JohnMo

I think you are confusing yourself. Trickle vents, just add humidity activated trickle vents to dry rooms (close wet room ones); they look after themselves. In wet rooms and kitchen just add dMEV fans (such as Greenwood with automatic boost for humidity) set to required min flow rate. Job done.

The normal for an unvented cylinder is cold goes to UVC, and is then taken to cold consumers at the same pressure as the cylinder from an output at the pressure control valve. My UVC was a retrofit, so the incomer into house has a PRV, it goes to the UVC, but I have a manifold for cold services just teed off after the incoming PRV. The white top pipe going to cylinder.

I really just looked at the risks. Coldest day AND many hours of power cut is required to get insulated pipe contents down to atmospheric temperature. At any other time the heat pump freeze protection program will look after you anyway. How many external oil boilers have antifreeze? Do you ever here of issues with frozen pipes? Adding some extra biocide I didn't concider so perhaps I should get some fernox F7 biocide.

You get the G3 cert covering you for English and Scottish Regs and hygiene cert for domestic hot and cold water systems. So you can design, install and self certify UVC installations. So can produce the commissioning certificate, and recertify annually also. If you need to register a cylinder install seewith local council you can do that also. But they do not need to come out to any validation or such.

But that is the only vehicle being offered by Octopus for V2G!

Tell that to my phone. Did you see the top gear episode here they tested a used Nissan Leaf, about 5 years old and the range was less than half of what it should be.

They are giving free charging - you don't stuff like that without payback. Words from the website We’ll set up your V2G charger to automatically manage your charging and discharging in the greenest way possible, so you can fill up for free. and then export back to power your neighbourhood when the grid needs help

Or just go to Screwfix, Flomasta concentrated antifreeze, it's Monopropylene Glycol based anti-freeze with additional anti-corrosion & anti-limescale components. I am doing between 15 and 20% Dose Rate 25% = Freezing Point - 11°C Dose Rate 30% = Freezing Point -15°C Dose Rate 35% = Freezing Point -18°C Dose Rate 40% = Freezing Point -22°C

Not sure I would sign up unless the car was leased. Suspect they will be borrowing your battery power to suit the network, not your car battery life. Note the title V2G not V2H - grid not home.

"Which" has reviews of various heaters, you need to subscribe for a month to get at the reviews. Things to watch for, some heaters have thermostats other don't, some measure the heater temperature and others the air temperature. Some have timers others don't. For me you want A timer A thermostat that measures air temperature A switchable output rating I bought a Dimplex heater from Screwfix which had all the above Dimplex ECR20Tie Freestanding Oil-Free Radiator with Timer.

No idea, but duplex ones will be going in when I'm finished. Whole design is pretty poor overall.

Possibly the pump stops and starts on the valve microswitch? so pump doesn't stop until valve is fully closed. You could just be hearing the high velocity water going through an ever smaller opening in the valve?

If you go to a plumbers merchant you can get 35mm x 15mm insulation, goes over Hep2O fittings nicely.

I am doing an offshore job at the moment they have a pH of 5 from the water they make (reverse osmosis), and have been using copper unvented cylinders, which have to be replaced every two years, as they start to leak. Think the slight acidic nature stops the corrosion skin forming and copper disappears quite quickly. So good call on the use of tap water instead of rain water. You still end up eating the base material away, as the corrosion skin is just base material corroded. So each cycle takes the odd micron of material away. I would be tempted to add a gate valve and simple flow meter downstream or a flow setter, you can tune the flow rate, to get the best compromise between reheat time and lowest erosion risk. Add it to section of 22 or 28mm prior to reducing down to 15mm.

So some questions You are using a Nest controller, how are radiators configured have they got TRV's on them? Do they all close down when Nest is finished heating or do they all stay open? What exactly does the Nest bits bring to the system and what do they control? Do you have by pass valve in the system? To me it sounds like the zone valves on the pre plumbed cylinder are closing (are they?)while the pump (or pumps) are still running. So pumps are pumping against a closed valve.

No don't discount anything. But why heat on a routine basis above 50 and take a kicking with rubbish CoP when the sun's not out and you have no PV to use. A PV diverter will power the immersion but be a CoP of one, but it's free energy when it would otherwise go back into the grid.

Can you take a photo of the flow and return pump settings and the set up of the valves and label what they do. It makes a noise but not easy to diagnose without having a basis to diagnose against. Information is is good.

Sounds like you have the basics approved i.e. house will look like this and X number of bedrooms etc. You now need the detailed drawings, in Scotland that would be move to the building warrant stage, think it's the building regs stage in England. In Scotland you would also have a full structural design package. That would detail much of what you are asking. Soak aways need to be designed and are based around a percolation test of the soil. Never seen why people build a house with a cold air stream blowing below the house, but many think block and beam is great. 1. Engage an architect or architectural designer to get the details sorted and approved. Then you start at the bottom and build up. Foundation design will depend on the site and conditions it could also vary depending on house construction type.

Buy one and do not connect until you do. You could do more than one inverter, two trackers inverter is easy to get and then add a second inverter. We have three arrays, done that way.

Starting at one end the first connection goes to the isolator via an extension. You then connect positive to negative along the string. The last panel will have a spare end, this end goes to the isolator, your isolator now has a positive and negative. Depending on panel voltage, you now a voltage that will kill you, so be careful.

Your planning authority should have given a list of what they require to see and a sign off form. If you can't find it the planners should be able to issue a duplicate. Basically give them only what they ask for. Then someone will come and do a final inspection.

Really depends on location of heat pump and plant room or cylinder location. If you just can go through the wall two holes in wall - done.

Why are trapped into a 5 or 12kW heat pump, plenty of sizes in-between to choose from. Size so you have two to three hours for DHW and rest of the time to do house heating at your design temp. If you have your heat pump running 24/7 it will automatically utilise your PV, time DHW heating at around midday when most solar is available. You also need a PV diverter, heat pump heats cylinder to 50 and immersion takes it to 60. Heat pump will have a minimum flow rate and volume of water that must be engaged at all times. If you have zones that do not meet both requirements, you need to make a system that does meet them. So now you need to read up on volumisers, buffers (2, 3 and 4 port) and close coupled tees (CCT). They can all be used to get what you want, with differing affects on efficiency. The more simple the system the better the efficiency generally, heat pump direct to heating system (via a 3 port diverter), controlled by manufacturer controller is best. No third party stuff to mess things up.

There are several grades of glycol, the stuff used in heating systems is food grade, it doesn't poison you. Stuff used in cars does.

Maybe, you have to checked if your heat pump will modulate the circulation pump when doing DHW, mine just goes to full speed and stays there until DHW cycle is complete. Also have you checked the pump curve, to verify the actual flow rate you achieve with your expected pressure drop. The bigger the pressure drop (head required) the lower the flow rate you get.