If you don’t want your outdoor pond to completely freeze over during winter, you can use a pond heater, to help keep the surface ice-free.
This is important, as it allows your pond to continue to ‘breathe’. There is nothing wrong with having some ice on the surface of your pond in winter, and goldfish will survive in the water underneath – but they need at least a small gap in the ice, to allow oxygen in, and toxic gases out.
There are several different types of pond heater – some ‘de-icer’ types are designed simply to create this small, artificial blowhole in the surface ice, whilst others are electric or gas-powered, and can significantly increase the overall temperature of your pond.
To help you choose the best pond heater for you, we’ve put together this selection of 5 of our favourite options, based on their effectiveness, durability and value for money.
Last update on 2021-04-16 / All Pricing & Imagery from Amazon Product Advertising API
There’s no way Jack Frost will be able to get through these!
Our best pond heater is easy to install, energy-efficient, and provides your pond with a breathing hole when it freezes over
Cost: Price not available
Topping our selection of the best pond heaters is this Affinity Ice Vent Pond Heater by Blagdon, which is suitable for use with ponds of up to 5,000L.
This heater is designed to stop the surface of your pond completely freezing over, by retaining a hole through which your pond can breathe, and support the aquatic life within.
It features a low wattage, convection design, which means it only requires a minimal amount of energy to function. This makes it both eco-friendly, and more economical for you.
To install the heater, simply attach the green float to the top of the heating element, and place this on the surface of your pond. Plug it into an outdoor waterproof socket, and switch it on. When the freezing temperatures have passed, you can either turn the device off, or leave it on, ready for next time.
The heater is suitable for use in temperatures down to -10°C, and ponds with a maximum depth of 1.2m. If your pond is bigger than 5000L, you can install multiple Ice Vents. Overall, this heater offers great functionality for a reasonable price – and will keep your fish healthy and happy.
- Stops pond surface from completely freezing.
- Convection design preserves energy, making it more eco-friendly and economical.
- Suitable for most small ponds, up to 5,000L.
- Multiple heaters can be used in larger ponds.
- Easy to install.
- No plug included – you will need to source one separately.
- No LED light to show that it’s working.
Our best value pond heater is a highly affordable option, that will still create that all-important hole in the ice in freezing temperatures
For our value pick, we’ve chosen this 150W Superfish Pond Heater. It has a durable stainless steel casing, and is designed to float on your pond’s surface.
It works in the same way as our best pick, to heat a small area on the surface of the pond, and keep it ice-free. This allows gaseous exchange to continue, providing your fish with essential oxygen, and keeping them healthy.
Again, this one requires next to no set up – you simply attach the float, place it in the pond, and plug it in. The wide float is made from a buoyant Styrofoam, which is highly effective at keeping the heating element upright.
Although some users report receiving a 3-pin plug with their purchase, most state that it in fact comes with a European 2-pin plug. In this case, you’ll need to purchase a UK adaptor, before it can be used.
The cable on the heater is 5m long, which might be enough to reach your power source, or you may require an extension lead, depending on your pond location and set up.
Ultimately, this heater offers much the same functionality as the Blagdon, but for a lower price, and is perfect for pond owners on a budget.
- Made from durable stainless steel.
- Designed to keep a hole in the ice, to prevent your pond’s surface from completely freezing over.
- Buoyant Styrofoam float keeps the heater upright.
- Includes a plug (European 2-pin style).
- Low-priced – one of our most affordable pond heaters.
- Requires an adapter to plug into a UK socket.
- 5m cable means you may also need an extension lead.
This floating, 150W pond heater has a similar style to those above, but comes with a longer cable, and a higher price tag
Cost: Price not available
The Aquael Pond Heater has a metal heating element that will keep an area of your pond’s surface ice-free, ensuring toxic gases can leave the pond, and oxygen can enter, preventing your fish from suffocating.
There are 2 models available in this design, 150W or 300W. This 150W model draws less power, making it more environmentally-friendly and economical, and great for smaller ponds.
It comes with a cable of 10m in length, which also makes more suited to those with larger gardens, and ponds further away from their outdoor power source.
To install the heater, simply place it in your pond, and turn it on at the plug. As with the other floating heaters, the heat output is fixed, and there’s no thermostat to allow you to control the temperature.
This is our most expensive floating pond heater, and we wonder whether it’s really worth spending the extra money, when the device itself is almost identical to our previous two heaters.
However, it is another perfectly functional, durable and high-quality pond heater, and if you do choose this one, we’re sure you won’t be disappointed.
- Designed to always keep a small, artificial blow hole in the surface ice on your pond.
- Long 10m cable is ideal for larger gardens.
- Quick and easy to install.
- Requires zero maintenance.
- Our priciest pond heater in this floating style.
- No plug included.
