My DIY installed Vaillant AroTherm Plus is now LIVE

When I asked Midsummer recently for an AroTherm for a friend,they said that they were going to get them into Ireland.

I only say that since the 5kW unit can do over 7kW.

You'd need to look at other units specs to see what they can actually produce, but I wouldn't be keen on oversizing at all, as you'll have cycling in milder weather.

If you look at the link to my data, you will see that while I am running continuously, I am very much running on unit minimum now a lot of the time during the mid afternoon.

My thoughts a year ago was, if I need to use a fan heater to top up a room 10 days of the year, then so be it. We didn't need to, as it generated enough heat

Totally. Remember that the larger the unit, the higher the minimum, which can lead to increased cycling, which therefore increases consumption and reduces efficiency

I've really no idea tbh. But sounds like the minimum is always high, irrespective of what is needed or not

DIY is very do-able, especially changing from an oil boiler, as the pipes will very likely be outdoors already, and just need extending.

Of course, the indoor pipes can be an issue, as can the emitter sizes

A temperature sensor should be fine over Cat5. With the Vaillant, it had an ebus wire which HAD to be 0.75mm².

Re-read the instructions for whatever unit you bought, as you may only need the temperature wire to the Controller, and not the outdoor unit.

However, irrespective, I would add a 1" flexible pipe into the trench with a pull chord, for running anything else. In fact, I would run two - one spare.

Will you drop the armoured AC into this trench too ?