Heat Pump - KwZ usage through the roof

Reed_Richards

I have a horrible feeling we have seen the last of the OP.  

matelodave

Perhaps they are gathering all the info that we requested so that they can get a well considered answer  or on the other hand, another one day wonder 

Spoonie_Turtle

Reed_Richards said:

I have a horrible feeling we have seen the last of the OP.  

They were last active on the 20th, and it's now a bank holiday weekend that they might be busy spending with family and/or friends. 


As a general comment because I see this a lot on the energy board, we can't assume when someone asks for advice that the topic of their post will be their main focus until they've sorted it, especially when it's something not immediately urgent (even if it is important - importance and urgency are two separate things).  Regulars having time and capacity to be on here a lot doesn't mean everyone does, even if they are asking for help

Reed_Richards

Fair enough, it's summer now and none of us are likely to be spending a lot on heating.  But £5,500 per year!!!!  

JEdelman

First of all, thanks for all the replies and for taking the time to try and help. That’s very kind. 

I’ve taken the advice, contacted Heat Geeks and have a recommended engineer coming in October to carry out an inspection. 

The 17,000 referred to is the estimated usage from British Gas this year on the latest bill. They have carried out meter readings since we moved in. 

With regards to further info, the house is 174 square metres. Energy rating on the certificate is: B. Hot water comes from main system. It’s electricity only. There is no gas. 

The pump is a LG THERMA V Air-to-Water Heatpump 50Hz 220-240 V. 

We have underfloor heating downstairs, radiators upstairs and the temperature is set at 21C daytime (0600-2200) and 18C night-time. 

Thanks again. 

Reed_Richards

Welcome back, @JEdelman, sorry I lost faith that you were coming back.

I too have an LG Therma V hear pump.  If you don't mind, we'll take a look at the settings and see if they seem sensible.

Does the display on your controller say AI or does it show a temperature, if so what temperature?  

For the benefit of others AI is what LG calls its Weather Compensation, if that is not engaged then the temperature shown will be the set Leaving Water Temperature.  

JEdelman

Excuse the ignorance, but I'm not 100% what you mean by control panel. There is a panel on the wall of the garage that says 50 degrees with a temperature icon, and 50 degrees with a shower icon next to it. Is that the one?

Reed_Richards

That's the one.  That means that your hot water cylinder is set to 50 C (shower icon) and the target temperature of the water leaving your heat pump for the central heating is set to a constant 50 C.  This is sub-optimal for economy but I can't believe it would push your bills up to the massive levels you are experiencing.

This panel could act as a standalone controller for your heat pump but not when it's in the garage.  So you must have a third party controller, the thing you use to set temperatures.  Can you tell us what the make and model of this is, please.

Also, where is your hot water cylinder?  It's not also in the garage, is it?    

JEdelman

Yes - the hot water cylinder is also in the garage. Literally next to that controller. The heat pump itself backs onto the garage, on the other side of the wall from the cylinder. The thermostats we use to set the temperatures with in the house are Heatmiser. 

Reed_Richards

It's a pity that the hot water cylinder is in the garage as that places it outside the heated fabric of your house and in a cold environment.  So it will lose heat more rapidly than if it were shut inside a warm airing cupboard and the heat it loses is wasted.  As a new build that seems pretty terrible; makes me wonder how careful the builders were about other forms of insulation.  Or is it better situated than I am imagining?  Are the water pipes to and from the cylinder well insulated?

It's important to ensure that your controller does not allow your heat pump to operate in short cycles.  I read the Heatmiser instructions here: https://www.underfloorheatingsystems.co.uk/wp-content/uploads/2024/02/Heatmiser_neoStat_Manual_27022017.pdf and I'm pretty sure you would achieve this by setting optional setting 04 to 15.  Without changing the setting, can you please look and see what value is set and let us know.  Follow the instructions in the link if you don't have a printed copy.  "15" would set a 15 minute delay from when the heat pump goes off until it is allowed to come back on again.