Air source heat pump - Grant

mishy1965

Hi everyone, I am after a bit of advice please.  I had a Grant airsource heat pump fitted last year.  I have turned my thermostat off as i dont need the heating now its summer..  The installers told me my water was set to come on twice a day 6 - 8 am and 4 - 6pm. is this right.  There is only me and my daughter in the household and we use an electric shower so the water is only really for washing dishes and when i have a bath in the winter.  my elect bills are working out at about £4-5 a day now its summer.  i have no idea how to change the settings either.  do you think i need to change the settings for the water to come on less. Am so confused by this. wish i had kept my boiler it was so much easiere.  Any help or advice would be really appreciated.  Many thanks. 

Alnat1

Find the off switch and boil a kettle to wash the dishes, will cost you pennies instead of pounds.

mishy1965

Will it affect or damage the pump if i do this? 

shinytop

mishy1965 said:

Hi everyone, I am after a bit of advice please.  I had a Grant airsource heat pump fitted last year.  I have turned my thermostat off as i dont need the heating now its summer..  The installers told me my water was set to come on twice a day 6 - 8 am and 4 - 6pm. is this right.  There is only me and my daughter in the household and we use an electric shower so the water is only really for washing dishes and when i have a bath in the winter.  my elect bills are working out at about £4-5 a day now its summer.  i have no idea how to change the settings either.  do you think i need to change the settings for the water to come on less. Am so confused by this. wish i had kept my boiler it was so much easiere.  Any help or advice would be really appreciated.  Many thanks. 

You should have got a manual with your ASHP.  If not, contact the installer.

We have our water on for one hour per day and this is plenty for two of us.  That used less than 50kWh or £17 in the last month  We set it to 3-4pm when it's warmer outside and therefore cheaper to run the ASHP.   We have it at 45 degrees because any hotter is unnecessary and expensive.  

Is your £4-5 per day just for the ASHP?  Is there anything else that could be using a lot of energy?

Using a kettle for washing up/hand washing is a daft idea.  If you boil a kettle every time you wash up, go to the loo, before you eat or cook, after you've dug the garden, etc., it will cost more than pennies and also be a right pain.   

If you can't get a manual via your installer, there is a Grant one in the link below.  It might not be the right one for you though.  If you are still struggling, post a question in the forum in the link below.  There are some people with Grant ASHPs who will be able to help.  In fact post there anyway; you'll learn a lot.

https://renewableheatinghub.co.uk/renewable-heating-hub-download-directory

MikeFl

I'd echo what Shinytop said - one hour a day should be sufficient, especially with newer HW cylinders. The Grant controllers can be a little fiddly to change and you should have been left with a manual. Try the renewableheatinghub forum, or contact Grant themselves. 

mishy1965

thank you all, very helpful indeed. much appreciated 

mishy1965

just an update, i spoke to an electrician and he talked me through how to change the water to 1 hour a day.  He said it was cheaper to have it run at night?  Do you agree with this or would it be better to change it to the afternoon as i have solar panels? TIA

matelodave

better to run it when you've got free leccy from solar rather than overnight.

Spoonie_Turtle

mishy1965 said:

just an update, i spoke to an electrician and he talked me through how to change the water to 1 hour a day.  He said it was cheaper to have it run at night?  Do you agree with this or would it be better to change it to the afternoon as i have solar panels? TIA

It's only cheaper at night if you have Economy 7 (in general), BUT with solar panels you can run it for free using free energy when they are generating.

Reed_Richards

Spoonie_Turtle said:

 BUT with solar panels you can run it for free when they are generating.

Not necessarily free.  It depends on how the maximum/typical output of the solar panels is by comparison to the (maximum) power your heat pump requires to heat your hot water.  In my case my solar panels (4.8 kW peak) cannot provide enough power on their own as my heat pump takes 6 kW peak when heating the hot water.

matelodave

Its still got to be cheaper to run it during the day when the sun is shining than overnight unless you've got a really low off-peak tariff

I've had an Efergy energy monitor on my 11kw Daikin and I've never seen it peak above 4kw even when its running flat out.

 A lot will depend on how its controlled, mine is inverter driven and so has a slow startup. If you stand close you can hear the motor and the fans slowly wind up to maximum

I guess that some heatpumps may have capacitor start motors which could take a high inrush current as the compressor or fans start but I shouldn't think that there are many nowadays