Our most affordable pond heater is a great way to keep your fish safe over winter, without breaking the bank
Cost: Price not available
If you’re looking for a more affordable option, this 150W Floating Pond Heater by Finest Filters is currently the cheapest pond heater on our list.
This 150W model is recommend for use in ponds of up to 10,000L. If your pond is larger than this, the manufacturer advises purchasing their 300W or 600W model instead.
The float on this one is smaller in diameter than some of the others we’ve featured, which you may prefer as it takes up less space in your pond – although it might not be as stable.
It has a 5m cable, which again might be a little short for some gardens, and means you may need to add an extension lead. It does, however, come with a 3-pin UK plug, for your convenience.
It really couldn’t be simply to install this heater; there is no assembly required, and you don’t even need to add a plug adapter – it’s ready to go, straight out of the box.
Ultimately, this pond heater may not be quite as sturdy as those with larger floats, but it will still do the job of keeping a hole in the ice on your pond, so your fish can survive winter – and it’s the most affordable option here.
- Our cheapest pond heater.
- Suitable for ponds of up to 10,000L (most small garden ponds).
- Also available in a 300W and 600W version, for larger ponds.
- Includes 3-pin UK plug.
- Easy to install, ready to go straight out of the box.
- 5m cable might be a little short for some gardens – you may require an extension cord.
- Float is a little smaller than on similar designs, and may make the heater less stable.
A powerful 2KW whole pond heater, with a built-in thermostat and low pressure flow switch
Our final pond heater, this Cloverleaf PHEAT2KW Thermo Control Heater, offers a different design (and price bracket) to all our previous heaters. This one is designed to heat the whole body of water in your pond, not just a small hole in the surface ice.
The heater has an IP55 rated waterproof body, and optional rigid or flexible pipe connections. It comes with a 1.5m cable to be plugged into the electricity source, and should be installed near the return pump outlet of your pond. There’s a low pressure flow switch, which will turn the heater off if the water flow drops below 4000 lph, to prevent damaging the heater.
At 2KW, this is easily the most powerful heater on our list, and the only one that will make any real difference to the overall temperature of your pond. The temperature can be adjusted using the built-in thermostat. Some online users do report a problem with the thermostat, in that it sometimes settles significantly above the temperature you’re aiming for, so watch out for this.
Other than the occasional faulty item, the main drawback of this one is the price – it’s considerably more expensive than all our other pond heaters. However, it’s not really fair to compare this one to the other heaters, as it’s a completely different style, and produces different results. There’s no doubt that this heater is in another league.
Overall, this is a pricey option that won’t be for everyone, but if you need something that will actually heat your pond water, and not just make a hole in the ice on the surface, this should do the job.
- Powerful 2KW pond heater.
- Strong and durable construction.
- Waterproof to IP55 rating.
- Built-in thermostat allows you to set the desired temperature.
- Includes low pressure flow switch.
- Easy to install.
- Our most expensive pond heater.
- Connections don’t sit flush to the mounting point on the heater, so it can’t be mounted to a wall, unless first mounted to a piece of plywood, or similar.
How To Heat A Fish Pond In Winter
The best way to reliably heat a fish pond in winter is to use a pond heater. Most of the pond heaters we’ve featured here are designed to float on the surface of your pond, creating a localised heat that will prevent the area around it from freezing, and provide a breathing hole for your pond through the ice.
This type of de-icer pond heater provides a marginal increase in the temperature in the immediate vicinity of the heating element, but is not designed to significantly heat the water in the pond.
If you want to heat a whole body of water, you will need to use an inline electric pond heater, such as the Cloverleaf Thermo Control Heater. This type of heater actually heats the water that’s pumped through it, eventually raising the overall temperature of the pond.
Another important way you can keep your pond warm in winter is through good insulation – this can make a huge difference, even to an unheated pond. You can also cover your pond, to prevent heat loss at the surface.
Heating A Pond For Tropical Fish
Some tropical fish can be kept outside in the UK during summer, but most will not survive in sub-zero temperatures. It is therefore not enough to just keep some of your pond’s surface ice-free in winter – if you have this type of fish, you’ll need to either bring them inside, or properly heat your pond.
To heat an outdoor pond to a temperature suitable for tropical fish to survive, you will need either an inline electric heater, or a gas-fired boiler system – something that can heat the whole pond, and do so reliably.You will also need your heater to have a built-in thermostat, so you can set the water temperature to meet the specific requirements of your fish. Properly meeting the needs of tropical fish in an outside pond in winter can be difficult, so make sure to do thorough research first, and if you’re in any doubt, bring them inside until spring.
April is a freelance writer who specialises in writing about home and garden design and the environment. She is an avid wildlife-enthusiast and adventure-seeker, and feels happiest when in the Great Outdoors.