Havenwise Review: My Experience with a Vaillant Heat Pump

Introduction

In this Havenwise review I’m looking at real-world use on my own system: what it does well, what it doesn’t, who it suits and who it probably isn’t right for.

I started using the Havenwise app at the tail end of the heating season last winter and I’ve now used it for a few months this winter, including a couple of very cold weeks in November 2025.

That’s long enough to see how it behaves day to day, how it handles changes in weather and what it offers over and above the standard manufacturer controls.

Below I’ll go through the areas that matter most in normal use, from flow temperature control and comfort to time-of-use tariffs and features of the app.

Table of contents

Use the Table of Contents below to jump straight to the section that matters most or scroll through at your own pace.

Who is Havenwise for?

If you’ve got zero interest in digging through heat pump menus or instruction booklets and just want your home to reach the temperature you set when you want it, with enough hot water when you need it, Havenwise looks to do that for you.

People on time of use tariffs, because Havenwise can automatically time heating and hot water for cheaper periods.

Anyone fed up with clunky manufacturer controls. The app gives you one place to see and adjust everything.

People who want steadier indoor temperatures. Havenwise constantly monitors room temperatures and outdoor conditions and makes adjustments on the fly.

Who is Havenwise not for?

If you’ve already tuned your system to the nth degree and squeezed every bit of performance out of it, Havenwise isn’t likely to push things further.

It’s primarily built for people who haven’t spent their life understanding heat curves, slopes and target flow temperatures.

Havenwise can’t polish a turd!

If there are fundamental issues with your system, like undersized pipework or poor flow rates, Havenwise is unlikely to fix such problems.

Yes, it can make better choices around flow temperatures, schedules and time of use tariffs, but it cannot fix wider issues with installations.

You would still need to consult with an experienced and knowledgeable installer about any physical or design/installation issues.

If you have a Vaillant Arotherm, you can always look at my Vaillant Arotherm Performance Tables & Interactive Widget article to see if your unit is performing as per the spec sheet.

How Havenwise works

Havenwise is a cloud-based optimiser for your heat pump. There’s no hardware to buy or install. If your heat pump is on their supported list and already connected to the internet, you’re ready to go.

It handles scheduling for both heating and hot water and works with many smart tariffs.

In the first few days of it running on your system it learns the heat loss characteristics of your house.  How quickly rooms heat up and cool down.  This allows it make better and more appropriate choices when it selecting how warm the water needs to be in the radiators or underfloor loops.

The aim is simple: run things efficiently and potentially cheaper without you having to watch over it.

You tell Havenwise when you want the house warm and when you need hot water, and it plans everything around that.

Setting schedules via the Havenwise app

There are separate screens in the app for heating and hot water schedules.

Here is a screen grab from the heating schedule screen.

In this example I have got a simple schedule of 08:00 to 22:00 set and this is replicated across all 7 days.

Although you can also specify different schedules for individual days.

No defined setback temperature

With many heat pump controllers, including the Vaillant, you get to choose a desired setback temperature.  I normally recommend this to only be 1-2 degrees below your main target temperature.

But in the Havenwise controller you don’t define a setback.  The app says that it automatically calculates the cheapest thing to do to meet your future schedules.

In reality on my system at least, I’ve found that it drops the system back around 1C from main target, which is perfect.

Hot water schedules

The hot water scheduling screen in the app is a very similar format.  You specify the time you want hot water for and the temperature (setpoint) target.

Again, being able to have the same schedule across all days or choose individual daily schedules.

How Havenwise works with time of use tariffs

Time-of-use tariffs are where Havenwise has the upper hand over manufacturers controls.

Once you enter your tariff details, it looks to shift heating and hot water into the cheaper periods and avoids the expensive ones unless it has to.

If you’ve read my guide to the best heat pump tariffs, you’ll know how wide the gap can be between off-peak and peak rates. Automating this adds up.

Here’s how Havenwise behaves with popular Octopus tariffs:

• Agile
  Havenwise can make use of the cheapest half-hour slots without you checking the price graph every day. Agile swings a lot, so automation helps.

• Cosy
  Cosy offers three cheap windows each day. Havenwise loads heat and hot water into those, then eases off during the more expensive hours.

• Intelligent Go
  The long cheap overnight block is simple for Havenwise to work with. It can pre-heat the home before the morning peak, which suits houses that hold heat well.

Havenwise automates in the background so you don’t have to micro manage the system and schedules.

You can switch on and off “tariff optimisation” for both heating and hot water individually.   If you turn the settings off Havenwise will prioritise efficiency and steady indoor temperatures.  Which is what I have been doing.

