Best flow settings for Daikon heat pump (ASHP) with Dimplex Smart Rads

Not stupid questions at all. How much information has your installer given you ? Do you know how they have set it up ? 

Having looked up Dimplex Smart Radiators they seem to be the complete opposite of mine ! Low thermal mass, very low water content, room by room control ?

Is your house a new build ? 

It was built in 1969. We have been in for 8 years the system was put in when we moved in. The ASHP works ok. It’s just the two smart rads at the end of the line that come on much later than all the others and go off much sooner. I am wondering if tweaking the the flow temp a bit higher may help, although not sure how to do this, is it called the LW temp?

Thanks for that, all helpful thank you. I think I am ok with the DHW settings etc.

my main issue is why those two rads at the end of line are operating as efficiently as all the others. I am just wondering if increasing the LWT will help. The LWT is currently set at 48 degrees C. 
 

I am also wondering what difference setting the weather dependency to ON, would have on the running of the system in general, economy wise and efficiency wise. 

I don’t know enough about your radiators to know the answer ! With my system I have all the TVRs open to keep flow unrestricted, it depends on a large volume of circulating water, that means I can have a lower flow temperature. I think that’s an ‘open loop’. I’m using the weather dependent curve and my flow temp is around 30 at 14 deg outside.

Great topic, great question @Boots and Bens. It will be helpful for anyone else looking for the same answer. 

Let me check if @amanda1 or @M.isterW can advise. Different heat pump, same question topic here:

Also I know @hydrosam’s Daikon experiences are something to be reckoned with. Perhaps they can advise. 

@Tim_OVO I’m not sure my Daikin experiences are a good thing to be sharing 😂

@Boots and Bens a lower operating temperature, or leaving water temperature will make the system more efficient. But you also have to keep in mind what temperature the system was designed to operate at. If you know your way around the settings you won’t do any harm dropping the temperature a couple of degrees, it’ll just take the house a little longer to warm up. However the Daikin unit you have is likely to be the same as mine and is not intuitive to operate. 
 

Regarding your two rads that aren’t getting warm, this is likely a balancing issue and changing temperature won’t make much difference. There are plenty of guides on line with advice on this, or call a competent heating engineer. Do you get it serviced annually? Maybe the same company could do that, or try a heat geek who’ll be able to check all the settings and set up the system optimally

 https://www.heatgeek.com/find-a-heat-geek/

Thanks for the info. Am I right in thinking that if I lower my LWT by a few degrees, it may be more economically beneficial but because it takes longer to reach the operating temp that will negate any benefit from lowering the temp of the LWT, of course that may be rubbish as I don’t really know.

is the LW the actual water that runs round the rads? Does this just keep circulating round, arriving back at a lower temp to be reheated again continuously until the temp set by the wall thermostat, 19, in my case?

What is the inlet water?

I have looked at info on balancing but cannot find anything on Dimplex Smart Rads.

Who are HeatGeeks please?

Thank you 

Hello ☺️

We have fan assisted rads (not the Dimplex ones but they work the same way). The issue with them is that they need a minimum water temperature to operate. For best heat pump efficiency you want the lowest flow temperature but if it's too low your rads won't work. We run a flow temp of 35. We don't use weather compensation because it can be tricky to use with fan assisted rads. You risk dropping the flow temp below a level that will trigger the rads. We already run at the lowest temp we can.

The reason the two rads come on later is because the other rads take the heat before it gets to them. This is a problem with most heating systems but you notice it because you can see when the rad switches on. You might get a small improvement by increasing your heat pump flow temperature but that will decrease the efficiency and increase your bills.

Actually, you might get better results all-round with a lower flow temperature. 48 is quite high for a heat pump. Heat your house slowly and don't let it get too cold. Expect the rads to stay on longer.