@ Ralph

Hi Ralph, welcome to the forum. To take some advice from the great Douglas Adams, DON'T PANIC!

Its great you have a good monitoring system, which will make things a lot easier.

On the face of it I have a very similar system to you, 5 kW Samsung Gen 6, 5kWh battery and solar. Im paying about £40 a month over the year. Ive attached a graph of my HP usage for yesterday and you can see Im using 400-500 W on my heating.

Firstly given you heat loss, I would have thought 8kW was a bit big, but not overly so and it shouldn't cause you undue problems.

Im guessing that the big 3kW spikes in early morning are your Domestic Hot Water heating?, do you know when that is set for? Prior to that it looks like you are charging up your battery, is that correct?

Some information about the size of your house, its insulation levels and the outside temperature would be useful (with uk location)

Do you know how to access the FSV controller menu? Im assuming from your comment that you know you have Water Law activated.

Im guessing that to get you installation running optimally, there will be some tweaking of settings and also some use of time of use tariffs. What tariff are you current on?

If you look at my signature at the bottom of the post, it would be useful if you could add your details in a similar way, to help anyone picking up this thread later.

This graph is more similar to yours, unfortunately I cant show my battery SOC 🙁

@bontwoody Yes - charging batteries, followed by a hot water cycle. The following peaks are the HP in heating mode. It's running on the thermostat - when it calls for heat the HP starts at full power and then reduces the power when it hits the Water Law temperature. How do I add to my signature ??

On the next sunny day I'll wind up the thermostat and see what the HP does.

Tariff - IOG. All monitoring is via the Givenergy Portal i.e. power useage. As for the house - 135m2 3 bed bungalow, EPC band C. The HP is replacing an oil boiler. Location - North Dorset.

@raiph OK Ralph, we do indeed have very similar systems on the same tariff, so the good news is you should be able to get your bills to something approaching mine. One difference is that I dont use my HP to heat my hot water, I have a Mixergy cylinder and use the immersion overnight. Theoretically your DHW heating should be more efficient but if I were you the first thing I would do is make sure you finish heating your cylinder before the 5.30am tariff cutoff.

I dont use an external thermostat like Nest, just the internal one in the control unit which is in my living room. Apart from that I run on full weather compensation. I would need to see what settings you have in water law. The settings are in the installer menu under FSV. This video should show how but I think Graham had one of his settings backward if I remember correctly.

Your signature is in your Dashboard settings

Mark

Mark,

Gen7 has two water laws - one for 'floor' and the other for WL2-FCU i.e. rads. Guess what - the floor one is selected.

201* 15 & -2.0

202* 37 & 50

202* WL1 is 37 & 53

203* (WL2-FCU) 35 & 50

2041 is set to WL1 - Floor

So it could be a good idea to switch to WL2 and set the low to say 32 and high to 45.

Note that the 45degrees C is the radiator design flow temp at -1.9 outside.

@raiph Im not sure what the difference is between the two options Ralph, but Ive just checked and mine is also set to WL1. You definitely want to reduce your top end to 45 C Max. You might be able to go lower if you find heating is OK during cold weather.

Obviously you also want to get the bottom end as low as possible, but I find if I go less than 32C my radiators cant kick out heat quickly enough and so my heat pump cycles on and off. You will be able to spot that if it happens on your graph. I would keep it at a flow temp just above when that happens. My curve is set to 32C and 41C at the moment.

Do all that and you should be well on the way to lower bills 🙂 You can then decide if you are 24/7 kind of a guy or not 🙂

Thinking about it it doesn't make sense to have two Water Laws - or could it make sense if there is a mixer involved i.e. UFH and Rads.

Could be useful - set WL1 - try it for a week and then have different settings for WL2 and then try that for a week.

Nb. Thought I'd changed/added a signature - no sign of it ...

@raiph I forgot to ask how your radiators are set up. Hopefully no Thermostatic Radiator Valves. They should be balanced using the flow valves to get the room to the correct temperature. If they have TVR's then just fully open them.

Let us know how things go 🙂

@raiph Actually the 2 water law thing does make sense as the UFH would need different flow temps to the radiators and if there is no mixer valve then that is the only way to do it. I learnt something new there, every day is a school day 🙂

Re signature, maybe you didnt press the save button at the bottom of the page?

Are the graphs availailable direct from the Samsung Gen 7 (which I also have). If so how, please?

The Graphs are from the Givenergy portal. Anyone found the 'Smart Things' app useful?

Some rads have TRVs - all fully open. I've been trying to balance them using two thermocouples - I'll try a infrared camera next week if I can calibrate it.