If you are considering switching to Octopus Energy, use my referral link where you can claim £50 of free credit upon switching.  Thank you if you decide to do that.

Get performance stats from the Havenwise app

The Havenwise app looks to be a one-stop shop for all the information about your heat pump.

• Running costs
• Energy usage
• Performance metrics

Because you’ve told it what tariff you’re on, it’s able to calculate the daily running cost of the heat pump.

It can also pull energy usage data from the heat pump to provide performance metrics as you can see from this screen grab.

Obviously, if you have solar and/or batteries, it won’t know about those.  So your daily totals might be a little off, like mine.

Caution: manufacturers onboard monitoring have a reputation for not always being the most accurate.  So i’d take the numbers from Havenwise with a pinch of salt as these are only being pulled directly from that heat pump.

For the most accurate monitoring figures, always consider an Open Energy Monitoring setup with separate billing grade heat meter and electricity meter.

If you have a Vaillant Arotherm heat pump I go into detail in this article showing the various ways you can get COP and SCOP from your heat pump; How to Measure Vaillant Arotherm COP.

Before you try Havenwise: write down your existing settings

One thing I’d recommend, is to save your current settings before linking your heat pump to Havenwise. If you decide to switch back to manufacturers control, you’ll want these.

At minimum, take note of:

• Your weather compensation curve

• Minimum and maximum flow temperatures

• Room influence settings (if you use them)

• Setback temperatures

• Heating and hot water schedules

• Any installer-level tweaks you’ve made

On a Vaillant system Havenwise drops the curve to 0.1 and adjusts the minimum flow temperature, so if you disable it without restoring your old numbers, the system may behave oddly.

This is a common issue that has been reported in Reddit and Facebook threads as people switch Havenwise off and can’t remember what they had before.

If you have Vaillant Arotherm I have both Heating Basic Settings and Hot Water Basic Settings guides if you’re struggling with where all the settings are.

My heat pump background

I’ve been monitoring, adjusting and logging my 5 kW Vaillant aroTHERM since it was installed in October 2022.

I’ve written plenty of guides explaining how the Vaillant logic works, and I think I’ve already tuned my system to its limits using the standard controls.

There’s now over 3 years of my usage data up on Open Energy Monitor and my heat pump is part of heatpumpmonitor.org along with hundreds of other monitored heat pumps.

So I’m probably the worst person to test an automatic optimiser. What else could Havenwise do with a system I’d already fine-tuned?

Where my thermostat is located can be a challenge

My sensocomfort controller is on the wall in the dining room.  On a Vaillant system, the sensocomfort is the combined controller and thermostat that reads the internal temperature and serves as the reference point for the rest of the house.

Our dining room is a single storey extension at the back of the house on the north side.  But it’s also almost open plan into the kitchen (part of the original house).

So if there are people in the house and we are coooking etc, then we get extra heat from these sources, which the sensocomfort reads.

On the flip side, when there’s no one in the house, no bodies, no cooking and no solar gain, the dining room needs more heat because it’s single storey, there’s 3 sides and a roof exposed to the world.

This was always a challenge for the Vaillant controls as sometime there could be more heat than needing (cooking / people etc) and then the next day not enough (empty house etc).

Why Havenwise can feel better than the standard controls

Vaillant’s controls have a good reputation with installers as one of the best out there.  I’ve always rated them on my install, but they’re not perfect as I mentioned in the section above.

Two things have always bothered me:

• They aren’t aggressive enough when the house is well below target temperature (or indeed above target).

• The weather compensation curve is never perfect for all conditions.

Let’s look at both.

They aren’t aggressive enough

If the room is a few degrees below target, the Vaillant controller won’t raise the flow temperature enough to close the gap quickly. Even in “active” Room Temp Mod mode it only adds a small nudge to the target flow temperature.

This means room recovery after a setback or hot water cycle can take hours. It’s why I often tell people not to use large setbacks (1 to 2 degrees maximum)

Similarly, if the room is above target, the Vaillant controller won’t drastically drop the flow temperature to reduce the amount of heat coming from the heat pump.  Again, only a small amount if you’re in “active” Room Temp Mod mode.

Havenwise takes a more aggressive approach

Havenwise has no hesitation in raising (or dropping) the flow temperature to match the gap.

That can be great to get the room back up to temperature, but it can also backfire. If a back door is left open and the room drops, Havenwise reacts hard, sometimes choosing as high a flow temp as it possible.  When it gets to the point where you can ‘feel’ the heat from the radiators, then you know it’s gone a bit too far.

