Vaillant Arotherm Plus Air Source Heat Pump 2021 

Hi Alan, we do have a couple of videos on our channel with a full installation

Hi Simon, Thank you. It is all down to the refrigerant used, it has the ability to heat water at higher temperatures without the need to use a larger quantity of refrigerant and a larger compressor therefore enabling the heat pumps to work and comply for domestic uses etc. Of course the higher the temperature of the flow used for heating the less efficiency you get from the units themselves and I would always err on the side of caution with looking at heat pumps to supply these high temperatures. I hope that helps. Jason

@@dorewoodman thank you Jason. I’m building a passive house next year and been advised that we would need a 12kw system to accommodate four en-suite bathrooms and a the house overall will extend to almost 300m2. I’ve only ever had vaillant in my properties and would likely only ever use their kit however, I’m torn between this system and Viessmans Vitovalor, in essence a fuel cell which, although relies on natural gas, converts it to hydrogen and simultaneously, generates electricity. Do you install these?

@@skiiddy the Viessmann Vitovalor is certainly an interesting alternative. I think it comes down to a few variables; Will planning allow for effectively a fossil fuelled heating system? Is the area in which you are building the property "off grid" i.e no gas supply? Will a gas supply need to be installed to the property? With that in mind, comparative install costs? Do you wish to achieve a carbon zero house? What grants will be available etc? Which area of the country are you based Simon?

What size is the heat pump? Rads or UFH?

@@dorewoodman we have 30 meter squared of under heating in the lounge/kitchen/diner. Then 2 older lounges with 2 massive double connector rads about 12000 plus BTU. 3 bedroom on the first floor with large double convector rads then a 4th bedroom with electric under floor heating and a massive towel rad in the en-suite. The bedroom itself has a 6 foot tall decorative double rad.

Half of the downstairs is new build with all 150mm insulation in the floors and walls.

We have all brand new windows and doors and the loft conversion was only completed Feb this year so all to latest building regs. The only other thing we could do to the house is to dig all the concrete floors up downstairs in the 2 old lounges and hallway then insulate the floors and lay new slab. This wouldn’t be a viable option for us with expensive solid oak parquet flooring in these areas. Or maybe rip all the new glazing out for triple glazing.

Hi Glen, Thank you for your comment. A couple of points: The heat pump is usually set up with a 'Heat Curve' and uses its weather compensation components to determine the flow temperature. As the temperature outside increases, the flow temperature from the heat pump decreases and vice versa as outdoor temperatures fall. You should get 45 degree flow temperatures when the outdoor temps are cold enough to allow it, if that is how the design parameters are set up. In the summer the heat pump shouldn't be on at all for heating; if for any reason it was the flow temperature could be as low as 15-17 degrees. That said your heating system is not only determined by the flow temperatures but also the thermostat temperatures. If your thermostats for the UFH are set to 20 - 21 degrees and you have achieved these temperatures then there will be no need for the heating to be on at all, if that is the case and the pumps on the UFH manifolds are still running then it may be incorrectly installed/wired. I hope that helps.

@@dorewoodman thank you I think that explains it better I was just trying to test it and had set the temp to 24 but the pipes just didn’t seem to get any warmer so was really confused as to if it was working

@@glenphillips6634 You are welcome.

There are a number things that could be influencing that ... Is the outdoor sensor reading the outdoor temperature correctly? ..... which thermostat do you have controlling the heating? .... is it set up correctly under the settings? .... Do you have a buffer and are the thermistors positioned correctly? .... How many heating zones do you have?

@@dorewoodman thank you for your reply, I’ve found a fault logged re outdoor sensor so suspect it’s that.

Hi Z Alkhirsan, The cylinder to the left of the heat pump as you look at it is a Buffer Tank which can be in different capacities and the Hot Water Cylinder is to the right. The one in this video is a 45 litre buffer tank and a 250 litre cylinder for this particular installation. The Hot Water Cylinders can range from 150 to 300 litres typically but that is not to say for much larger properties 500 to 800 litre cylinders are available. Many thanks, Jason

@@dorewoodman thanks for that so both are needed

@@zalkhirsan9481 generally yes, with this particular heat pump.