British Gas Heat Pump installations

Reed_Richards

I can't speak for what Matt does but one way some people deal with solar gain is to set the room thermostat a couple of degrees higher than they want to room to be.  That acts as a backstop and stops the room getting seriously hot when you are trying to heat with some method that generally does not involve the use of interior thermostatic controls.  

matt_drummer

I don't use a thermostat to control the temperature of the house.

I just turn the heating on when the house isn't warm enough and turn it off when it is warm enough.

It's not ideal in some respects but it's easy to control the heat pump from the app on my phone.

We are not that sensitive to the actual temperature as long as we are warm enough. A bit like the summer, no heating but some days are warmer than others.

I do have the Madoka and it is situated in a part of the house that is the best representation of the whole house. If I used it, the temperature would be OK as the thermostat is somewhere that is not affected by solar gain. It's in the hallway in the middle of the house.

Solar gain is a natural event and we just accept it, you are sitting in the sun and it will feel warmer.

Where you put your Hive thermostat will affect when your heating comes on and goes off, so place it somewhere that works for you.

Our lounge enjoys solar gain too.

I run quite low flow temperatures, so even if the heating is on, as a room gets warmer the heat output of the radiators drops. This is because the difference between the room temperature and the mean flow temperature through the radiators gets smaller and this reduces radiator output.

It is self regulating, so even though the solar gain adds heat it also reduces radiator output and so the heating never just piles in loads of heat once a room is warm.

Either by luck or by judgement, I am able to run a fixed lwt and get a house that is somewhere between 21c and 23c with the heating on.

But every house is different.

I am sure mine works like it does because the radiators are so big, I wouldn't expect every house to work like this.

It takes time to set up a heat pump to suit the house and its heating system.

The best advice I have is to install some monitoring. It makes it possible to visualise what is going on and allows you to see the affects on changes pretty much instantly.


Heat given out by radiators is nothing to do with the actual temperature, it is the change in temperature between inlet and outlet and the volume of water flowing that determines the heat given off.

My radiators are never more than luke warm and generally around room temperature.

stripling

oliver1951 said:

Just an update and to see if there are other with British Gas instals. Had mine installed mid June 2024. It’s a Daikin altherma 3 8kw, with a mixergy cylinder and a hive controller. Hasn’t had much use until the last two weeks so trying to work out how to utilise it. But have got a problem with the hive controller, at least it is thought the problem is with the hive controller. That problem is that as soon as it drops a tiny bit below the target temp it fires up again and as soon as it’s passed it, it stops again and repeat, so I spotted I was getting multiple 2-3 minute cycles. NOT GOOD. So I am having to watch it like a hawk and as soon as it hits the target dial the temp back a few degrees to stop it from going off again. I’m trying to gauge ( whilst also waiting to try and get a permanent fix for the problem from BG/hive/Daikin) what temperature I should let it drop to before I restart to get an efficient next cycle. What I have noticed is that across the cycles I have run so far I have been getting a heating gain of around 0.5c per hour. I have also noticed, by looking at my smart meter info, that the first hour of a cycle is using about 1.7kwh v 1.4kwh for each subsequent period. And even though the gain in temp towards the end is significantly less, the power consumption hasn’t changed. If anyone has a view on these things please do respond.

I have a Daikin Altherma 3 - 6kw.  I had quotes from both BG & Octopus - I went with 🐙.  I've had it a couple of weeks now so still getting used to it. However, as soon as my excellent 🐙 installers left I dived into the MMI and changed my weather compensation curve from the 50º 🐙 design for to 40º. I tweaked a few other settings a wee bit too.

This week I have lowered it again to 38º and it is currently running on a Leaving Water Temperature (flow temp) of 28º and my house is a fairly uniform 21-22º (except one room still waiting for a radiator).  It has used about £1.32 of electricity today.  Hopefully, it will be tweaked even lower when a radiator gets changed in a week or too (there's a national shortage of K3s right now).  Of course, it's not freezing cold yet. 

There's a lot of very happy Daikin owners around the planet - they've been making these things for a very long time and installers rate them. At the end of the day it's not about heat pump brand it's about a good installation and learning to use your MMI

I'd ditch that Hive if I was you. I'd make sure all TRVs are wide open and I'd go watch some  Heat Geek videos - specifically the 2 on using the Daikin MMI and weather compensation. There's a very helpful 🐙 (unofficial) Daikin Facebook group that you could join (they won't care it's a BG installation) to ask questions for support from other owners. Or the super supportive Renewable Energy forum. 

There's quite a few YouTube videos on weather compensation which is your best bet for economy and efficiency. Once you have that set up properly your heat pump should more or less run itself. Make sure the water tank is not eating electricity by not being set up correctly - depending on your needs. I only heat my tank once a day in the early hours. (Although that will go out of the window when the teens visit and have 30 minute showers.)

