There will be quite a few pumps. I am assuming you mean the water pump? The compressor does what it says on the tin, it compresses the refrigerant which has two sides, an evaporator and a condenser. The evaporator has a cooling effect (like sweat) the other side, the condenser, removes heat from the air via compression - in the most basic explaination. The refrigerant gas has a very very low boiling point which makes all this magic possible. Then you'll have the heat exchanger through which your heating water will pass, forced along with the pump.

Thanks balalto. Do I mean the water pump ? You mean what pumps through the radiators and tank coil ?

Here's the display from my indoor system:

When the system is running the 'Pump" is shown as ON. The Compressor is nearly always ON too. Only once have I seen the pump ON and the compressor OFF. 

I can see how many hours each has run ie:

@heat-pump-newbie I don't know your system, but that pump will undoubtedly be the heating water pump. The compressor is generating your heat. They won't always run together. For example the compressor might turn off when the heating water is up to temperature but the pump continue to circulate water until the return water temperature drops to a certain level. Then the compressor will cycle back on to raise the temperature back up.

Posted by: @heat-pump-newbie

Thanks balalto. Do I mean the water pump ? You mean what pumps through the radiators and tank coil ?

Here's the display from my indoor system:

When the system is running the 'Pump" is shown as ON. The Compressor is nearly always ON too. Only once have I seen the pump ON and the compressor OFF. 

I can see how many hours each has run ie:

 

Hi Newbie,

So you're not quite an Oldbie yet?

One of the problems is that different manufacturers sometimes refer to the same device slightly differently.

Looking at your top photo, the Pump will probably be referring to the water pump, which because you have a split system, will be located within the indoor unit.

The Compressor is what compresses the refrigerant gas and is used to extract the heat energy from the air, and this will be located within the outdoor unit.

The Backup Heaters are used to supplement the heating of the water by the heat pump and are located in the primary water circuit (the water that goes around your radiators). YOU DO NOT WANT TO USE THE BACK UP HEATERS UNLESS YOU ARE FREEZING TO DEATH.

The Booster Heater is what would normally be called an immersion heater, and is located on your hot water cylinder. This heats the water that you use in your shower and hot water taps (the secondary or sanitary water). I know, very confusing. 🙄 It is more efficient to heat the water in your hot water cylinder using the heat pump, rather than the booster heater, unless the booster heater is being supplied from a solar PV system.

Batalto is correct, except that he got the Evaporator and Condenser the wrong way round. The refrigerant gas condenses in the Condenser, and in doing so transfers heat energy from the refrigerant gas into the primary water. The Evaporator extracts heat energy from the outside air and in doing so transforms the refrigerant from a liquid to a gas. Simples. 😮 

I did a more detailed explanation somewhere on the forum, but don't ask me to find it. 🙃 

@derek-m that'll teach me to write replies on my phone late in the evening

No, I am very much still a newbie !! Thank you both for your replies. The fog is clearing... 

@heat-pump-newbie 

That's much better than being an ancientbie like me. 😒 

Derek. I've had a look at the running time screens and discovered that the back up heater has run for 3 hours for space heating. I haven't logged this before so I have no idea when that happened. As the pump has run for 1487 hours I'm not too worried ! I'll keep an eye on it from now on, but I presume I have no control over it coming on, it'll just do it automatically when it is needed ?

Posted by: @heat-pump-newbie

Derek. I've had a look at the running time screens and discovered that the back up heater has run for 3 hours for space heating. I haven't logged this before so I have no idea when that happened. As the pump has run for 1487 hours I'm not too worried ! I'll keep an eye on it from now on, but I presume I have no control over it coming on, it'll just do it automatically when it is needed ?

Hi Newbie,

If you look in section 8.3.3 Heat source settings on page 61 of the Installer reference guide, you will find the relevant details. You have a choice, you can disable the backup heaters, or enable them, but set the ambient air temperature below which they can be used. The default settings would appear to be enabled and -4C.

Ok, thanks. I'll have a look at that after Christmas and pray for mild weather in the meantime !! Thanks for all your help. 

Hi Newbie, 

I have the same system as you and can confirm what was said above. 

Seeing as Daikin claim the heat pump works down to -25c I really do not understand why the backup heater would ever be needed in the UK except as the result of a failure. 

Any questions please feel free as I have had to learn this interface as it was not very well set up initially. 

Do you have access to the system on your phone through the Daikin App? I have just ordered a LAN access box as it was not installed originally and really want more data than what is available on the little screen. 

Cheers,

Adam