@heatgeek Isnt the DT steady at 5C? The only time I can percieve it isnt is when starting up and its trying to get to temperature. The flow and return temperatures seem to track well. Or am I missing something?
I am curious as to what would be the effect of choosing a different DT. I think 3C is selectable in the menus somewhere.
House-2 bed partial stone bungalow, 5kW Samsung Gen 6 ASHP (Self install)
6.9 kWp of PV
5kWh DC coupled battery
Blog: https://thegreeningofrosecottage.weebly.com/
Heatpump Stats: http://heatpumpmonitor.org/system/view?id=60
@bontwoody If you look at the diagram, at 19.00 when power is over 3kW, the DT is 5C. If you look around 11.00 when power is ~2kW, then DT is 3C. In both cases, flow is constant around 9 l/min.
Private individual. No affiliation with commercial "Heat Geeks" of same coincidental name.
I think I basically understand the principle, but I still feel like there's something I'm missing.
I've just been there, it's 17° outside, the controller (in the cupboard in the coldest part of the house) is reading indoor temp of 26°, and the radiators are still getting heat.
I don't understand what 'high OAT end of the WC curve' means in your explanation.
I assume WC means weather curve and FT flow temperature?
Where can I find flow temp adjustment?
I already adjusted the weather compensation as described in the video bontwoody linked to Outdoor temp for water law. Low 13°. High -2°
Is this what you are referring to in your explanation?
I've lowered them again, this is what I see.
Posted by: @pooneilI think I basically understand the principle, but I still feel like there's something I'm missing.
I've just been there, it's 17° outside, the controller (in the cupboard in the coldest part of the house) is reading indoor temp of 26°, and the radiators are still getting he
Assuming your system is running on water law only the indoor temperature registered by the controller doesn't matter. It goes solely (in this mode) according to the value of the temperature registered outside. Days like today when its cold but there is high solar gain can definitely cause an6y heating to heat too much during the daytime, hence using either the temp sensor in the controller or TRVs as a limiter (ie setting them a couple of degrees above the desired temperature). Days like today are also lousy days to adjust weather compensation!
You currently have your WC curve set at 17 @ 10C OAT and 30 @ -2C, thats assuming you are running on water law 1 (there are 2). In the installer menu you can tell which water law you are running on by the value of FSV (field setting value - essentially parameter) 2041. Alternatively if you can tell what the outside temperature is (in the shade) we can check its following the curve. If its running on WL1 and the outside temp is >10C you would expect the rads to be at 17C which wouldn't feel warm, so Im a bit suspicious its either not running on WL or it is running on WL2.
17@10COAT is a bit weird. More normal would be something like 25-30 (water temperature out) @15-20 (OAT). Do you have UFH? Im guessing this property is rather well insulated and/or a flat so contributions to warmth other than the heating can make a big difference.
If you send some more screenshots it may be possible to work out whats going on.
4kW peak of solar PV since 2011; EV and a 1930s house which has been partially renovated to improve its efficiency. 7kW Vaillant heat pump.
Posted by: @jamespa17@10COAT is a bit weird. More normal would be something like 25-30 (water temperature out) @15-20 (OAT). Do you have UFH? Im guessing this property is rather well insulated and/or a flat so contributions to warmth other than the heating can make a big difference.
It was originally set at the numbers you suggest are normal. I've adjusted them down, in increments, to where they are now as per the video link.
It's a 3 bed house, about 90sqm over two floors. It's very well insulated. No UFH.
Posted by: @pooneilPosted by: @jamespa17@10COAT is a bit weird. More normal would be something like 25-30 (water temperature out) @15-20 (OAT). Do you have UFH? Im guessing this property is rather well insulated and/or a flat so contributions to warmth other than the heating can make a big difference.
It was originally set at the numbers you suggest are normal. I've adjusted them down, in increments, to where they are now as per the video link.
It's a 3 bed house, about 90sqm over two floors. It's very well insulated. No UFH.
OK, quite small, well insulated. In terms of setting up the heat pump at present solar gain is your enemy.
A few more questions, if you are able
- Detached, semi/end terrace or terraced?
- Does it get lots of solar gain?
- Can you confirm the value of FSV2041?
- Can you send some screenshots of the controller.
- When you say the rads are feeling warm, how warm? If its running on WL1 and OAT is 17 (in the shade) they shouldn't feel warm at all.
4kW peak of solar PV since 2011; EV and a 1930s house which has been partially renovated to improve its efficiency. 7kW Vaillant heat pump.
Semi detached. One side is south facing, with large windows in the living room and main bedroom. There's definitely some solar gain.
I think it on WL1, see above. But I don't know if the 'floor' bit is right. The only other option was WL2
The rads don't now feel as hot as they did before I reduced the WC.
What pics if controller would you like?
@pooneil Here are my settings. Keep 201* at 17C and -2C and just lower 202* a little. Notice in 202* at the top it says "For WL1 Heat" and my 2041 setting is WL1 so you know you have the right Water Law.
As James says its difficult on days like today to get it right. Remember the higher flow temperature is when its -2C outside and the lower is for when its 17C outside.