My heat pump is running very well so far but I have invested a bit of time into learning how to operate it and working by trial & error. . My installers were just really good and knew that once my system was 'officially commissioned' I would be in those settings doing my own thing.  (They even labelled every pipe in my plant room so I know what's what). The golden rule of tweaking settings is to keep a note of things before you change them so you can trace your route if necessary. Do read your installation manual - it's not great (none of them are) but it's better than a poke in the eye with a blunt stick. 😁  

oliver1951

@stripling, thanks for your comments. You seem to have progressed well in a short time. I’m on weather comp now, bg came and changed the settings and the hive is basically just a thermometer now. So it’s on all the time, well it’s switched on but it seems fitful in how it works, not what I was expecting. So my upstairs seems to be warm, but the heat pump doesn’t seem to be heating downstairs at all which is odd. The temperatures downstairs have been on the decline since moved across to weather comp. Because of the way my install had to be done, the circuit hits upstairs first. So maybe those rads are gobbling all the heat? Anyway I moved my Trv settings to eco to see if that would help the situation downstairs, but no joy. Will email BG  and see if they have any sensible suggestions. It’s using about 8kwh per day at present, but not producing the goods for downstairs. 

stripling

@oliver1951
You can't just expect to hit 'weather compensation' and forget it. Or at least not until it's set up correctly for your particular property - it's a bit 'trial and error' depending on your heat loss etc.,. because it's about tweaking the numbers on the two axis of the graph.

You really need to learn how to use the basics of the MMI - specially the curves. There's other settings to tweak too including modulation. Weather compensation should be tweaked in small increments. Take a note of current settings, tweak, observe for a day or two. Take note, tweak, observe. Leave the TRVs open for now - heat pumps need an open loop to run efficiently. Maybe your radiators may need balancing too? Think about the location of the Madoka/thermostat (if you have one) because the temp of that will influence temps everywhere - if the location reaches the set point it isn't going to know that other places haven't. BG should've taken this into consideration in their design.  

But go and watch those videos I linked to - it will help you to get it running well. You can't really call British Gas for every tweak - although they should've got it running properly, at least at their own design temp of 45º, from the beginning. There's lots of helpful information online if you look for it. Plus there's several YouTube videos by actual owners of Daikin Altherma 3s who talk about how they run them. 

oliver1951

stripling said:

@oliver1951
You can't just expect to hit 'weather compensation' and forget it. Or at least not until it's set up correctly for your particular property - it's a bit 'trial and error' depending on your heat loss etc.,. because it's about tweaking the numbers on the two axis of the graph.

You really need to learn how to use the basics of the MMI - specially the curves. There's other settings to tweak too including modulation. Weather compensation should be tweaked in small increments. Take a note of current settings, tweak, observe for a day or two. Take note, tweak, observe. Leave the TRVs open for now - heat pumps need an open loop to run efficiently. Maybe your radiators may need balancing too? Think about the location of the Madoka/thermostat (if you have one) because the temp of that will influence temps everywhere - if the location reaches the set point it isn't going to know that other places haven't. BG should've taken this into consideration in their design.  

But go and watch those videos I linked to - it will help you to get it running well. You can't really call British Gas for every tweak - although they should've got it running properly, at least at their own design temp of 45º, from the beginning. There's lots of helpful information online if you look for it. Plus there's several YouTube videos by actual owners of Daikin Altherma 3s who talk about how they run them. 

@stripling. Thanks. I have over the past 3 months watched every heat geek video, ever. Daikin videos and many many more. And I am testing in a controlled way. But tweaking the curve will not address the disparity of heating between upstairs and downstairs. 

Reed_Richards

oliver1951 said:

@stripling, thanks for your comments. You seem to have progressed well in a short time. I’m on weather comp now, bg came and changed the settings and the hive is basically just a thermometer now. So it’s on all the time, well it’s switched on but it seems fitful in how it works, not what I was expecting. So my upstairs seems to be warm, but the heat pump doesn’t seem to be heating downstairs at all which is odd. The temperatures downstairs have been on the decline since moved across to weather comp. Because of the way my install had to be done, the circuit hits upstairs first. So maybe those rads are gobbling all the heat? Anyway I moved my Trv settings to eco to see if that would help the situation downstairs, but no joy. Will email BG  and see if they have any sensible suggestions. It’s using about 8kwh per day at present, but not producing the goods for downstairs. 

