New build. Daikin heat pump Altherma 4 advice please.

Hi ​@Aloha , ours isn’t a new build but we did have a Daikin ASHP fittted earlier this year.

What I’ve noticed with all the various notes from people is that each property and family needs are different so don’t be surprised if you end up with some adjustments just for you.

We have a slightly smaller hot water tank and ours is heated to 47 degrees C early morning, ready for showers (4 adults). Our water remains hot enough for most other usage during the day but we have another heating time mid afternoon which tops up to 40 degrees if needed (no reheat, just two scheduled slots).

The eco and comfort settings are simply preset temperature levels so that you can easily choose which you need and when.

You can set different timings for each day and so you might find that your weekends are rather different to weekdays.

For heating, we only setback to 19 degrees overnight so that the heat pump doesn’t need to work overtime in the morning to get the fabric of the property back up to temperature.

Of course, one other thing to consider is your tariff. Our tariff gives lower cost electricity early morning, early afternoon and late evening so your prime usage times of 6 to 8 pm might mean that you need to prepare before and avoid reheat during that time as it can be charged at peak rates.

I'm sure you’ll find your ideal set up after trying a few things before too long.

There are several who use the forum who have had their heat pump longer than I have so they may be able to comment as well.

Thank you for your help.

we mainly all have our showers etc after 7pm so ours would kind of be opposite to your settings.

so if I put a setting of say on at 6am, can I then set it to off at 7am? Donut won’t come on even if the tank goes cold? 
im just trying to work the best way to do it so I don’t have reheat on 24/7

Yes, I presumed that from your post 

This is my hot water schedule for today .. 

Your time slots would be different but you can set a time for heating and a time off (not heating). Our second slot in the afternoon uses the eco level so only heats if the temperature has fallen below that level … a sort of ‘controlled’ re-heat.

​@Aloha a couple of questions: what tariff are you on and do you have solar panels?

I've read that heating the tank from cold is the most efficient as far as the heat pump is concerned (discussion on OpenEnergyMonitor forum). So if you’re happy to do a bit of experimenting you could set it to a schedule to heat up during the day, particularly if no one is at home. That would mean the outside temperature should be warmer and the hp has less work to do. You could raise your target temperature a bit, eg 48 deg, and see if it lasts the evening.
You mentioned set back, which is usually a term for lowering the overnight room heating target temperature. Did you mean the Reheat Hysteresis ? That is 10 deg by default, so if your reheat temp is 45 the hp will operate when the tank temperature goes below 45-10 ie 35 deg.

You could keep those values and set the system to “schedule and reheat” then see if the reheat kicks in after all those showers. My reheat starts if I have a long shower for a hair wash. However the reheat is set at 40 deg. 
It’s all trial and error to see what works best for your household. Good luck !!

One more thing to consider once room heating is needed: the heat pump cannot do both hot water and room heating at the same time. 

Ah yes - I hadn’t considered the hysteresis level on hot water as I don’t use reheat 😬

Thank you. Yes that’s what I meant.  I didn’t know how to spell it haha. 
thank you for you great advice 

Nor did I but thankfully the phone did !!

So without sound too silly.

if I set it to come on at 5pm till 8pm at 45c on schedule and reheat, then off all night till 6am the next day till 8am at 45c it would be more efficient than reheat only at 45c ? 
as a family we tend to have showers etc in the evening after 7 ish.

just trying to find if it’s better for me to do that schedule or leave it as it is at 46c reheat. 
we have a fixed rate tariff currently, so it doesn’t matter what time of day 
 

Thank you so much for your advice.

So just to clarify.

I set my reheat to 40c

Set comfort to 48c

Set eco to 45c.

Then program  schedule for hot water on at 3pm on comfort till 8pm then off.

Then programme eco to come on at 3am and then off at 8am.

Does that sound right? 

That way it won’t be one all day then? 

Or do I leave it on 24/7 and just put the two schedule times in? 

That’s the bit where I get a bit confused. do I put a stop setting in between those two times? 

So you’re saying that I don’t need to set a stop time? 

Just a schedule to come on at comfort setting at 3pm and then and eco setting at 3am? 

You have been so helpful to me 

I’d say yes to those settings, having selected “Schedule and Reheat”

Unless there’s something different about Altherma 4 !! Mine’s an Altherma 3 and it doesn’t need the Stop.

Try those settings and temps, and keep an eye out for it coming on to do a reheat after all the showers. You will find it helpful to see how long it takes to heat the tank during the scheduled times (if you look on your Usage graph from your electricity meter - assuming it’s a smart meter of course, you won’t have to get up at 3 in the morning).

Please report back and let me know how it goes. 

Julia

Thank you so much.

I’ve  now put a schedule and reheat on.

3pm comfort 48c

3am eco 45c

Reheat 40c 

I may introduce a further setting Like turning off the hot water at 8 pm and then have it coming back on again at 3 am for the eco-setting. 
As you say, it’s experimenting to see which works best. At the end of the day, I don’t want it to cycle on and off all day when it’s not being used. I mean, hot water usage is after 6 pm at night and a tiny little bit in the morning the next day

Morning ​@Aloha and a warm welcome to the OVO Forum.

I hope you’re well and had a good weekend. I’ve added the Heat Pump badge to your Forum account so that other members can recognise the kit you have. Thanks for your great post - I’m really happy to see you’ve received some helpful answers here.

​@BPLightlog / ​@juliamc thanks as always for your valuable insights 🤝.

​@Aloha you might also find some useful information in this previous research piece:

There’s also some handy info on the Daikin page here: https://www.daikin.ie/en_gb/knowledge-center/7-tips-to-make-sure-your-heat-pump-is-running-100--efficiently.html

Keep us updated as to how you get on - we’d appreciate it. Cheers!

Hey ​@Aloha, 

I just wanted to check in and see how everything is going with the new schedule. Have you seen any improvements? 

I bet Julia and BP would love to hear how their advice has made a difference! 😊