ReedRichards

Use trellis with attractive climbing plant grown up it. Planted in it's own container if it cannot be planted in the ground: Blocks view of heat pump from AP2. Deflects some noise and muffles it when plant is in leaf. Blocks 10 cm projection of heat pump beyond end of wall. Provides attractive plant to view from Utility window. Cheaper option than complicated sound screen.

Yes, but it doesn't get overlooked by two windows, one of which looks out onto the garden. And it doesn't place the heat pump in a little sound-broadcasting enclosure.

You never said what was wrong with this idea:

Isn't it going to obstruct the door? Why not move it up and to the right (on the plan view). Or is that a bay window shown on the side elevation?

Not necessarily! Your system will have a design temperature, actually two - one for the UFH and one for the radiators, which will almost certainly be a higher temperature. If your radiators were sized so that they need to run at 50 C when it's -2 C outside and the calculation for this design was correct then that is what you need to do or the radiator-heated floor will be too cold. Of course, if your radiators had been sized so that they could run at 45 C when it's -2 C outside then should have given you a heating system with a better COP but maybe you didn't have room for radiators that large?

Can you not use a third party controller to split one of your zones into two?

This thread wasn't about zones. You might be better starting a new thread as people who have already read this one might not pay attention to a comment tacked on.

I have a long bungalow so I installed a recirculation loop for the hot water (possible because the pipes are in the loft). This costs money to run because the pipes circulating the hot water lose heat, no matter how well insulated. But it gives you near-instant hot water out of any tap on the loop.

Two choices when installing a heat pump, I think: You take the £5k grant which obliges you to use an MCS accredited installer who is obliged to make a heat loss calculation to size the heat pump. You forego the grant and don't use an MCS accredited installer but this might stop the heat pump being considered as a permitted development and you would have to apply for Planning Permission. I might be wrong here but if I am, I'm sure someone will jump in and correct me.

My LG heat pump describes its Weather Compensation feature as "AI". I think you may find that a lot of heat pump manufacturers do offer Weather Compensation but don't call it that.

My wife would short cycle between the "too hot" and "too cold".

That weighted average would seem to be very similar to the price of "regular" (not economy 7) electricity. Maybe you have an electric car so need the Economy 7 to charge that?

It looks like the item pictured when you follow the link above.

My tank was fitted with an independent safety cut-out. If this is tripped then, as far as I can tell, the diverter valve does not operate so the output water from the heat pump just passes through the buffer tank and back to the heat pump. You see the output and input water temperatures rise very rapidly until the heat pump cuts out. The DHW tank temperature does not change. You can still heat the DHW tank using the immersion heater when this independent cut-out is tripped.

Making sure the power is off, remove the thermostat cover by unscrewing the round-topped nut. You'll see a little dial temperature setting which controls the maximum temperature the thermostat will heat to. The immersion heater has its own thermostat which is at a different position in the tank to the temperature sensor used by the heat pump controller.

I have an LG Therma V with a newer (contemporary) controller but a box like the one in the picture. The box allows the heat pump to control the immersion heat but it is only used if I request the DHW to be hotter than 50 C. Since my target temperature is 50 C this only happens during the weekly Legionella cycle. My heat pump does not use an internal immersion-type heater, I'm not sure if it's not connected or not there. So when you ask about the heater in the heat pump I assume you want this to make the water in your tank hotter than 50 C, which the heat pump can achieve by itself without the need for supplementary heating.

Maybe sedum is the wrong choice for green? This is what worked in Norway: https://en.wikipedia.org/wiki/Sod_roof

Short cycling is the bête noire of boilers and heat pumps but it's not nearly so terrible as to lose 28 kW of electricity (so at least 28 kW of heat) to nowhere.

I have a hot water recirculation loop because I live in a bungalow and there are long pipe runs from the hot water cylinder in the centre of the bungalow to the bathrooms at one end and the kitchen at the other end. It's a bit of a luxury because the hot water in the pipes will lose heat no matter how well you insulate them. I run my recirculation pump for just 5 minutes every hour which means that the water out of the hot taps is immediately tepid at worst. To have a recirculation loop you need a tank of stored hot water. It makes no difference whatsoever how that hot water is heated so, if this is your issue, mention of an ASHP in the title is a complete red herring. To have a hot water recirculation loop you need both flow and return pipes for the hot water and a pump to circulate the hot water around the loop. It has to be a special pump that is WRAS certified for use with potable water. If your plumber did not install the return pipes then a retrofit would be very awkward. However the only adverse consequence is that you may face a long wait and have to run off a lot of cold water before your hot taps run hot.

If you have a pump but nowhere for it to pump to then turn it off (if it isn't off already).

Personally I would dig up that flat featureless lawn and make a flower bed with an evergreen shrub in front of the heat pump so it isn't visible unless you are right in front of it.

In my system I have a diverter (a WiFi-controlled switch) connected to my immersion heater and my heat pump connected in parallel to the immersion heater. Although this configuration seems to scare some people, it has never caused any problems. My heat pump has independent control of this immersion heater but would only use this control for an anti-Legionnaires cycle (which I don't bother with in summer because direct heating by the immersion heater is sufficient). Potentially my heat pump (LG Therma V) could sense when my immersion heater is being powered directly and if it knew the immersion heater was on without a request from the heat pump controller it might well show an error message - but that doesn't happen in my case.

If you have enough solar power to charge your battery it's probably not the middle of winter. Most of the rest of the time, my LG Therma V uses most power when heating the hot water. So when I have spare solar power I heat my hot water using the immersion heater (3kW). That's wasteful of energy but means that the electricity is all free, rather than topped-up from the mains.

Condensation is a potential bugbear; you don't want pools of water under each radiator. I'm not sure if radiators convect so effectively in reverse; I've seen it suggested that they don't.

Water pressure good enough? Does the shower require fine-tuning to get the right temperature? If you answered "no" to the first question and/or "yes" to the second than you have a case for getting an unvented cylinder.