Where is your Hive thermostat situated?  If the set temperature in that room is, say, 22 C and the room never gets that warm then the heat pump should be on all the time.  If you turn the upstairs TRVs to Off (or frost protection) then upstairs should get cold whilst all the output from your heat pump is directed downstairs.  If your downstairs still does not get warm enough then your Leaving Water Temperature is set too low.  Increase it until downstairs reaches your desired temperature.  If you can achieve that then you need to reduce the flow to your upstairs radiators so they don't make upstairs too hot when downstairs is good.

oliver1951

Reed_Richards said:

oliver1951 said:

@stripling, thanks for your comments. You seem to have progressed well in a short time. I’m on weather comp now, bg came and changed the settings and the hive is basically just a thermometer now. So it’s on all the time, well it’s switched on but it seems fitful in how it works, not what I was expecting. So my upstairs seems to be warm, but the heat pump doesn’t seem to be heating downstairs at all which is odd. The temperatures downstairs have been on the decline since moved across to weather comp. Because of the way my install had to be done, the circuit hits upstairs first. So maybe those rads are gobbling all the heat? Anyway I moved my Trv settings to eco to see if that would help the situation downstairs, but no joy. Will email BG  and see if they have any sensible suggestions. It’s using about 8kwh per day at present, but not producing the goods for downstairs. 

Where is your Hive thermostat situated?  If the set temperature in that room is, say, 22 C and the room never gets that warm then the heat pump should be on all the time.  If you turn the upstairs TRVs to Off (or frost protection) then upstairs should get cold whilst all the output from your heat pump is directed downstairs.  If your downstairs still does not get warm enough then your Leaving Water Temperature is set too low.  Increase it until downstairs reaches your desired temperature.  If you can achieve that then you need to reduce the flow to your upstairs radiators so they don't make upstairs too hot when downstairs is good.

Hi Reed, the hive thermostat is out of the picture now, with it running on the weather dependent operation. I agree but turning the upstairs rads to eco and subsequently off, made no difference to downstairs at all. Turning the LWT up likewise had no effect. So I’m thinking there is some other issue. TVR’s on downstairs rads (DR) on back to front ( if that’s even possible) so they are on max but are really off. Strange thing is while the DR have always been colder and seemingly less effective than the upstairs rads, while I was using the hive they did work. Since switching to weather dependent they don’t. Maybe coincidence. What puzzles me is the water is flowing, the heat pump is clearly working because upstairs is very warm around 21c. Too warm for my taste but one is in test mode. It’s an odd one.

As a by the way the hive lives in the sitting room, target is 18c, but as I say it doesn’t affect anything now. It did before but not now. But then before the hive itself was the problem. 

Reed_Richards

Are you quite sure the Hive has no effect?  I have a third party room thermostat in my downstairs living room, a Drayton Wiser in my case.  And another one elsewhere for a second zone.  When both zones have reached the temperature set on their room thermostats then the heat pump is turned off for heating.  This applies whether or not I use Weather Compensation on my heat pump, and I really believe that will be the norm.  So why not play safe and set your Hive to 22 C?   Either that will make no difference or it will have an effect.

Another feature of my system is that I have a pair of radiators that are prone to an air lock on the pipes feeding them.  Those radiators don't get warm when the air lock is there, even though no gas comes out if I bleed them.  The way I clear the air lock is to turn most of the other radiators off so the full power of the pump is directed into the blocked section.  Could you have an air lock somewhere?   

oliver1951

Reed_Richards said:

Are you quite sure the Hive has no effect?  I have a third party room thermostat in my downstairs living room, a Drayton Wiser in my case.  And another one elsewhere for a second zone.  When both zones have reached the temperature set on their room thermostats then the heat pump is turned off for heating.  This applies whether or not I use Weather Compensation on my heat pump, and I really believe that will be the norm.  So why not play safe and set your Hive to 22 C?   Either that will make no difference or it will have an effect.

Another feature of my system is that I have a pair of radiators that are prone to an air lock on the pipes feeding them.  Those radiators don't get warm when the air lock is there, even though no gas comes out if I bleed them.  The way I clear the air lock is to turn most of the other radiators off so the full power of the pump is directed into the blocked section.  Could you have an air lock somewhere?  

So I read your note and I turned the thermostat up AND IMMEDIATELY there was a gurgle in the radiator, albeit in the bedroom. Also the hive flagged up that it was heating. So I’ll monitor it overnight and hope it doesn’t suddenly go into short cycling, though why it should I don’t know. But equally, as I only have one zone and one thermostat, (which was set at 15c, by the way, which was just to see what weather dependent would do and ensure hive was not interfering,) then I still don’t get why upstairs is warm and downstairs is not. 

On the air lock, I don’t think so, but I have only done as you did bleed all the rads. I’ll look into that one. It’ll be interesting to see if this makes a difference. If it does I’ll probably be even more confused, content, but confused. I’ll let you know how it goes. 

7am update: It worked. So all rooms seem to be advancing on a common temperature. The downstairs rooms are now within a degree of the upstairs rooms. Weather today is going to be poor for solar energy ( thru the windows anyway) so perfect day for continuing to see what it does. 

@ReedRichards  Reed were you suggesting 22c, as a pleasant temp, or because the higher setting doesn’t disrupt the heat pump, which clearly it has for me with the lower (15c) temp? 

Big thanks for that thought , much progress. Feeling good about this now. 

NOTE: I edited this earlier and somehow or other the first part of my post ended up in ‘your quote’ section. So last paragraph in the quote section, is actually the start of this note and response…phew.