House-2 bed partial stone bungalow, 5kW Samsung Gen 6 ASHP (Self install)
6.9 kWp of PV
5kWh DC coupled battery
Blog: https://thegreeningofrosecottage.weebly.com/
Heatpump Stats: http://heatpumpmonitor.org/system/view?id=60
@heatgeek I see what you mean, I couldnt read the figures when looking at my phone screen and I assumed the gap was a DT of 5C which it has been through the winter. My best guess is that my radiators are struggling to lose enough heat at the moment to maintain a DT of 5C. There is also a fair bit of noise as the control system tries to adjust to the most recent data which makes reading difficult at times.
House-2 bed partial stone bungalow, 5kW Samsung Gen 6 ASHP (Self install)
6.9 kWp of PV
5kWh DC coupled battery
Blog: https://thegreeningofrosecottage.weebly.com/
Heatpump Stats: http://heatpumpmonitor.org/system/view?id=60
Keep 201* at 17C and -2C and just lower 202* a little.Posted by: @bontwoody
But isn't that what it was before, when it was too hot and the rads were still throwing out heat?
What would you suggest I set 202* to?
I still don't understand, if there's a full tank of water and the house is hot, why the system has to operate at all.
Say it's mid summer and 28° outside, plus solar gain inside, is the system still going to be running 24/7 ?
@pooneil OK, I dont think you have really got the understanding of how weather compensation works yet.
The 17C and -2C are markers for when the heat pump is heating your house. Above 17C outside it wont turn on. At 17C it will and the flow temperature in my system will be 33C. At -2C outside the flow temperature in my system will be 40C. Between those two outside temperatures the flow temperature will be somewhere between 33 and 40C in my system.
If you house is too warm you need to drop the 33C and 40C settings FSV 202*. Try 30C and 35C and see how you get on.
If its still too hot then lower them a bit more. I will attach a file explaining things in more detail in another post.
House-2 bed partial stone bungalow, 5kW Samsung Gen 6 ASHP (Self install)
6.9 kWp of PV
5kWh DC coupled battery
Blog: https://thegreeningofrosecottage.weebly.com/
Heatpump Stats: http://heatpumpmonitor.org/system/view?id=60
- 22 Forums
- 2,078 Topics
- 45.6 K Posts
- 93 Online
- 3,359 Members
Join Us!
Trusted Installers
Struggling to find a reliable heat pump installer? A poor installation can lead to inefficiencies and high running costs. We now connect homeowners with top-rated installers who deliver quality work and excellent service.
✅ Verified, trusted & experienced installers
✅ Nationwide coverage expanding
✅ Special offers available
Latest Posts
-
RE: All your heat pump problems solved by -- a plate heat exchanger in a plinth!
@iaack of course, you're right, but that's not the mark...
By AllyFish , 3 hours ago
-
RE: Say hello and introduce yourself
@transparent thanks for this, good info. Worth making a...
By MatWin , 3 hours ago
-
RE: Renewable Heating Hub Homeowners' Q&A Podcast
In our latest episode, we hand the mic to four homeowne...
By Mars , 2 days ago
-
RE: Forum updates, announcements & issues
@andrewj I’m currently away and only back this weekend....
By Mars , 2 days ago
-
This is very interesting - I have just had my ASHP spli...
By heat-pump-newbie , 2 days ago
-
RE: Help Stop the MCS Heat Pump Monopoly
Response sent. Thank you for highlighting the document...
By Sheriff Fatman , 2 days ago
-
RE: I worry I've messed my Samsung settings up somehow
Yes , this time of year . Unfortuneately I dont have ...
By Alfapat , 2 days ago
-
RE: Feasible solutions to expand existing Sunsynk battery capacity
Ours is a loft installation, which is where both invert...
By Sheriff Fatman , 2 days ago
-
RE: 5 Star Service from Havenwise
@sheriff-fatman Exactly this is why a lot of our users ...
By HCas , 3 days ago
-
RE: Solar Thermal DHW and ASHP
I'm beginning to think solar thermal is something that ...
By Alex_N , 3 days ago
-
RE: Commencing on an ASHP Installation Process
I received the BUS Grant permission email yesterday eve...
By Sheriff Fatman , 3 days ago
-
RE: Solar Power Output – Let’s Compare Generation Figures
510kWh of solar PV from my 4kW Hyundai panels and SMA S...
By JulianC , 5 days ago
-
RE: Is my Samsung heat pump working too well?
Thats in itself is interesting. I have a Vaillant heat...
By JamesPa , 5 days ago
-
RE: Jokes and fun posts about heat pumps and renewables
@transparent Not a swell season then ☹️
By Toodles , 5 days ago
-
RE: Air Changes per Hour - ACH and the MCS requirement
update - my old installer insisted on a heat loss of 11...
By MatWin , 6 days ago
-
I agree it's not very helpful. Generally, the max heat ...
By Old_Scientist , 6 days ago
-
RE: Why Your MCS-Certified Installer Might Not Be As Competent As You Think
Hive and most other smart thermostats don't play well w...
By JamesPa , 1 week ago
-
RE: Enabling WiFi: Samsung ASHP on Smart Things App
Thanks for the input. I've been running various experim...
By Grahamh-uk , 1 week ago
-
RE: Radiators downstairs are cooler at the bottom after ASHP install
@melonbuffet Hi, this sounds great is you are getting 5...
By ASHP-BOBBA , 1 week ago
-
RE: Ripped Off: How UK Homeowners Are Paying Gas Prices for Wind Energy
I believe there's another reason that network upgrades ...
By Transparent , 1 week ago