The deed is done
And I am not talking about slaying a Scottish King to seize the throne!
We have had our heat pump going for three days! So, everyone should be thanking us for the more than clement weather we’ve been having.
Little note to the manufacturer: in normal operation, it is perfectly reasonable to prevent the heating circuits to be activated if the external temperature is above 20°C. There should be an over-ride while testing if the installation has been successful, however .
So you don’t know if it’s working?!
We have hot water being produced. Currently, feeding in 4.8kWh of electrical power is giving us 19.2kWh of heat to our hot water. Which means piping hot water for all our uses. A hot tank stores this for when we need it.
How do I know this? Well, the heat pump manufacture (Viessmann) have an app and you can see what’s happening:
We are not in Kansas any more, Toto! The hot water tank has a temperature gauge on it (seriously)… we set the temp to 50°C but we still have a solar diverter, so during midday, this free energy is heating our water to a little above that (I know I’m up late – I passed at least one kidney stone last night)…
![A temperature gauge showing 60°C and an immersion heater on a hot water tank.](https://samjwatkins.com/blog/wp-content/uploads/2024/07/QHuK5a424c2-1-e1721473330224-935x2024.jpg)
The sharp witted amongst you will notice that while the heat pump is heating to 50°C, the gauge is reading 60°C. Over the summer and sunny winter days, we use a solar diverter to heat an immersion heater and that goes above 50°C. As a type 1 diabetic, that should allow me to keep safe as well as scheduling a “hygiene session” once a week.
Looks like you’ve got what you need?
Well, we have been in training for this for the past couple of years with our Tado system. We never let the house get cold, and running with cooler water is efficient even with gas doing that, we only warm the rooms we need, when we need them using a timer.
Given the SPF (Seasonal performance Factor) for our system is good up to -5°C, we should be well catered for. We’re in the south of England, in a suburban area, so it will only be a few moments a year we go below that.
Of course, I will give you an update in January during the dead of winter. But at the moment, it all looks promising.
Here are the photos from the install:
![](https://samjwatkins.com/blog/wp-content/uploads/2024/07/QHuK5a424c0-2024x935.jpg)
![](https://samjwatkins.com/blog/wp-content/uploads/2024/07/QHuK5a424c4-2024x935.jpg)
![](https://samjwatkins.com/blog/wp-content/uploads/2024/07/QHuK5a424c1-2-2024x935.jpg)
![](https://samjwatkins.com/blog/wp-content/uploads/2024/07/QHuK5a424c3-1-2024x935.jpg)
Posted: July 20th, 2024 under 42, Driving off the grid.