I ended up working with their support team to cap the maximum flow temperature on my installation to stop moments where it gets a bit too enthusiastic.

Higher flow temperatures will cost you some efficiency, but sometimes you want the room to get to target quickly. So there’s a balance to be struck.

It’s almost like there were three levels of aggression

1. None to Low: Vaillant Standard Controls
2. Medium: Havenwise with the maximum flow temperature limit
3. High: Havenwise originally out of the box

As Havenwise are constantly collecting user feedback and experiences, perhaps the high aggression default isn’t there anymore.  But if it is, it’s good to know there is a simple fix that can be put in place.

The bottom line though is that Havenwise chooses the right flow temperature way more often than the Vaillant controls did.  If the room is over target, it chooses a lower flow temp.  If the room is below target it looks to choose a higher flow temperature.  Using more inputs than simply picking a flow temperature off a predetermined weather compensation chart.

Aggressive weather compensation does have pitfalls

The Christmas period of 2025 did highlight a few minor downsides to the more aggressive weather compensation that Havenwise can apply.

As with most control systems, it really depends on where your thermostat is located. As mentioned earlier, ours is in the dining room, which is almost open plan with the kitchen.

The following scenarios caused a few issues:

• Cooking
• People being in the house
• Everyone spending long periods together downstairs

All of these generate extra heat. Cooking, body heat and general activity meant the thermostat saw the room as overheating. To counter this, Havenwise kept choosing lower and lower flow temperatures to maintain a lower effective room temperature.

In one sense this worked perfectly. The dining room didn’t continue to overheat and the heat pump efficiency increased with lower flow temperatures.

But there was a downside.

Because the chosen flow temperature was based on keeping the downstairs comfortable, the same water circulating upstairs wasn’t quite enough to keep the bedrooms at their target temperature. The upstairs cooled slightly as a result.

We’re only talking about around 1 °C, so nothing drastic, but it’s a scenario worth being aware of.

The key takeaway is to think carefully about where your thermostat is located and remember that the flow temperature it drives applies to the whole house, not just the room it’s in.

The Vaillant curve is never perfect

After three winters I’ve accepted that the Vaillant curve is always either slightly too low or slightly too high, depending on the outdoor temperature.

You can set it perfect for mild weather, only to tweak it again when the first cold spell arrives.

I always found myself bouncing between curve settings (around 0.4, 0.45 and 0.5) when the outdoor temperature is above or below the 4 to 5 degree mark.

And there were windy days, then my 1930’s house seemed to need more heat too.

So just like the previous point, Havenwise does a much better job of this.

Because it’s constantly scanning indoor temperature, outdoor temperature and other external factors it makes better choices without the user having to intervene.

How Havenwise controls a Vaillant heat pump

On a Vaillant, Havenwise takes control in a slightly unusual way. The first thing it does is drop your weather compensation curve to 0.1 and leave it there. That effectively disables the normal curve logic because Havenwise isn’t relying on it.

Vaillant doesn’t let you set a “target flow temperature” directly. The target flow on these units is always the outcome of other parameters, usually the curve and the outdoor temperature. Havenwise gets around this by using the minimum flow temperature setting instead. By raising or lowering the minimum flow temp, it can push the heat pump to run at the temperature it wants at any given time.

How Havenwise selects the target flow on other supported brands is something I don’t know, but they’ve clearly worked out a method for each model they integrate with.

One important Vaillant-specific note:

The energy integral (degree minutes) counter still applies exactly as normal.  Havenwise doesn’t bypass it.

I covered how this works in a separate Energy Integral article.

So on a Vaillant system, Havenwise’s real control lever is the minimum flow temperature. That’s what it uses to decide how hot the water going into the radiators or underfloor needs to be to reach your target room temperature at the right time.

Havenwise in action

Because my heat pump system is constantly being monitored by the Open Energy Monitor combination of a heat meter and billing grade electricity meter I can see what’s going on under the hood.

Here is an example of a very cold day in November 2025 where Havenwise was in control of the heating.

Our daily schedule on this day was:

• 7am to 10pm: 20C

And that’s it.

With our hot water to run at 1am and 1pm.

Here is a trace from Open Energy Monitor to a 15 hour period.

• Minimum Outside: -2.3C
• Average Outside: -0.3C
• Maximum Outside: 2.9C

Direct link to the monitoring period here: https://emoncms.org/energystatsuk?mode=power&start=1764094530&end=1764150000

If you’ve ever looked a Open Energy Monitor trace of a Vaillant system you’re probably used to seeing very constant flow temperature and smooth lines come out of an Arotherm.

Because Havenwise is making more on the fly choices, you get a slightly more erratic view in the monitoring.

