Do you think a Samsung air source heat pump is using too much electricity?
This past week at Freedom HQ we have received a few requests for help with perceived high running costs, so we have put together this article to help out.
Please note that the following information has been put together with Samsung Heat Pumps in mind, but can be applied to many different heat pumps
It’s always assumed that the whole electricity bill is the heat pump, but this is not the case. What is the background usage (lights TV, internet hot tub etc.)? This could be anywhere from 0 to 100% of this bill.
We need this figure to tell us what’s going on and so we can deduct this from the bill to work out the heat pump run cost. It’s always a good idea when doing this work to take an energy meter with you, kill the power to the heat pump and measure the background use when you are there as it really helps. You need to bear in mind you should expect heating bills of over £100 a month in winter and nothing in summer as you aren’t heating the property.
Please bear in mind that viewing the efficiency of a heat pump at a single moment (i.e. in the middle of winter at night) isn’t the best way to understand it’s efficiency. You need to view the electricity costs over an entire year to best understand how efficient the unit is. You should find that 1kW of electric provides around 3.5kW of thermal energy over an annual period. Any deviation from this would definitely be worth looking in to.
In many regards, the complaints we are seeing are related to confusion as opposed to issues with the equipment. For instance, a customer may understand that the run cost of their heat pump is £1000 per annum. Many people will take that figure and divide by 365 to get to £2.73 per day. Any cost above this rings alarm bells… In actual fact, the run cost will be reflective of the usage/ season. In August it may cost 10p a day to run whereas in the height of winter it could be closer to £10 a day. Over the entire year, this will even out to the £1000 the customer originally expected.
If you still believe you are seeing high run costs please check the following:
It’s possible that the heat pumps are not set up right causing high run costs.
The stats are calling for heating all year long. (surprisingly common)
The stats are not connected to the heat pump, either wiring errors field setting 2091 not set to 1, etc.
From Nov 2018 onwards you can set 2091=3. This stops the unit when it gets to the weather comp set point which can save money.
There are towel rads keeping the unit running all year long.
Does the unit stop when you turn all your thermostats off?
With AU on the screen, the unit should only heat when a run signal is sent into terminals B22 or B24 on the unit. Switch off the thermostats and test whether you have voltage at these terminals still.
The tank stat is too low in the cylinder so the immersion is on all the time
The tank stat is not fully in the cylinder. If it’s pulled out it can’t see the tank temperature.
There is a recirc pump dragging the tank down all the time bringing in the immersion.
Is the tank temperature measured by the unit accurate, test this by measuring the temperature of the water coming out of the cylinder and compare it with the measured temperature using the view button on the controller? If the tank temperature sensor is reading low the immersion will run constantly.
See video here: http://www.youtube.com/watch?v=WbwDZ5vU4GM
Check that field setting 3032 is set correctly. This is the delay before the immersion comes in. We usually set 20 min delay in 3032 for a 200L cylinder or 60 mins for a 300L cylinder.
Check the hot water set temperature is NOT above 48C, press the oval set button and adjust with the + or – button
If you are seeing this email as an end user, your first port of call should always be the installation engineer who originally installed the equipment. They will know your installation, and the heat load of your property best, and will be able to advise if they believe the running costs are too high.
Alternatively, if you are an installation engineer, and are concerned that your customers run costs are high, please do not hesitate to contact us on firstname.lastname@example.org or 02380 274 833