Air Source Heat Pump

misterNJ

Bought a one off build house. It has Air source heat pump. Transition from gas heated home to this in Jan is a bit of shock to me. At best the house is 16-17 degrees, water is like warm to warm . The point of heating is I need it when it’s cold outside. 

How can I supplement the sub optimal heating that this air source heating provides during very cold days?

Any options apart from portable electric heaters in each room ?

what options are there  for hot water on cold days? 

lohr500

If you haven't done so already I would get an engineer who really understands ASHP to look at the system and determine if the unit is big enough to heat the house.

It may be the case that the system hasn't been set up correctly by the previous installer and just needs the settings adjusting, or it could be a more fundamental problem that the unit hasn't got the capacity for the size of the property.

Verdigris

Heat pumps are at their most efficient when the flow temperature is low. To compensate for the lower water temperature you need to run them for longer.

This thread may help:

https://forums.moneysavingexpert.com/discussion/6240076/i-bought-a-heat-pump#latest

As suggested, above, getting the installer to take you through the controls will give you a head start.

Reed_Richards

Because you bought a new build it's possible that your heat pump was not installed by an MCS accredited installer.  If it had been there are procedures that must be followed to make sure your heat pump is properly sized and that your radiators  or underfloor heating are of sufficient capacity to keep your house warm.  It sounds as if either your heat pump is under capacity or your heat emitters are undersized or the settings on your heat pump are incorrect and the water temperature is too low.  So I would go along with @lohr500 's recommendation; get an engineer who really understands heat pumps to look at it. 

Verdigris

If it's a new-build wouldn't it be covered by NHBC guarantee?

shinytop

misterNJ said:

Bought a one off build house. It has Air source heat pump. Transition from gas heated home to this in Jan is a bit of shock to me. At best the house is 16-17 degrees, water is like warm to warm . The point of heating is I need it when it’s cold outside. 

How can I supplement the sub optimal heating that this air source heating provides during very cold days?

Any options apart from portable electric heaters in each room ?

what options are there  for hot water on cold days? 

Unless the ASHP is undersized you won't need to. If you give a few more details we can help. House size (m2), ASHP size, radiators/ufh, thermostats, etc.  Most builders don't have a clue about ASHPs and set them up wrong.  In most cases it's easily fixed. 

It's -1C outside and my ASHP heated 1990 house is actually a bit warm at nearly 22C and there's plenty hot water for a bath if I want.  Today will be an expensive one at about £9 but there aren't many like this.  December was about £150 for heating at Ofgem cap rates. 

I'm sure it can be sorted out.        

Reed_Richards

misterNJ said:

what options are there  for hot water on cold days? 

My heat pump keeps my hot water cylinder at 50 C and I then have a mixer which cools this down a bit before it comes to the hot taps.  To reach 50 C it has to pass water at about 55 C through the coil inside the cylinder. I have never yet encountered a cold day when it cannot do this and don't expect to.

What temperature is your hot water cylinder set at, @misterNJ?  

Mineral1

"My heat pump keeps my hot water cylinder at 50 C"

Thats too low; it should be stored at at least 60C to prevent legionella growth. 

Verdigris

Thats too low; it should be stored at at least 60C to prevent legionella growth

Not quite right. You have to raise the temperature to 60 degrees+ once a week.

matelodave

my heat [ump heats the water to 45 dgrees which is fine however, like most heatpumps it has a periodic sterilisation function which boost the temperature to 60. Mine does it weekly on Saturdays but I can decide when, how long, how hot and even disable it if I want to.

I can have the water at whatever temperature I want when I want, but anything over 50-55 degrees requires the immersion heater to activate which increases the running costs

I agree with ShinyTop and Reed_Richards that iprovided the system has been sized and installled correctly it either hasn't been set up properly or more than likely the OP hasn't learned how to use it correctly.

Reed_Richards

Verdigris said:

Thats too low; it should be stored at at least 60C to prevent legionella growth

Not quite right. You have to raise the temperature to 60 degrees+ once a week.

Which my ASHP system does automatically, as did the gas boiler in my old house.  Once a week for about one hours the tank temperature is raised to 60 C.