• 1st Green Arrow: maintaining 20C
• Blue Arrow: maintain a setback (usually around 19C)
• Big Spike: hot water run
• Orange Arrow: the build coming out of the hot water run to target temperature for morning breakfast
• 2nd Green Arrow: back to maintaining once target it reached

You can see that Havenwise has no problems throwing hotter flow temperatures into the heating system to ensure you reach your target.

Aggressive weather compensation does have pitfalls

The Christmas period of 2025 did bring some minor downsides to the aggressive weather compensation that Havenwise can provide.

It all depends on where your thermostat is located really. As I said earlier, ours in the dining room with is open plan to the kitchen.

The following scenarios gave us a few issues

• Cooking
• People
• All in one room downstairs for long periods

Because all these activities generated heat. People, cooking etc, then the thermostat on the wall noted this and saw the room overheating.  To counter this, Havenwise kept choosing lower and lower flow temperatures to maintain a much lower room target.

This was fantastic in a way as it meant the room didn’t overheat further and it also meant the performance from the heat pump was good.

But this did come with a downside: the upstairs became cooler.

Because the target flow temperature chosen was to maintain the warm downstairs, the same water in the radiators upstairs wasn’t enough to keep the bedrooms to the target temperature.

Now we are only talking 1 °C or something.  Nothing drastically bad.  But this scenario is something to be aware of.

Consider where your thermostat is located and remember that the whole house flow temperature is dictated by it.

Hot water control

I haven’t used Havenwise for hot water because I run a Mixergy cylinder with its own logic. Thankfully you can hand over heating, hot water or both to Havenwise, depending on your setup.

From my own “golden rules” investigation work on hot water, running cylinders during cheaper off-peak windows is one of the most effective changes you can make. It beats chasing a tiny boost in COP every time. If you’re using a standard cylinder, letting Havenwise schedule it automatically makes a lot of sense.

I already do this, so didn’t need Havenwise to do that for me.

Havenwise is software based, so expect updates

One of the main problems with a lot of heat pumps is the software version on them is fixed, as I found out on my Vaillant Arotherm.

I discovered a bug on the particular firmware that I was running that caused the unit to cycle more than it should.  I was horrified to find out the only way to upgrade the software running on the heat pump was to replace the circuit board.

The whole saga was explained in the article:

Vaillant Arotherm Firmware 351.06.07 Problems (Energy Integral)

The good news with Havenwise is that because it’s cloud/internet based, the software can be upgraded whenever they want.  So expect improvements and bug fixes over time.

Social media questions answered

I had a search around various social media platforms looking for commonly asked questions about Havenwise.

Here’s a selection of them with my own thoughts.

Does it save money?

In my case, I doubt it’s saved me much through my time so far. I already schedule my hot water in off-peak periods using the Mixergy app, and I also run solar and batteries. As I’ve said, I’m probably the worst person to trial this if you’re looking for big financial gains.

That said, Havenwise does seem to make smarter choices with flow temperatures compared to the fixed values you get from standard weather compensation. I’ve seen the COP look better at certain points in the day, but it’s anecdotal rather than anything I can evidence so far.

And as stated in my Golden Rules for hot water, if you can let Havenwise automatically move your hot water into cheaper periods of time of use tariffs then there should be savings to be had.

Most of the benefit for us has been comfort. The house holds its target temperature more consistently and recovers faster after setbacks or hot water runs. The overall feel of our house has improved.

Is it compatible with my heat pump?

Havenwise only works with certain internet-connected heat pumps, but the list is growing. Rather than me trying to keep a manual list here, it’s easier to check their official compatibility page:

Which heat pumps are Havenwise compatible with?

If your model is on that page and already online, you’re likely good to go.

Is setup complicated?

Havenwise has a full setup guide on their site, so it’s easiest to follow that:

Setting up Havenwise

In my case it was very straightforward. During the onboarding process I just connected my existing Vaillant login to Havenwise and granted permission for it to talk to the Vaillant system. That was it. After that, everything appeared in the Havenwise app within a few minutes.

Does it make the house too cold chasing cheap rates?

Personally, I’m not a fan of pre-warming the house during cheap periods and then letting it cool when prices rise.

One of the best things about running a heat pump with steady weather-compensated control is the comfort. It feels odd to give that up just to save a few pence here and there.

Because of that, I haven’t tested the aggressive pre-heat approach myself. But if you do want to try it, Havenwise has far more logic behind its decisions than the standard manufacturer controls, so it’s probably better suited to the job.

