Hi ​@SilentMelodies I have had a Daikin heat pump for 3.5 years and have read loads about it but am by no means an expert ! That said, here’s my suggestion on what you could do:

Stop using the log burner, lovely as they are they do chuck out particulates which are harmful to breath in, especially with the baby in mind. 

Open all trvs and try running the system 24/7. Let it settle over a day or two. 
 

The flow temperature of 49 is high; my flow temp only reaches 45 (all radiators).

Weather compensation is definitely the way to go. I think the Ecodan can be set up to do this automatically but that’s where my lack of knowledge of your controls lets me down !!  
We need the help of someone who has one… ​@M.isterW ?

Re hot water: if you’re on a tariff with cheap overnight electricity then running it in the small hours when you won’t miss the heating is the best option. The hp doesn’t do both at the same time.

Another thing I’d highly recommend is to look on the HeekGeek’s website and see if there’s a heating engineer with Heet geek's guarantee that covered your area. If you can get them to check over the system it would be money well spent. 
Can you post a photo of the back of your outside unit showing the pipe work and one of two of the inside pipe work. That’s a guide to how well it was installed.

Hi.

As Julia has already said, 49 degrees is too high a temp. The heat pump won't run efficiently at that temperature and unless it's really cold outside you shouldn't need a flow temperature that high.

With an Ecodan you have an option other than weather compensation. It's called Auto Adapt (it's probably best to Google it for more info) and it uses a temperature sensor in the house to help run the system at the lowest flow temperature. The FTC can be used as the temp sensor, if it's located in the house. Or you can buy a Mitsubishi wireless sensor.

Having your system zoned and controlled by TRVs will be messing up your efficiency. Remember that with a heat pump not every unit of heat costs the same. It can be better to have rooms warmer even if they aren't being used if that results in better system efficiency. Heat Geek on YouTube have some great videos about the problems you can cause by zoning a heat pump system. I see that Julia has already recommended them - great minds

Initially I would go with Julia's suggestion and open all the TRVs. I'd set the system to weather compensation and get the flow temperature to a level that keeps the house warm enough. I would then look at a Mitsubishi wireless controller and switch over to Auto Adapt.

If you find some rooms are overheating while others are at the right temp you can then turn down the TRV, but only in that room. Don't go round the house tweaking all the TRVs. Only do it as an exception.

When you've got the system stable and working at different outside temperatures (which should result in different flow temperatures) live with it for a while. If you find that you've still got rooms overheating or under heating you might need to change some rads.

As for hot water... again, do what Julia says

Ours is on a timer, twice a day. Ours used to reheat when the tank temperature dropped but we found that it shut off the heating at inconvenient times. Now it runs early in the morning and mid afternoon, when we don't need the heating.

There are YouTube videos that show how to change the settings on the FTC.

​@SilentMelodies  have these suggestions been any help to you ? It would be useful to know….

So I think I was hit with a bit of analysis paralysis and panic when I saw the max flow temp at >15 degrees being 35 and then realised two things:

1. At the moment it’s freeeeeezing outside. 35 degree flow temp only happens above 15 degrees outside temp so it’s likely to be closer to what I have now.
2. Incrementally reducing the fixed flow rate to match roughly where it would sit on the compensation curve and then switching it over is an option to test it.

In the end I switched Friday morning to compensation curve with quite a wide curve (45 flow at 0 degrees  and below outside and 35 degrees flow at 15 and over outside). Timed the DHW to kick in and reheat twice a day (2pm - 3.30pm and 2am - 3.30am). 

Need to run it a few days to see if it’s made a difference to energy consumption and/or heat but I’ve noticed in the temperature sensors scattered everywhere the house has been more consistent with keeping a temperature rather than cycling/bouncing around. Again, not ideal testing parameters cause it’s only been 24-28 hours.

I’ve decided to keep the TRVs on their own schedule at the moment and tweak them moving forward.

Regarding the log burner - I have an air quality monitor and regularly review it so we’re aware if it is/isn’t acceptable but thank you for noting it.

I think the biggest issue I had here was not wanting to knock the heating out for several days while testing and because any incremental change may take days to reap rewards/realise it’s wrong - it was holding me back.

Thanks for the advice.

That all sounds very positive. I know what you mean about altering settings, I was nervous to changing mine (still am really‍♀️) but mine was set up really badly to begin with so had to be altered.

Glad to hear you can monitor the log burner too .  
One last thing, assuming your radiators are correctly sized the system will run at its best and most efficient with all the tvrs open, let the controller do all the work.

Good luck with it all, keep us posted as it’s all useful info.

