiler-to-heat-pump retrofits, see our [boiler replacement page](https://sogeo.com.au/replace-gas-boiler-hydronic-heat-pump).

 [Get a fixed quote from SóGeo.](https://sogeo.com.au/contact-us) 

 

  ## Common Boiler Questions

  ### How much does it cost to replace a hydronic boiler?

 ➕ A like-for-like gas boiler replacement costs roughly $5,500 to $9,000 installed in Melbourne in 2026 depending on capacity, with a standard 30kW unit typically between $5,500 and $6,500. Replacing the boiler with a heat pump while keeping your radiators starts at $15,000 with SóGeo. There is currently no Victorian rebate for the hydronic system itself; active programs cover hot water heat pumps as a separate measure.

   ### Can I keep my radiators and pipework?

 ➕ In most homes, yes. The pipework almost always stays. Radiators are assessed against a heat-loss calculation: most stay, and some are upgraded to larger panels so they deliver full warmth at the lower water temperatures a heat pump runs best at.

   ### Is gas being phased out in Victoria?

 ➕ Victoria has ended new residential gas connections for new homes and has a published direction of travel away from household gas. Existing connections continue for now, but gas tariffs have risen consistently, and a boiler bought today will live its whole service life inside that transition.

   ### How long does the switch take?

 ➕ Every SóGeo install starts with a site visit and a room-by-room heat-loss calculation, and you receive a fixed quote against the design before any work starts. The install itself is scheduled once equipment is confirmed, and your heating is typically only offline during the changeover itself.

  

 

  

## Our Partners

   [ ![Reece](https://sogeo.com.au/uploads/suppliers/_AUTOx96_crop_center-center_none_ns/Reece.png) ](https://www.reece.com.au/)   [ ![Stiebel Eltron](https://sogeo.com.au/uploads/suppliers/_AUTOx96_crop_center-center_none_ns/Stiebel-Eltron.png) ](https://www.stiebel-eltron.com.au/)   [ ![Mitsubishi](https://sogeo.com.au/uploads/suppliers/_AUTOx96_crop_center-center_none_ns/Mitsubishi.png) ](https://www.mitsubishielectric.com.au/)   [ ![Purmo](https://sogeo.com.au/uploads/suppliers/_AUTOx96_crop_center-center_none_ns/Purmo.png) ](https://www.purmo.com/au)   [ ![Viessmann](https://sogeo.com.au/uploads/suppliers/_AUTOx96_crop_center-center_none_ns/viessmann_wordmark_rgb_1_vitorange.png) ](https://www.viessmann.com.au/)