For me, cheap rates are far more useful for hot water and home batteries. Hot water in particular is a clear win, which is exactly what I covered in my Golden Rules hot water guide.

Heating the house is where comfort matters most, and I’m not keen on trading that away.

You can switch on and off “tariff optimisation” for both heating and hot water individually.   If you turn the settings off Havenwise will prioritise efficiency and steady indoor temperatures.  Which is what I have been doing.

Does it reduce cycling?

Cycling happens when the minimum heat output of the unit is higher than the heat the house actually needs at that moment. It’s a normal behaviour on many systems and depends more on your emitters, insulation and heat loss than the controller you’re using.

I’ve covered all things cycling  properly here (Heat Pump Cycling and Minimum Modulation), including a calculator so you can work out when cycling should happen on your setup.

Havenwise doesn’t magically remove cycling, I’m not sure it could?

Does it play nicely with weather compensation?

Havenwise is weather compensation, just a more advanced version of it.  Think of it as Weather Compensation on Steroids.

Standard manufacturer controls look at the outside temperature and pick a flow temperature from a preset table, sometimes with a bit of room influence added on top.

I explained how Vaillant Weather Compensation works in a dedicated article along with charts and tables.

Havenwise goes further. It uses more inputs, including how fast your house loses heat, recent behaviour and upcoming weather. That lets it make smarter and more flexible choices than a fixed curve can.

Once Havenwise is in charge, it effectively takes over the flow temperature decisions. The heat pump’s own weather comp is still there in the background, but Havenwise is the one making the decisions.

Will it help with defrosts?

Defrosts are physics. When it’s cold and humid, any heat pump will build frost on the outdoor coil and clear it with a defrost cycle. There’s no controller that can stop that from happening.

I took a proper look at why defrosts happen in this article: Heat Pump Defrosts.

Most things that influence defrost performance aren’t controlled by weather compensation or Havenwise. They’re usually tied to airflow, coil design, refrigerant temperatures and outdoor conditions.

Havenwise might help the system recover and get room temperatures faster afterwards by choosing sensible flow temperatures, but it won’t reduce how often defrosts occur.

How reliable is the Havenwise app?

I’ve had no issues with it. The app is fairly basic at the moment and could use a few extra controls, like a simple boost or heating pause option.

Even so, it has already gained a couple of improvements in the time I’ve been using it, so I’m confident more features will land as the product matures.

What about customer support?

My experience has been good. I’ve used their WhatsApp support a few times and the replies have always come back quickly. No problems so far.

Havenwise help centre

I only covered a few questions and answers here, but Havenwise have a comprehensive help centre with a whole host of questions and answers.

https://help.havenwise.co.uk/en/

Havenwise summary and recommendation

As I said earlier, my system was already well tuned before I started trialling Havenwise, so I’m not the ideal person to see instant improvements. I know the small quirks in the Vaillant logic and I monitor my system every minute of the day, so I was hoping Havenwise could smooth out those niggles.

And the reality is that it did. Havenwise does a better job, in my view, of choosing the right flow temperature to hold the indoor temperature steady no matter what combination of conditions it’s dealing with, whether that’s current indoor temperature, target temperature or the weather outside.

It also ticks the box of being more aggressive when the house is too far away from the target temperature. As I explained earlier, it was sometimes a bit too aggressive, but Havenwise added a small fix that sorted that. It also chooses lower flow temperatures when the indoor temperature is slightly above target, which was good to see.

I can’t vouch for the hot water side because I didn’t hand that over, but if it applies the same logic to picking the cheapest slots on your tariff and matching that with when you want hot water, then it should work well. Moving hot water to off-peak periods is one of the easiest wins you can make.

So should you give Havenwise a go?

• If you’ve no interest in learning the inner workings of your heat pump and just want the house to be at the temperature you set, and have hot water when you need it, then yes, it’s worth trying.

• If you’ve no time to watch your time-of-use tariff and want the cheaper slots handled automatically, then yes, give it a go.

• If you’ve already tuned your system but you’re frustrated by the limits of a fixed curve and want steadier indoor temperatures, then yes, it’s worth a look.

• Vaillant has really good intuitive controls but the same cannot always be said for other manufacturers.  So if you are frustrated with the controls of your heat pump then you may want to consider letting Havenwise take control.

The good thing is Havenwise offers a free trial, so you can test it and walk away if it’s not doing what you want. Just make sure you note down your existing settings before you start.

If you do decide to take up the free trial, you can use my referral code as this helps support the website:

https://www.havenwise.co.uk/partners/energy-stats

Note: I have not been paid for this review.  These are my own thoughts and observations from real world lived experience with it.