I’ve just seen this from Paul Spence who runs the Heat Pumps UK Facebook group: 

“ if a system is designed properly , commissioned properly, you don’t actually need a thermostat at all.. temperature limiting for solar gain but no thermostat.. If an emitter is sized to deliver the heat loss, the correct dt across the emitters, the system is in essence controlled via return water temperature and pure weather compensation control. “

So from the expert !! TRVs being Thermostatic Radiator Valves of course - this comes from a discussion about “third party controls” which are in most cases unnecessary. 

​@SilentMelodies …sorry, a bit more to add to this (from Nathan Gambling - heating engineer and podcaster - on the same topic):

 A heat source can tell if it is over supplying heat or under supplying heat by monitoring its own F&R temps - that’s the Flow and Return ie the water flowing out of the heating device and then returning into the device. TRVs would in effect ‘strangle’ the flow and b**ger up the return temperature. At least, that’s how I see it. Best to keep it simple.

Also, having just been for a walk around the block here, the air is full of smoke from people’s fires and no doubt log burners. So maybe their air quality indoors is okay but it isn’t outside ! Nothing personal.

Appreciate it, but we live ourselves in the middle of nowhere so the only people we’re affecting is ourselves . Everyone’s situation is different and didn’t want to to go into that level of detail since it wasn’t relevant to the question.

At the moment, things are running well and big changes aren’t something I want to implement - slow and steady works for us. I’ll start unthrottling the TRVs fully after testing has shown decent results. At the moment, we’re not cold and not spending 90kwh / day so any further improvements are a bonus.

Sorry - just having a bit of a vent (!). You’re lucky. It’s really noticeable here, since gas prices went up, that people in our suburban neighbourhood are using their fires more. Smoky fumes every evening even when it’s not especially cold. And don’t get me started on bonfires…

And to cap it all another beautiful street oak tree has been cut down to a miserable limbless stump this week  

Moan over.

They might be an expert, but they don’t know exactly how our house is constructed (insulation, vents, zones, etc). As I mentioned, the original installers are refusing to give any documentation that would give us an indication of heat loss, DT, etc throughout the house. Hence asking here for a bit of reassurance before making the switch.

Appreciate that, but I didn’t ask for advice on my log burner. It was a minor point of a larger question and I’m kind of fed up of people making massive assumptions about how we live without understanding the bigger picture (which is, again, irrelevant to the question). Would be worth not assuming everyone lives in a built up area and has a log burner for aesthetic reasons. Moan somewhere else please.

There’s no difference just now between thermostat controlling TRV open/closed and setting the TRVs to a static temp (as the TRV when it hits a temp will auto close and the thermostat monitors the full room and closes when it hits a temp). The only way to “balance” those rooms is via the lockshield valves but that’s not required here.

Well that’s told me. I’ll keep my trap shut in future then. 

Just a heads up. Please remember that Julia is a trusted Forum Volunteer just like I am and it’s OK for her to share her thoughts just like everyone else can. They are just her thoughts and it doesn’t mean you have to agree with them, but please try to see it from her side too.

I’m in the Fire Service myself as a Community Volunteer and I can tell you that log burners are a nightmare for the Service because so many folks don’t look after them properly. We don’t stop people using them, but we do have to keep giving out the same advice constantly because of the risks of a mis-managed log burner. The statistics speak for themselves…

Despite that, the Service isn’t calling for log burners to be banned - just for people to use them properly!

You don’t have to accept our advice - whether you do or not is entirely at your sole discretion - but please allow us to offer it because others may find it useful anyway. The Forum Volunteers are highly experienced and we often use our own experiences as part of our advice. You may - in some cases - find it useful to experiment with our recommendations, even if it’s at least just for a few days.

You’re right - it’s okay for someone to share their opinion but:

1. Sharing it multiple times starts to become preachy, especially when asked to move on.
2. I don’t need to listen to it.
3. Getting upset because someone disagrees with said opinion is just childish.

This is an internet forum. it doesn’t matter how long someone’s been here, how “senior” they are – doesn’t give them carte blanche to dish out unsolicited opinions and get away with being annoyed about it when pushed back on.

Your advice was good about other stuff btw, but the log burner stuff wasn’t relevant and just diverted attention away from the main question. Getting upset because this is the third time I’ve mentioned it’s not relevant is just a bit silly.

Ultimately, this all doesn’t matter. For anyone reading this in future from Google/similar here’s what I’ve changed:

• DHW now comes on 2x per day on ECO (2am - 3.30am and 2pm - 3.30pm)
• Legionella goes to 60 degrees every 15 days
• Heating is set to compensation curve with high flow being 45 degrees at -1 and below and low point being 15 at 35 degrees.

I’ve seen a massive change in usage so am happy and the house is consistently warm. Even with the log burner.

So you’ve called me preachy, upset, childish, and annoyed. Thanks for that.

I’ve passed on information here about TVRs, which comes from genuine expert heat pump installers, that they are best left open or not installed at all. I’m suggesting your system will run more efficiently if you take their advice. 

No worries!