Get to know your Daikin heat pump
Stay cosy and in control with guidance and support on how to use your Daikin heat pump

Check out our recommended schedule for the Cosy Octopus tariff.

Head back for advice on saving money and how the heat pump works in your home.
Troubleshooting
Why aren’t my radiators hot?
The radiators will still be warming up your home even if they’re not very hot to touch. If your room is comfortable and the thermostat is the right temperature, then everything’s working fine – even if the radiator is lukewarm or cool. When it’s very cold outside, you’ll notice your radiators get warmer.
If the thermostat looks right but the room still feels a bit chilly, you could:
- change the heating schedule, so it’s warm at different times
- turn up the target temperature by a degree or two
- open the valves and check the system pressure
If things still don’t look quite right
Most issues can be fixed with a little heat pump TLC (maybe the radiators feel colder at the top, or your hot water isn’t as hot as you’d expect). The first things to do are:
- Open the radiator valves and bleed the radiators
- Check and adjust the water pressure in your heat pump
See the guidance below for tips on how to do this.
If you've done the above, but your heat pump is still not hitting temperature, it might be that the ‘leaving water’ (the water circulating through your radiators and/or underfloor heating) is too cold. You can change that in the control panel settings. See this video for a guide.
- Scroll through the main menu and choose ‘main zone’.
- Use the right hand dial to raise the temperature slightly and press the left hand dial to confirm.
How to open valves and bleed your radiators
There are two simple things you can do to keep your radiators in good nick and make sure your heating levels stay stable.
- Open the valves
A lot of radiators have thermostatic valves, so you can regulate the heat in each room. They’re very handy, but they can get stuck sometimes.
All you need to do is turn them all the way in each direction before setting them back to where you want.
- Bleed any air out of the radiators
You’ll know for sure they need it if they’ve got cold spots at the top. You’ll need a radiator key and a rag or cloth.
Pop the key in the valve and turn it slowly anti-clockwise, holding the cloth underneath, until you hear air hissing out. Hold there until a bit of water spits out (that’s what the cloth is for). Then close the valve again firmly, turning clockwise. Check out this video for a demo.
If you’ve had to bleed your radiators, it’s quite likely your water pressure has dropped. So check that next.
How to check and adjust water pressure
Your heating system relies on water being at a certain pressure to work efficiently. Over time, the pressure can ease down, like air from a car tyre. It can also be affected if you change anything, like bleeding the radiators. Here’s how to keep it in good shape:
- Make sure the system is cold before you start
Switch off the heat pump, and let the pipes cool down.
- Check the cold water pressure
There’s a pressure gauge attached to the pump, or you can use the control panel. When the system is cold, the pressure should be between 1 and 1.5 bar.
- If it’s lower than 1 bar, top up the system with water
This is the hands-on bit. When you look at the heat pump, you’ll see a section with either a lever or flat-headed screws at either end of a flexible, braided hose. This is your filling loop.
- You’ll need to turn the levers or screws slowly to let water into the system. Two things to remember:
- Make sure the pump’s off and the water in the system is cold
- Turn the levers or screws one at a time
They only need a quarter-turn. Keep your eye on the pressure gauge as the water is flowing in.
As soon as the gauge reaches 1 bar, shut the levers or screws off again. You don’t want the system pressure going too high.
Note: when your pump is on and the water is hot, you might see a higher pressure. That’s nothing to worry about: it goes up and down a bit while it’s working. But if the cold water pressure falls lower than 1 bar, the system won’t work as well as it should.
Why is the outdoor unit smoking or dripping?
It’s most likely defrosting. When it’s cold, your pump will automatically run a cycle to clear any built-up ice . It’s actually steam, not smoke, and a bit of melted ice. So it might look a bit dramatic, but it’s actually a sign everything’s working as it should be.
Why is it showing an ‘AH’ error?
The short answer is that it didn’t finish disinfecting the hot water in the tank. Leave it a week, and it should run another cycle and clear the error. If it hasn’t by day 8, give us a call.
The long answer: once a week, your hot water cylinder runs a disinfection cycle. That should happen some time when you’re unlikely to run the hot water, like in the early hours. But if someone, say, runs a bath during that time, it stops the process. And that shows up as a warning until it runs the next cycle. Don’t worry: skipping a week won’t cause any problems.
How to reconnect your heat pump to Wi-Fi
If you've changed Wi-Fi router or internet provider, and your Daikin app has been disconnected from the internet, follow the steps on this guide to re-establish your Wi-Fi connection and get your heat pump back online.
Still feel like something’s not right? Get in touch.
If you can't find what you're looking for, get in touch...
Call us: 0808 196 6842
Email us heat@octopus.energy
Our aftercare phone lines are open 8am – 8pm Monday to Saturday, 10am - 6pm Sunday. There are other ways to get in touch too.
If you'd like to make a complaint, find our complaints procedure here.

How to use your heat pump controls
Check out our video guides for more support with your Daikin heat pump controls.
How to use your thermostat

How to set a schedule with your Daikin control panel

Downloadable user guides
Get to know your heat pump
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